D. M. Griffin, Jr., PhD., P.E., D.WRE
"The Wizard"
Contractor Trust Fund Professor of Civil Engineering




                                                                                                                                                                                                                                                                          

     Why...nobody gets in to see the Wizard, not nobody, not no how !

Eight Time Winner of the Prestigious
"Crying Towel Award"

Bestowed annually by the students in the civil engineering
program on the faculty member responsible for inflicting
the most mental anguish during the Year

Course Materials
and
MathCad File Distribution Page(s)


 page last modified 8/22/2009, 3:30 pm

Resume :  Resume

Current attractions

2/22/07  - Chemistry problems can often exhibit convergence problems, depending on how the equations are writtem, in the CVEN 314 section

2/11/06  - Are minor losses really minor ?  In the fluids section

2/21/06 - The potential effect on clarifier size when laminar flow around a settling particle is assumed....but isn't occurring 

3/11/06  -  Determining the operating point, brake hp and efficiency of a cetrifugal pump. 

3/19/06 -  The concept of Net Positive Suction Head, NPSH, and how to determine it

5/18/06 - Sensitivity analysis of Green Ampt infiltration procedure - in the student section

5/29/06 - A discussion of the vector product as a tool in dynamics, in the dynamics section

6/4/06 - An application of the vector cross product with explanation and several schematics.

8/2/06 - A neat little chemistry problem exploring calcite solubility, excellent application of a solve block

8/6/06 - File demonstrating use of a "parameterized" solve block for solving a chemistry problem

8/13/06 - An interesting file for a nonchemist showing what happens when the salt of a weak acid is added to water

8/13/06 -  The strong acid in water problem

8/15/06 -  Species distribution in a CO2/water system open to the atmosphere

8/15/06 -  Water containing soluble calcium and solid calcite, subject to partial pressure of CO2

                    You can access various problem topics by clicking on the following targets :

Course Materials for Contaminant Transport 
Notes, Derivations, Discussions for Contaminant Transport
Materials for undergraduate environmental engineering (314) class
Air Pollution
Chemistry
Probability and Statistics
Civil Engineering
Misc. Problems
Numerical Methods
Fluid Mechanics
Dynamics
Water Resources I and II -  CE 310 and 411
Mathcad Procedures
Files developed by former students





                 

 
                                                                    


A couple of Ruston, Louisiana's finest - The 2005 Mardi Gras Ball
 

 
 
 
 
 
 
 
 
 

  FILES DEVELOPED BY CURRENT AND FORMER STUDENTS


FILE  FILE DESCRIPTION AND DEVELOPER    
A File from Katrina Developed by Rel Gray, currently with Hunt-Guillot and Associates, Ruston, La This was done in response to a contract from development of temporary living quarters for victims of hurricane Katrina, posted Nov. 1, 2005
Drainage and Detention Basin Design This file is several years old.  It was done by Michael Foster.  "Foster" did not like hydraulics/hydrology or Mathcad and said he wasn't going to work in the hydraulics area or with Mathcad after he left school, "he was going to do structures".   He went to work for a firm that does structural work in the electrical power industry.  Unknown to Foster, the firm also has responsibilty for drainage around their structures.  This was Foster's first assignment.  Moral of the story "In private industry you do what comes through the door"
Sizing of Culverts - Minimum Performance Approach This file was produced by Lance Tyson in CVEN 411 (Fall 2005).  It uses the minimum performance approach (FHWA) to size culverts.  Posted Nov. 5, 2005.  Nice use of conditional statements with text strings as output.
Sensitivity Analysis of the Green Ampt Infiltration Procedure This file was produced by Joseph Bramande.  He uses an "iterative input" into an Excel component to do a sensitivity analysis of the Green- Ampt infiltration procedure. Posted May 18, 2006, 9 am
Detention Basin Simulation
This file models the performance of a detention basin, it actually consists of 5 files.  Very nicely done.  Developed by a current student Keith Stagg, PDF version, posted 2/5/09, 3:30 pm

 



 
CHEMISTRY
(some are annotated better than others)
File
 

Description of File

  Strong acid strong base titration
version 1 - solve block
Numerical solution of a strong acid strong base titration with associated plots 
This file details the development of the titration curve for a strong acid/strong base system.   This file uses the "root function" rather than a solve block and results in a very general template .
chemistry problem
  Total dissolved carbon in a solution in contact with solid calcite
  PDF version of file above
PDF file of file above
  Chemistry Problem
    pH of rain water from an acid atmosphere
Chemistry Problem
partial pressure of CO 2 in solution
  Chemistry
  A discussion of alkalinity in natural waters 
  Sodium bicarbonate addition for pH control and buffering
This problem arose as a result of the need to predict the pH and alkalinity resulting from the addition of sodium bicarbonate to a low alkalinity well water.  We defined a function,  fct(Na), which calls a solve block for each dosage. Resulting pH and alkalinity plotted vs dosage. 
  Master Variable Diagram for H2S Species
Species concentrations as function of pH
Ammonia Speciation
Problem deals with computing the ammonia/ammonium distribution in water
  H2S concentration in a section of Sewer
  Calculations to determine the speciation of H 2 S in section of sewer. Comments on the practical use of such calculations
  Solvent Spill
  Calculations relating to evaparation of solvents after a spill
  Fog
calculations dealing with pollutants in fog vapor 
  Alkalinity Equations
  Numerical and analytical calculations for computing alkalinity
  Development of alkalinity equations
Development of concepts and equations used to quantify alkalinity in natural waters
  pH of weak acid solution - 2 weak acids
Numerical solution of the salts of 2 weak acids in water
  Chemistry
  Alkalinity of a sodium bicarbonate-sodium carbonate solution - solve block used
  Examination of alkalinity variation in solution
Carbon at varying pH-alkalinity levels
  System with constant carbon concentration
Find the partial pressure of an acidified system where the aqueous C concentration remains constant
  NaOH added to CO 2 /water system
  NaOH is added to a CO 2 /water system to produce NaHCO 3
  Sodium hypochlorite added to water
  The effect on pH of the addition of the salt of a weak acid to water
  Magnesium precipitation
Effect of buffer on requirements for precipitation. Based on problem from Snoeyink and Jenkins text
How much Freon in the bottle ? 
A neat applied problem using a little chemistry and a little thermodynamics. From the Environmental Organic Chemistry text by Schwarzenbach et al.
Another neat problem from Environmental Organic Chemistry by Schwartzenbach, et.al , posted 5/1/03, 4:40 p.m.
  Methyl Bromide on lettuce leaves
A very practical little problem from Schwartzenbach et al. but I'm not sure if my solution is correct. Anyone seeing a mistake is asked to email me. Posted 2/25/00 8:30 am
  Stumm&Morgan/7-1_solubility_of_FeCO3.mcd Solving for the soluble Fe +2 concentration when the system contains a buffer system. Posted 12/15/01, 8:41 am.
  9-6_iron_oxidation_kinetics.mcd
Problem illustrates that equilibrium calculations don't tell the whole story, posted 12/20/01, 7:15 am
        8_1_biochemical_calculations_M@E.mc
A neat little problem from Metcalf and Eddy which draws together material from different areas to compute the oxygen requirement for metabolism of casein, posted 1/18/02, 1:45pm
Engineers are not chemists - this is a very simple little problem where I examine an often used approximation in acid-base chemistry.  The use of Mathcad solve blocks does not require many of the assumptions made when solving chemistry problems manually or graphically.
Open system with solid phase
Here I solve an "open system" in contact with a solid phase for a range of the independent variable.  I used a "solve block function" .  This is an iterative form of a solve block not documented in Mathcad literature, at least not very well.  Posted 4/6/03, 11:05 am
A problem from Stumm and Morgan's Text, posted 4/14/03, 12 noon
  Shows how to determine if CaCO3 precipitation will occur and how much , posted 4/29/03, 3:30 pm
  A kinetics problem dealing with chlorine residuals.
Posted 5/14/03, 10:24 am

Reverse Osmosis Fouling Calculations

A Problem from "Water Treatment" 2nd edition by MWH Global  (GREAT BOOK).  I tried to add a little chemistry explanation as well as a drawing, posted 7/25/05, 3:30 pm
CaCO3 Solubility  A neat little problem exploring the solubility of calcite in an open system with the presence of a solid phase.  Much written explanation.  These types of problems are an excellent application of solve blocks, posted 8/2/06, 7:15 am
Use of a parameterized solve block for weak base addition This is a slick little problem showing how to use a solve block as a function with 2 independent variables that has ranges.  The equations defined in the solve block are solved for each value of the independent variable(s), posted 8/6/06,  10:20 am
Adding strong acid to salt of weak base File illustrates the effect a small amount of weak base has on pH reduction when a strong acid is added.  Nice use of a solve block function, posted 8/6/06, 4 pm
Solubility of Silver Acetate in Water and the resulting pH Interesting file for a non-chemist.  I was surprised that adding AgAc changed the pH of water.  It's because Ac- is the anion of the weak acid HAc.  Posted 8/13/06, 9:05 am
Numerical Solution of the strong acid - water problem with explanation Here I "beat to death" the strong acid in water problem.  Both a numerical and analytical solution are provided as well as chemistry and Mathcad explanations, posted 8/13/06, 2:45 pm
CO2 - water open system - alkalinity zero Species distribution in a CO2 water system open to the atmosphere - key point is that in such a system the alkalinity is zero, posted 8/15/06, 7:05 am
 water containing solid calcite subject to p.p. of CO2 What effect does the soluble Ca concentration on partial pressure of CO2 (or vice versa), posted 8/15/06, 4:30 pm




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     A classic ....... Mardi Gras 2005














                                                                                                                     

 
AIR POLLUTION
Air Pollution Problem
Air  flow at non-standard temperature and pressure. Notice that this problem is basically a fluids and gas law application
  Air Pollution Emissions
Particulate emission calculations
  Air Pollution - Puff Model 
A simple steady-state air pollution model - uses a Mathcad surface plot for illustration
  Air Pollution
  Flue gas flow calculations
  Coal combustion analysis
  Stoichiometric analysis of coal combustion
  Unit conversion for concentration unit in air pollution
  converting ppm to micrograms per cubic meter- a discussion and some examples posted 11 am, 6/20/00
  PDF version of previous file
  PDF version of unit conversion file with discussion and explanation, posted 11 am, 6/20/00
   

 

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                                      PROBABILITY AND STATISTICS
  probability problem
A probability problem which computes the odds of winning a lottery
An interesting probability problem
A cool probability problem from the best seller "Innumeracy" by John A. Paulos
Statistics-Chemistry Problem
A statistics problems using pH data. Uses many of Mathcad's statistical functions
Linear Regression
A simple but insightful problem using linear regression
Linear and non linear parameter estimation
  parameter estimation in an environmental problem
  Statistics using pH and DO lab data
  Shows what can be done with even simple data sets - A PDF file
  Kruskal_Wallis.pdf
Based on a file from a Mathsoft E-book on statistics. Illustrates the Kruskal-Wallis procedure and explains some of the more esoteric Mathcad statements used. The test is a nonparametric version of ANOVA.  A PDF file, reads external data sets. Posted 6/21/00 7:05 am
  Mann_Whitney.pdf
Based on file from Mathcad ebook. Nonparametric version of the t test. A PDF file. Posted 6/21/00 7:40 am
  Monte Carlo Methods using a normal distribution
Based on a file taken from the Mathcad Treasury. I tried to dress it up a little and add some explanation and a possible application so that the user can learn a little statistics as well as Mathcad. posted 11/24/00, 12:55 pm
This illustrates the fact that sample means are normally distributed even when the underlying population is not. However you must collect alot of samples with a few observations per sample or fewer samples with many observations per sample. Posted 11/28/03, 10:30 am.  This is repost of a (hopefully) better version of an earlier file.
A hydrologic example of the use of the binomial distribution, posted 3/5/01, 5:10 pm
A problem illustrating the value of a bivariate normal distribution in making predictions, even when data sets are only minimally correlated , posted 7:35 am, 8/30/02
Type III extreme value distribution
  Comparing a Type III EV distribution to a reference distribution created directly from data, posted 6/27/03, 2:40 pm
The Gamma Distribution
This file steps through an example problem using the Gamma Distribution.  I try to show how the 1 parameter, (s), version in Mathcad is related to the normal 2 parameter version,(l, k) cited in most texts. Posted 8/2/03, 8:35 am
Binomial Distribution Problem - Benjamin and Cornell
A nice hydrology application problem from a very good text - Benjamin and Cornell, posted 8/4/03, 9:35 am
Bayes Theorem - C.T. Haan
A nice little problem from Haan's text illustrating the use of Bayes theorem.  I extended it a bit and tried to add explanation, posted 9/15/03, 5:10 pm
Basic Probability Concepts - Kottegoda and Rosso
 Basic probability concepts (union, intersection, conditional probability, independence) applied to dam failure .  I added a little to the basic problem from Kottegoda and Rosso.  Don't let the minor notation change between 2-14 and 2-19 confuse you. Posted 9/28/03, 9:35 am. 

The Normal Distribution and Mathcad

Just a refresher on the normal distribution and Mathcad functions used in connection with it, posted 10/24/03, 11:45 am

TYPE III extreme value distribution

Fitting an empirical distribution of low flows to a type III extreme value distribution, posted 10/30/03 8:10 a.m.
Data file for Type III extreme value
distribution problem above

This is the data for the problem above, posted 11/1/03, 7:25 am


Pearson Type III distribution

I have never seen this done for either a Pearson Type III or an LP III distribution.  Most texts use the frequency factor approach where magic K values are selected from mysterious tables.  This needs to be done in hydrology classes.  Posted 11/13/03, 4:10 pm.


LP III distribution using data from Bulletin 17 B

Here I fit the data used in Example 1 in Bulletin 17B using the actual distribution, not frequency factors.  I get the same answer.  This procedure is not illustrated in any hydrology reference I have.  Posted 11/14/03, 12:05 pm

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                                    CIVIL ENGINEERING
  Specific Energy plot and calculations for pipe
  From V. T. Chow's book, a simple specific energy problem with some bells and whistles added
BOD problem
Problem uses real data collected from a malt plant in Moorhead Minn.
Uniform open channel flow
A simple problem computing normal depth in a channel
  Clear water transfer capacity of aerator ANSI/ASCE 2-91
Shows both linear and nonlinear regression procedures
  PDF version of the file above
Here it is - let me know if you want assistance 
interpreting it. The second part of the document is the ASCE standard procedure.
  Normal depth in a triangular channel
A discussion of 2 methods for dealing with Manning's equation when looking for flow depth, posted for Water resources II class, 8/16/00, 10 am
  Hydrogeology - groundwater plume
  2 dimensional solution - long time frame. Uses a surface plot to present results
Model of an Ant colony
Mathematical Model of an ant colony using data from
an American Scientist article
Must reading for municipal engineers
  PDF file for the problem above
Same file as above but in PDF format 
  A PDF file for the Ant colony problem
PDF File
A neat little problem from Henderson's classic open channels text. Enlightening computations regarding the conditions for hydraulic jump formation.
An optimization problem - Sewer pipe
 Based on a problem from the text by Ozzenbrugen
  PDF version of sewer optimization problem above
PDF FILE
  Acrobat version of reservoir computations file
PDF File
  hydrology/land use problem
An enlightening problem showing what happens when urbanization occurs. Required reading for developers and local officials
 Solve the same problem analytically and numerically
  Chlorination/chemistry problem 
  An extension of a simple chlorination problem from the text by Davis and Cornwell, 3rd edition. We included the ion product of water as one of the equations to be solved.
  PDF format
Same problem as above but we neglected the ion product of water in order to examine the effect of leaving it out
PDF Format
  An all purpose trickling filter design file using the NRC equations
Inputs needed are the influent BOD, flow and desired effluent BOD
  Tray settler analysis
An extension of a problem from the text by
"Metcalf and Eddy" based on type I clarification principles
  PDF version of tray settler problem 
An extension of a problem from the text by "Metcalf and Eddy"

THE TOP



                                                           
                                 
                                                                                                                        

 
  
                                                   Fluid Mechanics 
      A simple pump cavitation problem
Extended for a variety of water temperatures
       Mays_12-2-4_NPSH_available.mcd
Computing the net positive suction head required for a pump
A neat little discharge problem
  An observation that needed explaining. Based on a small consulting assignment
  Control_valve_selection.mcd
An algorithm for contolling flow in a pumped system using a valve. Originally posted by Andrés Felipe Ortega Montoya, Chemical Engineer - Universidad Pontificia Bolivariana - Medellín, Colombia.
E - Mail: aortega@janua.upb.edu.co. 
I just added some comments and dressed it up a little, posted 7/3/2000
Control_valve_selection.PDF
  PDF version of the file above, posted 7/3/2000
pump_station_design.PDF
PDF version of problem 9-1 from Wastewater Engineering, collection and pumping of wastewater. posted 7/16/00 
  Measuring flow with American Sigma equipment
In this file (a pdf file) we read in 2 external data sets. One was logged using an American Sigma 950 data logger attached to a 4" McCrometer water meter with transmitter. The other was logged using an American Sigma ultrasonic level sensor attached to a second 950 unit. We then carry out the necessary calculations to compute flow volumes. This data comes from an Interstate rest area on I-55 at the Louisiana/Mississippi border. Real world stuff....posted 12/24/00, 2:15 pm
Headloss in a horizontal pipe, f not known a priori Solution uses a solve block. Problem illustrates the fact that pressure gages can have same reading in flow through an inclined pipe. Could not happen if pipe was horizontal. posted 11/19/00, noon


Fluid mechanics for real people

Based on an on-going research project.  The insensitivity of the flow rate to the length of the discharge line was unexpected.  Numerical  methods used to get the equation for the pump characteristic, the rest is fluids.  posted  7:45 am  9/7/03
link
How can you have pipe flow when the pressure at two different points is the same ?  Posted 8/22/09, 3:30 pm




Analysis of reservoir gate


This is a file I found on my hard disk.  It was apparently oringinally done by either Mathsoft or perhaps the Schaum's outline people.  In any case it was a bare bones solution.  I have added alot of description and text in the hopes of making the problem understandable to undergraduates in a fluids class, posted 3/30/04, 11 am
Flowrate when pressure drop is zero

Analysis of Tainter Gate Analysis of Hydrostatic force on a Tainter gate.  I have included several drawings showing how each component can be visualized, posted 1/15/07, 8 am


Depth of water needed to open gate

This problem comes out of Hydraulic Engineering Systems by Hwang and Houghtalen.  Its pretty straight forward.  I just beat it to death.  The drawings were done with Visio.  I set it up so system parameters could be easily changed.  Posted 1/12/05, 9:45 am

Statistics in Fluid mechanics

This problem appears in Frank Whites Fluids text.  It can be solved by linearization but I chose to do it using nonlinear regression, posted 4/4/04, 9:25 am


Pipeline diameter required for flow

A standard pipeline solution using a solve block.  I have tried to make the template somewhat general in nature.  The equations in the solve block are put into "ratio form" for improved convergence. Posted 4/10/04, 8:15 am.  Note that the minor losses aren't in this problem.


Time Required to Fill a Water Tank

This problem is from Gearhart, Gross and Hochstein, 2nd edition.  I like it because it combines basic fluids and the solution of a differential equation.  However, for the second part of the problem I got about 6.4 hours whereas the text got 18.2 hours.  If you see an error in my solution let me know. Posted 6/11/04 7:25 am.

Tainter Gate Problem

A simple hydrostatics problem involving a tainter gate.  I added drawings to try to better illustrate the components of the vertical hydrostatic force, posted 1/21/05, 8:10 am


Flow between Reservoirs

This is a problem from Hwang's hydraulics text.  I do it assuming complete turbulence and then numerically, making no such assumption.  It appears that the complete turbulence assumption should be made cautiously. Posted 2/20/05, 4 pm


The complete turbulence assumption
I have become fascinated with how difficult it can be to make the "complete turbulence assumption" and get away with it.  If the Reynolds number is low, substantial differences in computed flows can occur.  Posted 3-1-05,
9 am.


Flow to shower head

This shows the kind of problems that can be solved in an undergraduate fluids class using Mathcad.  The student can think at a more abstract level if Mathcad does the busy work, posted 5/9/05, 6 pm

Illustrates computation of the pressure-force on the underside of a cylindrical dome, posted 6/19/05, 9:35 am

Static and dynamic pressures across pump
This problem illustrates the interplay of static and dynamic pressure changes across a pump.  Posted 6/20/05, 10:40 am
Pipeline between Reservoirs - Iterative Solution Just another simple pipeflow problem with explanation.  The problem says to ignore velocity at the outfall so I explore the validity of that assumption...easy to do with Mathcad posted 1/27/06 8:45 am
Are Minor Losses always minor  This problem takes a look at "minor losses".  It ain't always the case.....posted 2/12/06, 7:30 am
Buoyancy - Water line of  a tethered buoy This problem looks at how high the tide must rise to float away a buoy with a brass anchor. posted 1/17/06, 3:30 pm
Pipe Friction Loss Experiment The results of a fluids lab experiment examining head loss in laminar and turbulent flow,  uses an Excell spreadsheet inside a Mathcad file.  posted 1/18/09, 2:30 pm

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                                              MISC AND UNCLASSIFIED PROBLEMS

  An Ion Exchange problem Computation of the capacity of an Ion exchange resin and other relationships. Uses the spline algorithm in Mathcad

A worksheet for BOD analysis    Worksheet computes reaction rate constants as well as BOD 5 for three different, seeded dilutions. Compares fitted BOD equation to observations for each dilution.

  Laplace_transforms_RHS=0_data_set_1.mcd Solution of two coupled second order ODE using Laplace transforms.  Uses a solve block for a symbolic solution - I had not seen this before.  Also uses keywords for symbolic manipulation.
 
  Ammonia Assimilation    -  A pretty straight forward problem showing how to compute quantities in ammonia assimilation in biological waste treatment, posted 1/19/2009, 3:45 pm
 

 
 
 
 
 
 
 
 
 
 



                                        A closer examination of statements and procedures in Mathcad

Unfortunately many of the most powerful Mathcad capabilities are not well documented, or the documentation is not in one place. The files below attempt to provide some better explanation of Mathcad statements and algorithms.  Some attempt to demonstrate how the more powerful features (programming, solve blocks, root solvers) in Mathcad can be combined.  Email regarding mistakes, incorrect interpretations or ambiguities is welcomed. dmg@coes.latech.edu


Local assignments - A good start for those who want to learn to program - This file comes from the Mathcad Treasury. I doctored it a little to, hopefully, make it easier to understand. posted 11/15/00, 2:16 pm

An_interesting_statement.mcd    A close examination of a Mathcad statement that isn't well documented in the existing manuals

  iterating_a_solve_block.mcd I got this file off the Mathcad Web site. The file itself is essentially unchanged. I tried to add to and rewrite the explanation. Iterating a solve block is a very powerful tool that is not explained very well in most places. Posted 10/28/00 noon

calling_solve_block_from_program.mcd - The original of this file came from the Mathsoft web site but, in my judgement, it is not documented or explained very well. I have added considerable explanation and tried to make the procedure easier to follow for the non-expert. Posted 10/30/00 11:45 am

  finding and extracting soln values meeting a condition - The original of this file also came from the Mathcad Web site. It involves finding a set of solutions with a solve block and then uses a program function to extract those values meeting a specified condition. I just dressed it up a little and added some explanation, posted 11/4/00, 11:20 am

  Examples of 'while' loops - I have taken some simple examples of applications of while loops and added some explanation. I also note where the operation of the program seems confusing. posted 11/5/00, 11:05 am

  breaking out of a loop - A simple, annotated, example showing several ways to break out of a loop, posted 11/5/00, 11:10 am

  Using the root function repeatedly and storing the output - Here we use the root function to solve a single equation many times. The results are stored in a matrix. posted 11/5/00, 11:20 am

  Examination of the Conditional statement   - An example from the manual with a little bit more explanation -  posted 11/11/00 11:40 am

  A program for extracting vector element locations - A minor change in an existing Mathcad quicksheet allows one to extract all locations (rather than values) of the maximum valued element in a vector. Posted 11/14/00

  A file showing the definition and use of Boolean type functions - File originally from Mathcad Web site. I dressed it up a little and added some explanation. File also uses uniform random number generator, rnd(x). Added 11/22/00, 7:30 am

  Elementary row operations - This file originally came from the Mathcad web site. I have tried to disect it a little and add additional explanation for the non-expert. posted 12/27/00,
7:25 am

  symbolic solution using keywords   - Here we solve a separable differential equation using Mathcad keywords, posted 2/1/01, 11:40 am

  multiple_SB_for_simultaneous_equations.MCD - This is an interesting file demonstrating the repeated use of a solve block coupled with a small piece of Mathcad code. The file solves two simple equations repeatedly. Posted 6/4/02, 7:30 am

Plotting 3-D Space Curves  -  I developed this file because I had a very hard time figuring out how to rationally a plot a space curve using cartesian, spherical or cylindrical data.  The documentation in Mathcad is not very good.   See if this is understandable, if not email me and tell me.  Posted 8/5/05, 9 am.
 
 

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                                                                                            NUMERICAL METHODS
 
 
click on underlined portion to bring up file



ALGORITHMS FOR SOLVING SINGLE EQUATIONS

Secant Procedure    An illustration of the mechanics of the secant procedure for finding roots of equations

  numerical_methods/False_position_algorithm2.mcd A study of the number of iterations required for the family of functions: xn - 1

Newton Raphson Algorithm Here used to solve the Colebrook White equation. The C-W equation is used in fluid mechanics to determine the friction factor for flow in pipes. A graphical description of the procedure is included.  

numerical_methods/Redlich_Kwong   Here I explore the convergence properties of two forms of the Redlich Kwong equation of state, posted 9/22/02, 10:45 am

falling_object_fixed_point_method.mcd  A simple problem exploring the fixed point solution procedure and its convergence properties, posted 9/26/02, 11 am.

Motion with resistance, numerical integration   A simple problem dealing with the time required for a particle to decelerate.  Corrections for units are required.  Posted 7/30/05, 3 pm.


Numerical Integration   Computing the area of a stream cross section. A common calculation when modeling streamflow. PDF version below. Uses several versions of Simpsons rule to compute the integral.

  PDF file for numerical integration - A PDF file version of the problem above



FINITE DIFFERENCE APPROXIMATIONS

Finite Difference Approximations of the First Derivative   A comparison of the foward, backward and
centered difference approximations with the analytical derivative

Euler's Implicit Method for solving the Advection Equation     - A finite difference approximation . This file requires that the" Thomas" algorithm for solving the tridiagonal matrix generated.  It is in the same directory and should work fine. File was produced using version 11.  Posted 11/27/02. 2:15 pm

A finite difference approximation for the solution of the
steady state advection dispersion equation   - The solution is for a reactor. Could be a river also.

Modified Lax Method applied to the advection equation - Can change flow velocity to show what happens when stability criteria are violated. Useful for predicting bulk motion.

  modified_lax_method_applied_to_advection_equation.PDF   - PDF version of the file above



EULERS METHOD

The Basics of Euler's Method   A simple problem illustrating Euler's Method for solving ordinary differential equations

Predictor corrector modification for Eulers Method   This file uses subscripts instead of Mathcad programming to carry out the procedure. This requires that the procedure be cast using a single variable name subscripted for time. Solves the radiation equation.

Numerical solution of the radiation equation  Use the modified Euler predictor-corrector method. This version uses Mathcad programming. As a result, differing variable names can be used. Solves the same radiation equation as the file above.

Numerical solution of a stiff ODE   Uses the Euler explicit solution technique

A PDF version of a stable and unstable soln to a stiff ODE  Same as the problem above PDF version
Note - One definition of a "stiff ODE" is an ODE in which the solution function exhibits rapid and extreme changes in the dependent variable with small variations in the independent variable. As a result a plot of the solution function over long time frames (time is the independent variable) will look quite different from a plot over short time frames.

An example showing progressive instability in Eulers Method   A nice example showing progressive instability as a function of the size of the time step

  A comparison of 1. analytical 2. Euler's explicit and 3. Leapfrog method Three ways to solve the same problem. An examination of the relative error for the numerical methods

  Solution of a 2nd order boundary value ODE   In this problem the derivative of the depndent variable is assumed, then adjusted until the right hand BC is met. Consideration of mesh size is examined. "Odesolve" also using for a comparative solution. posted 8/6/00, 5 pm

  PDF solution for the problem above   Same problem, in Adobe for non-Mathcad types, posted 8/6/00, 5 pm



PREDICTOR CORRECTOR METHODS

  Second order boundary value differential equation - heat loss along a rod - A comparison of (1) the internal algorithm "odesolve" (based on 4th order R-K procedures), (2) a Mathcad programming solution in which the second order equation is reduced to a system of first order equations, these are then solved using the modified Euler predictor corrector procedure and (3) the analytical solution to the second order differential equation describing heat loss by convection and conduction along a rod, posted 8/6/00 7:45 am

  A PDF version of the heat loss from a rod problem - Same problem as above,  in Adobe for those who don't have Mathcad, posted 8/6/00, 7:45 am



RUNGE KUTTA PROCEDURES

The basic difference between the various numerical procedures used to solve ODEs is the way in which the functional relationship BETWEEN the points on the solution function is approximated. While Euler's technique is one of the simplest, using a linear approximation, the Runge Kutta procedures use more sophisticated relationships.

  A comparison of 2 numerical procedures- Euler explicit and 4th order RK    A comparison of these methods used to solve the radiation equation. Here we use the Mathcad function for the 4th order R-K procedure rather than code it directly.

  A discussion of R-K 2nd order solution technique and an example   - A mathcad file. Here I try to give some introduction and backround regarding the solution procedure. The procedure is demonstrated on a badly behaved function

  The Runge Kutta Fehlberg Method   - This procedure allows for efficient determination of local truncation error. A Mathcad file. E-mail me if you think my analytical solution is incorrect.  

numerical_methods/gradually_varied_flow_Runge_Kutta.mcd  - Mathcad programming used to implement the 4th order R-K procedure to plot a water surface profile , posted Oct 13, 2002 , 10:45 am

2 Lakes in series - This file uses both the R-K fixed algorithm in Mathcad as well as a Mathcad program to solve ODEs related to contaminant concentrations in a lake.  Posted 11/12/02, 7:50 am






ANIMATIONS
  An animation file - This is an avi file showing an animation of the advection equation. A square wave is used as the initial condition


APPLICATIONS

A numerical solution to estimate the volume of a rock cap for a dike
  -  This problem was the result of a call from a fomer student looking for an "easy" way to estimate
the volume of rock required  to "cap" and existing dike in south Louisiana.  The key here is splining the survey data and realizing that Mathcad knows the equations making up the splines.  This allowed for easy numerical integration.  Posted 2/18/07 8:50 am.
 
 

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                                              COURSE MATERIALS FOR CE 314 - Environmental Engineering
                                                                          Click on the underlined item to bring up the PDF or Mathcad file
 

Assorted Problems and notes - click on the underlined portion to open the file, most are in PDF format

Nonlinear regression to determine BOD rate constant   Here I use nonlinear regression to obtain the reaction rate constant, k, and the ultimate BOD, L.  This seems easier than the earlier, manual methods, e.g. Thomas slope, etc.   Note that I also compute the statistics for the model fit Posted 5/9/03, 8:50 am

Problem 3-17 3rd edition Davis and Cornwell PDF file
  Chlorination problem ion product of water not included

Problem 3-17 3rd edition Davis and Cornwell. In this version the ion product of water was included in the solution.  PDF file
  Chlorination Problem - includes ion product of water

  Problem 3-23 A simple alkalinity calculation makes use of the mathematical definition of
 alkalinity - PDF file
  A simple alkalinity problem

  A problem from Davis and Cornwell illustrating calculations relating to alum addition
3-37 Davis and Cornwell - alum addition

Problem 3-31 Davis and Cornwell dealing
with hardness calculations - PDF file
hardness_calc.PDF

 Design of a rapid mix basin - The procedure with explanation(s) and justification for the choices made. posted 12/17/00 7am

A flocculation basin design  -  Very similar to the problem above, posted 2/25/05, 6:50 am 

A precipitation problem showing the effect of a buffer. In this particular problem the presence of a bicarbonate buffer increases the amount of base needed to raise the pH of the solution sufficiently to precipitate magnesium hydroxide by a factor of 16 ! PDF file
Mg_precipitation.PDF

Design of a primary clarifier
A primary clarifier design problem

PDF File - replaces 2 earlier trickling filter files
All purpose 2 stage trickling filter design file based on NRC equations
 

  IC distribution in an open system - Here I create a function which calls a solve block to find the inorganic carbon (IC) distribution in an open system for a range of partial pressures of CO 2 posted 12/2/2000, 7:20 am. The plot is commonly called a Master variable diagram. In this case the partial pressure of CO 2 is the "master variable"

  PDF version of the IC distribution file immediately above - For those who don't have Mathcad, posted 12/2/00, 7:40 am

  A simple solubility product problem   Here I take a simple problem and beat it to death. Hopefully the annotations and explanations are useful, posted 12/2/00, 7:30 am

  Simple solubility product Mg(OH)2   Just a simple solubility product problem with alot of explanation, posted 11/4/00, 3:55 pm

  A second order rate Process   A simple second order rate problem. Uses some of Mathcad's linear regression algorithms (slope(x,y) intercept(x,y) corr(x,y). Some explanation and examples of important rate dependent processes are given. Posted 12/8/00, 7:20 am

  A generalized Type I settling algorithm - using units - Uses an iterative solve block, with units, to compute terminal settling velocity of a spherical particle using Newton's law, Reynold's number equation, and C D -N R relationship. This is done using Mathcad 2001.

  Type I clarification - PDF file - Same file as above, in PDF format, posted 1/5/01, 7:25 am

  Hers's the Gp data set   - Here is the file

  E qualization_basin_sizing_and_analysis.mcd - Based on problems from Chapter 5 of Davis and Cornwell, 3rd edition. Also a little discussion as to why the concept does not always work well in practice. Posted January 25, 2002, 10:15 am.

5-20_problem_and_additional_HW.mcd     - A simple, complete mix activated sludge problem showing the interrelationship of the various equations used in design, posted 2/28/03, 7:25 am

Notes on Type I Clarification - Some basic notes on discrete settling, the concept of overflow rate, and some design parameters for horizontal flow, gravity type, grit chambers.  The technology is admittedly dated but the theory allows a nice development of the concept of overflow rate not possible for other types of settling.  Posted 1/27/04, 8 am

Alum dosage and sludge calculations  - A basic chemical dosage problem (from Davis and Cornwell) using alum as the coagulant.  Calculations for needed alkalinity as well as explanation of the process are provided.  Sludge volumes produced as a function of solids content provided.  Posted 2/2/05, 2:55 pm

The effect of assuming a Laminar flow regime on a particle's settling velocity    This file explores the error incurred when laminar flow conditions are assumed for the settling velocity of a particle, posted 2/21/06, 10:45 am

Iron solubility in water   This file illustrates the difficulties that can be encountered when using solve blocks to solve chemistry problems, posted 2/22/07 8:05 pm

Spray Irrigation   This file combines an Excel spreadsheet with Mathcad to compute the volume of storage needed for a spray irrigation operation, posted 1/23/09, 4:00 pm

NOTES, DISCUSSIONS, DERIVATIONS

Notes on type 1 clarification-PDF file- see the Type I settling algorithm in the section above also. Posted 1/4/01, 3:30 pm
Type 1 clarification notes

A discussion of the basic chemistry of alum coagulation. A PDF file
Alum coagualation at the Monroe WTP

  A Discussion of Chemical Equilibrium and the Ion Product of Water posted 12/4/00, 8:20am

  derivation of G - velocity gradient PDF file - posted 12/4/00, 9:20 am

  Using statistics on environmental data   An example of what simple statistics can be used for in environmental science/enginering - a pdf file, posted 1/14/01, noon. Data set used is actual pH data collected in lab by students, winter quarter,  2000-2001
 
 

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COURSE MATERIALS FOR CE 531 - Contaminant Transport

Files to assist students in solving ordinary differential equations are provided in the section on numerical methods in this web page. click here to go to numerical methods section
 
 
 
PROBLEMS
  volatization of an LNAPL
From Weber and DiGiano's new book
General discussion of Streeter Phelps Equation Here I use a simple problem as the means for developing the Streeter Phelps Oxygen Sag Equation, posted 7/1/07, 3:45 pm
           Monte_Carlo_Analysis_Streeter_Phelps.mcd An example of Monte Carlo analysis applied to the Streeter Phelps Equation, from Schnoors text posted 8/5/01, 7:05 am
From Weber and Digiano's book. The book has an error in the solution however. I note it in my solution. Posted 10/22/00
  transient response - equalization basin
Weber and Digiano 2-5; mass balance, transient response. A PDF file
  transient response for an equalization basin
Equalization basin with catalyst being added, problem 2-6 Weber and Digiano
  A simple mass balance on a conservative tracer
problem 2-7 Thomann and Mueller, a PDF file
  material balance on color
problem 2-4 Thomann and Mueller, a PDF file
  equalization basin
step feed, numerical solution required, PDF file
  Thomann and Mueller 2-8
A PDF file showing the use of conditional statements in Mathcad to screen and plot selected results
  VOC movement in a river
Benzyl chloride, PDF file
  VOC (PER) in a river
tetrachloroethene, PDF file
Lake Model comparison of numerical and analytical solutions
Uses Mathcad programming language and imbedded matrices, PDF file
Temporal_aspects_of_pollutant_loading_patterns.mcd
File illustrates use of Heavisied step function as a switch to turn on pollutant loads. Posted 10:25 am, Jan. 1, 2005
  Concentration from a distributed source
T@M 2-13 Illustrates the use of conditional statements to plot results - posted 1/7/2000 - 4:15pm
  Prob 2-8 T@M
Compute concentration(s) resulting from multiple discharges in an advective system, posted 1/26/00, 7:15 am. Conservative and nonconservative cases considered.
Step input - Analytical method, Euler's method and Heun Method
Example 7-1 Chapra
 Unsteady stae loading problem, complete mix system, solved 3 ways and compared, posted 12/28/04, 3:05 pm
  A simple problem examining mixing in an estuary
3-4 Thomann and Mueller - posted 1/16/00, 7:30 am
Good use of conditional controlled plots
  3-5 T@M multiple contaminant sources in a river
Good use of principle of superposition
  Instantaneous spill calculations
T@M 2-15 posted 1/16/00, 7:30 am
  T@M 3-14 Mixing in an estuary
defines bulk dispersion coefficient, posted 1/22/00, 7:15 am
  T@M 3-16 advective and dispersive transport
posted 1/22/00, 10:30 am
  T@M 3-17 mass balance, critical boundary condition
posted 1/23/00, 7:15 am, nice use of solve blocks to obtain the critcial downstream boundary condition for an estuary.
  Ex 4-1 T@M Lake response to pesticide discharge
posted 8:10 am 1/31/00, simple problem, makes use of Heaviside step function in Mathcad for describing input conditions
  4-2 T@M mass balance on P lake Ontario
posted 1/30/00, 7:50 am. Uses principle of superposition, shows the effect of even small decay rates in systems with long detention times, revised 6:30 am 2/3/00
  T@M 4-5 PCB Loading to Great Lakes 
posted 2/6/00, 7am, pieces together analytical solutions to describe the PCB concentration in Lake Ontario from 1950 to 1985.
  Level 1 atrazine analysis
Development of equations for toxics, discussion of removal mechanisms, posted 2/21/00. 9:40am
  Level 1 DDT analysis
Compare the behavior of atrazine with that of DDT, posted 2/23/00, 2:10 pm. Look at the values of the respective partitioning coefficients
  Kinetics of phenanthrene solubilization
Mathematical treatment of a batch type dissolution experiment for a PAH compound. Here we determine the mass transfer rate as well as the maximum soluble phenanthrene concentration. Posted 12/8/00, 2 pm
 
PDF version of the file above, posted 12/11/00, 9:20 am
  multiple segment reservoir problem
simple problem showing the effect of a sediment layer in a steady state problem posted 2/6/00
  same problem as above - PDF version
  Coliform variation during/after a runoff event 
multiple segment solution of coliform variation in a small cove during and after a runoff event. Posted 2/6/00
Treatment of coliform discharges required to meet permit limits
posted 2/22/00, 3:30 pm, principle of superposition applied to coliforms in an estuary, some discussion of dieoff coefficient
  DO profile resulting from nitrification
posted 6:45 am 2/22/00 A standard DO profile problem only the oxygen is used for nitrification instead of CBOD oxidation.
  parathion volatilization in a river
good application of the 2 film theory of  gas transfer
posted 10:00 am 2/9/00
  Prob 10-5 Chapra ; diffusion thru sediments
Good diffusion problem. I try to explore the similarity between the analytical solution used in the problem and the equation for a normal curve
posted 1/23/00 10:45 am
Euler's explicit method used to compute P concentrations in a lake 
A simple example showing how the explicit method can be used for environmentally related problems. posted 2/21/00, 9 am
Dissolved oxygen concentrations around Bogata, Columbia
calculation of DO concentration with changing temperature and elevation above MSL. Posted 2/11/00 NOON
finite difference solution for a mixed flow system
Development of a finite difference solution to the steady state advection dispersion equation, posted 1/25/00, 6:20 pm. Also listed in derivation section below. The resulting set of linear equations is solved by matrix inversion. This is inefficient because if you change the number of segments the matrices have to be manually reformulated.
Finite difference solution of mixed flow reactor using tridag
I think this is a pretty neat file. Because the resulting matrices are tridiagonal I used the "tridag" algorithm to solve the set of linear equations. This allows the user to specify or change the number of segments in the solution without manually reformulating the matrices. Tridag does it automatically.  Saves much work. I made this a PDF file because you can't implement the tridag algorithm unless you have the numerical methods pack. Posted 1/26/00, 9am
A relatively simple kinetics problem using data from Jerald Schnoor's contaminant transport text.
TCE diffusion from a lake, posted 8/19/01, 12:15 pm
Vapam, a soil fumigant, spill in the Sacremento River, posted 8/31/01, 11:15 am
Analytical solutions to transport equations used. Good use of stoichiometry too. From Fechner-Levy 2nd edition. A pdf file.
A gas transfer problem, posted 12/19/01, 9:45 am. From Stumm and Morgan, 3rd edition
Rate constant determination for Fe(II) oxidation using the method of excess. Posted 1/5/02, 10 am. From Weber and DiGiano

Laplace Transform solution of CMSTR ODE

I used Laplace Transforms to solve the mass balance ODE with constant loading and a first order reaction term.  I haven't used transforms in a while, pretty slick.  You get somewhat of an all purpose solution, posted 1/26/05, 8:20 am
A General Discussion of sinusoidal inputs as part of an equation  A general discussion of the use of sinusoidal terms to describe periodic processes, oriented toward environmental types, posed 7/1/07, 3:15 pm
Biochemical Calculations A neat problem from an earlier version of the well known Metcalf and Eddy text for waste treatment, illustrates the combined use of stoichiometry, lab results , and kinetic equations for solving activated sludge problems.  posted 1/18/09, 1:50 pm
Chick Watson Disinfection Model Fits Data to the Chick Watson Disinfection Model and Determines the coefficient of specific lethality, posted 1/18/09, 2:20 pm

 More contaminant transport type problems can be found in the chemistry section
 
LECTURE NOTES, DISCUSSIONS,  DERIVATIONS FOR CONTAMIANT TRANSPORT

Derivation of advection equation with reaction
A mass balance on a cube CV in space, reaction assumed to occur. A PDF file

  derivation of oxygen usage model, batch system, no reaeration
A simplified DO model for a batch system - a useful place to start - some discussion of parameters
posted 1:40 pm 2/11/00

  A discussion of the S-F oxygen sag equation - A simple problem used to develop the Streeter Phelps equation, some discussion of the reaeration coefficient and the solution's sensitivity to it.
posted 2/14/00, 7:30 am

Stagnant 2 film model for phase exchange
A derivation of the basic model and a discussion of its implications, PDF file

  A Derivation of the mean velocity gradient, G

  Development of finite difference solution to advection dispersion equation
Although this document contains an example problem, it is primarily a derivation

  Same file as above only in PDF format.   Same file as the one above, develops a simple finite difference     solution to the steady state advection, dispersion equation. posted 11/26/00, 8 am

  Lake - Instantaneous spill - The derivation of the analytical solution for an instantaneous spill into a lake

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                                          WATER RESOURCES I and II
Water Resources II is a computer oriented class taught at La. Tech. We make use of existing software packages from Haestad Methods and the Army Corps of Engineers (HEC-RAS, HEC-HMS) coupled with Mathcad to examine pipe networks, gravity drainage systems and hydrologic modeling. Students are taught open channel hydraulics as they are exposed to HEC-RAS.

Even though we have the HEC programs available, I like using Mathcad for much of the hydrology and hydraulics calculations because the mathematic manipulations required are input by and are visible to the student.

Mathcad is an excellent tool for carrying out UH construction (Snyder, SCS) and subsequent convolution with excess rainfall distributions. Minimizes tedious hand calculations.

Link to USACOE Hydrologic engineering center    http://www.hec.usace.army.mil/

Development of gradually varied flow equations   - Includes a qualitative discussion water surface profiles.

Gradually Varying Water Surface Profiles - PDF file

  2-6_unit_hydrograph_construction.mcd - Simple problem demonstrating some Mathcad techniques while developing a unit hydrograph for a gaged basin, posted 3/24/01, 8:30 am

  Modeling_IDF_curves.mcd - Mathematically modeling an intensity-duration-frequency curve using lsolve to evaluate the required parameters. Taken from McCuen's hydrology text, 2nd edition, posted 6/15/01 4 pm.

  Snyders_synthetic_unit_hydrograph.mcd - Using Mathcad to construct and verify the volume of a unit hydrograph, uses a linear spline to replace straight line segments with a smooth curve. I then integrate the spline to check that the volume is 1 area-inch. Adjustments to recession leg points can be made, if needed. Posted 10/11/01, 3:30 pm

  detention_basin_with_weir.mcd - This file explores the use of detention basins controlled by weirs loctated at the basin surface, the trade-off between plan area of the lake and the effect on the inflow hydrograph. posted 10/30/2001, 8:45 am

  example_prob_SCS_handbook.mcd - This file is a rather comprehensive example problem illustrating how to use the SCS method and convolution to develop a DRH for a 6-hour rainfall event. Posted 11/5/01, 2:20 pm

  SCS_dimensionless_unit_hydrograph_convolved_with_rain.mcd - This file is similar to the one above. An SCS UH is developed, excess rainfall is computed based on the UH curve number and the DRH is computed. Finally a mass balance check is performed. posted 11/12/01, 11 am

A file from Katrina   - I got this file from one of my former students Rel Gray) who works for a consulting firm here.  He developed it to size drainage systems for temporary housing sites for victims of Katrina and Rita (hurricanes 2005).  The firm is Hunt Guillot and Associates of Ruston, Louisiana.  Posted 10/29/05 3:30 pm.

  convolution_using_spline_to_pick_points_in_time .mcd - This is a comprehensive DRO problem. An SCS UH is developed first, then convolved with a rainfall hyetograph. An interesting wrinkle here is that, in order to get the same time interval for the UH readings as the rainfall hyetograph values prior to convolution, I use the interp(cspline) function to choose interpolated UH flows at 30 minute intervals, this is much faster than doing it manually. The technique was actually conceived by my students (and I thought they were asleep !)  Posted 5/3/02, 2:05 pm

Rainfall_IDF_curves.mcd - A neat little file I downloaded.  Originally developed (I assume) by Roger Hickman at the Texas Railroad Commission.  I added some explanation to try to make more usuable by undergraduates, posted 6/11/03, 3:15 p.m.

A discussion of Infiltration - This is a basic discussion of infiltration theory and a simple problem involving the Horton model for estimating excess precipitation.  In the file I embed an Excel spreadsheet and read data from it.  I like using Excel spreadsheets because data columns can be labeled.   Looks better than  a vector or matrix. Posted 1/15/05, 9:30 am

Times of Concentration - This is a problem from Gupta's Hydrology Text.  I added a few additional equations for computing the time of concentration, summarized the results in an Excel spreadsheet embedded in the file as a component, and then computed the peak flow using the largest and smallest values.  I used a solve block for the methods requiring an iterative solution for tc and the rainfall intensity, i.  Students are usually surprised at the size of the peak flow rate. Posted 2/7/04, 5 pm

The Phi Index - This example comes from Bedient, 3rd edition.  It works well using conditional statements to compute the incremental volumes of runoff for various phi values, posted 7/27/04, 7:50 am.  This is a pdf file.

Muskingum Channel Routing  -  This problem is based on one in Bedient and Huber.   In the problem the routing coefficient K is determined from data, then the the outflow hyrograph is plotted using several values of the weighting variable x and compared to the actual outflow hydrograph.  Posted 9/29/04,  2:45 pm


A straight forward Uniform flow Problem - A straight forward uniform flow problem.

  Ebook/Prob4-2_Uniform_Flow.PDF - Same file PDF format

  Direct_Manning_equation_solver.mcd - Direct solution of Manning's equation for pipes partially full,     posted 3/19/01, 9:30 am. I used global definitions here so the user can change inputs and see the results without having to page back and forth.

circular_pipe_partially_full.mcd  -  This file also illustrates a couple of ways of obtaining the required pipe diameter for specified flow properties
One procedure employs a graphical approach, the other a solve block, posted 6/13/04, 2:30 pm



Uniform Flow Problem Chap 4 problem 1- Another simple uniform flow problem.

  Haested_text_chap_1_prob4.PDF - PDF version of the file above



  Chow_3-7_specific_energy.mcd A proof and an example; specific energy at a critical section.

  Chow_3-7_specific_energy.PDF - PDF version


  prob_2-15_channel_transition.mcd - An examination of specific energy and channel transitions.

  prob_2-15_channel_transition.PDF - PDF vsersion


  Prob 1-2 Henderson surge in stream.mcd - This is a cross between an open channel flow problem and a dynamics problem. It involves motion relative to 2 different coordinate systems (observers)

  Prob_1-2_Henderson_surge_in_stream.PDF - PDF version


  specific_energy_diagram_and_discussion.mcd - The classic specific energy diagram, plots for specific flow values, and some discussion as to what it all means.

  specific_energy_diagram.PDF - PDF version



  Prob_5-6_canal_discharge.mcd - Problem considers the effect of downstream channel steepness on the discharge from a reservoir

  Prob_5-6_canal_discharge.PDF - Same file in pdf format

  pipe_network_example.mcd - A problem from Hydraulics of Pipeline Systems by Larock et al. Illustrates what can be done using Mathcad. Posted 10-7-00, 8:30 am



  Larock_pg_66_7_pipe_network.mcd - A network problem showing how to deal with multiple reservoirs, a pump and a pressure reducing valve (PRV). Makes use of the Mathcad version of the file below to develop the equation of the pump curve. Posted 10/22/00, 12:20 pm

  Larock_pg_66-7_pipe_network_vector_solution.mcd - This is EXACTLY the same problem as the one above only I have used vector notation where possible to reduce the amount of typing. Posted 10/26/00, 4:20 pm

  Pipe_Network_Analysis_12-6-1-b_Mays.mcd - A simple network problem from the Water Resources text by Mays posted 5/13/01, 5:45 pm

Problem 4.5.7 Mays - An overspecified problem  -  This an example of an overspecified problem.  Even so, equations can be written and the solution values provided obtained.  Its a good example of why one should never blindly accept results from a computer, even using Mathcad.  posted 3/28/05, 7:45 am.



developing_a_pump_characteristic_equation.mcd   A procedure for developing the equation of a pump curve from actual pump curve data. Also, an example problem showing how to solve a simple network containing a pump. Finally, a caution about using such techniques. posted 4/12/02 12:05 pm

  developing_a_pump_characteristic_Gould_12JMC.mcd Another pump characteristic problem, similar to the one above...with the same cautions. Posted 5/12/02, 6:10 pm

  8-130_3_reservoir_problem.mcd A standard 3 reservoir problem along with some discussion regarding the details of solving such problems using computer software. Posted 10-9-00, 11:15 am.

  A simple detention basin simulation - Here is a simple detention basin simulation algorithm. Basin simulation is based on the principle of conservation of mass. Most textbooks provide only graphical procedures and, in my judgement, the connection between conservation of mass and the actual procedure gets lost in the details of tabulation. posted 11/10/00, 3 pm.

Determining the operating point of a Centrifugal pump   -  This file illustrates how to detrmine the operating pointt, brake hp and efficiency of a centrifugal pump.  It is also a nice use of an Excel component inside a Mathcad file.  Posted 3/11/06

NPSH for a suction lift pump   -  This problem illustrates the concept of Net Positive Suction Head, NPSH, and how it is obtained.  This quantity is a determining factor in how far above the liquid level a suction lift pump can be placed, Posted 3/19/05, 7:35 am.

Mays 9-1-1 Level Pool.mcd   -  Level pool reservoir routing procedure.  I splined data for the storage - outflow curve to produce a continuous function, posted 5/12/05, 8 am  

  Convex_channel_routing_2_reaches.mcd - Uses the Convex procedure to route a hydrograph through 2 reaches, posted 7/2/01, 5:30 pm

Modified Att-Kin channel routing  - Some explanation of and an example problem (Example 10-4 McCuen) showing the use of the Modified Att Kin routing procedure.  Posted 10/10/04, 5:30 pm

  SCS_UH_with_convolution_using_D_as_the_time_increment.mcd - First we construct an SCS unit hydrograph. Then we convolve it with an excess rainfall hyetograph to obtain the DRH, posted 11/2/01, 3:50 pm

  5-19_Wildcat_Creek.mcd   - Assessing the fit of hydrologic data to a normal distribution. Because I have Mathcad statistical functions I did not need to use normal probability paper. I compared the data directly to a cumulative normal distribution using the mean and standard deviation of the data. Posted 3/18/02 10:10 am

  7-29_rational_method_pre_and_post_development.mcd - A pretty straightforward problem using the Rational Method to illustrate the increase in maximum flow rate as a result of basin development. Posted 4/7/02, 4:45 pm

Parallel pumps - A relatively simple parallel pump problem from Gupta's text.  I use splines to develop the curves from data given in the problem. Posted 5/12/04, 7:45 am.

Clark (time-area) UH procedure    Procedure for developing a UH using the "time-area" a.k.a "Clark procedure", posted 9/13/04, 11:45 am

Storage-Indication routing Procedure  -  A Mathcad / Excel file illustrating the storage-indication reservoir routing procedure.  I have commented the Excel columns, telling where the values came from., Posted 10/22/04, 5:15 pm


Computer output from Haestad Software
The files below are in PDF format. They give an idea as to what can be obtained from the academic version of the "Flowmaster" software from Haestad. Reference: Computer Applications in Hydraulic Engineering , 3rd Edition, Haestad Methods, CD included. I found this to be quite cost effective for students, compared to the professional versions.

Haestad_rating_curve_problem_1-5.PDF   Flowmaster output

Haestad_Detailed_Report_prob_1-5.PDF   Flowmaster output.  I used the "notes" window to write in the problem statement. It's at the bottom of the page.


Mathcad/Visio/Hec-ras problems

  Chow_9-8_water_surface_profile.mcd - Here I used Visio, a low end CAD package, to do the initial drawing. I used Mathcad to do some preliminary calculations. Then I used the current version of the Army corps of engineers open channel flow code, hec-ras version 2.2, to compute the water surface profiles. I then cut and pasted the graphical hec ras output into the Mathcad file. Note that I used the wrong channel width in the problem and had to revise the initial conditions (unrealistically). All of these packages are windows based, quite easy to use, and make it very easy to be quite productive and produce highly useful results.  Imagine how much work this problem would be to do by hand !

  Chow_9-8_water_surface_profile.PDF - PDF version of the file

A HEC-RAS - MATHCAD-VISIO file -  This file was created by cutting out parts of HEC-RAS output and editing them using Visio primarily but also Mathcad.  The final document was created in Mathcad.  HEC-RAS output can be "dismantled" in Visio and edited at a very fundamental level. Somewhat labor intensive but produces  useful prentation documents as well as useful teaching documents., posted 11/1/04 10:40 am

    Mathcad/HEC-HMS Problems

  Lake Norman Watershed model Lake Norman watershed problem taken from Akan and Houghtalen.  Here Mathcad is used to process and plot the out put from  HEC-HMS.
  Posted 10-18-04,  8:10 am

HEC-VISIO Problems

Effect of Bridge on Channel Backwater  (This is a pdf file)   I have taken the output from HEC-RAS, put it in Visio, "ungrouped" and edited each plot, then "regrouped" each plot.  This makes for better looking plots.  I also changed/ added to the plot titles and added text.  Posted as a pdf file  11/24/04, 1:25 pm

Subcritical-supercritical HEC-RAS/Visio water surface profile   - (pdf file)  Several plots showing a water surface profile changing from subcritical to supercrtitcal as the channel slope increases.   HEC - RAS error messages are also shown and discussed.  The HEC-RAS plots were post-processed using Visio.  Posted 11/30/04.




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DYNAMICS - MEMT 312
COORDINATE SYSTEMS
normal tangential coordinate system
posted 9am 3/8/00
Radial Transverse coordinate system
posted 9:45 am 3/8/00
PARTICLE KINEMATICS
Particle kinematics
A simple little problem requiring the chain rule. Posted 3/26/00, 10:20 am prob. 11-16 B&J
  PDF version of particle kinematics problem
prob 11-16 B&J
  falling particle with resistance 
 Prob. 11-21 B&J. I first published my version of this problem back in the early 90s' as part of an ASEE article. I've been working on it since, trying to develop an understandable study sheet to illustrate the usefulness of Mathcad for doing dynamics. Posted 2/27/00, 6:50 am
Falling Particle with Resistance - PDF version

Numerical solution to the classic trajectory problem
Turns out its not as easy to hit a target as it looks, posted 3/6/00, 2:45 pm
PDF version of the previous file, posted 7:50 am, 5/8/00
  Vibrating Particle - A dynamics Problem
Prob 11-85 B&J. An example of what can be gleaned from a simple little dynamics problem with MathCad
Particle trajectory problem - accelerating and retarding force used
Problem demonstrates the versatility of a well chosen acceleration term, posted 6:45 am 3/16

 Basic x - v - t problem uses data and splines
Basic problem illustrating relationship between acceleration, velocity and position.  Uses data and numerical techniques,  posted 5/24/05, 8 am
piston moving through oil
2 versions given, involves integrating the ODE for acceleration, posted 3/15/00 4:30 pm
Car Crash with Data Determining the speed of a car from crash test data. I like problems with data, posted 7/7/07 4:05 pm
Space Shuttle Re-entry Kinematics applied to space shuttle re-entry posted 8/12/08, 7:50 am


Angular Momentum of a System of Particles
Inextensible cord problem Posted 9/4/08 4:15 pm
LINEAR MOMENTUM
conservation of linear momentum
An examination of the effect of an impulsive force on the velocity of an engine/flatcat, posted 3/28/00, 10:05 am
Another simple momentum problem
3-196 M&K, simple but interesting, at least to me, posted 3/29/00, 8:50 am, A truck drives along a barge initially at rest in the water. Which way does the barge move and what's the name of the guy driving the truck ?
Analysis of a car crash
conservation of momentum used to find the initial speed of a car - posted 4/13/00 2:20 pm, 14-19 B&J 6th edition
  PDF version of car crash problem
14-19 B&J 6th edition posted 6:45 am 5/9/00
PDF file - M&K 3-196 - linear momentum
linear momentum 3-196 M&K,posted 3/29/00 3:50 pm
Linear Momentum with collision A neat little problem illustrating conservation of linear momentum with energy loss, posted 7/28/07, 4:10 pm


WORK ENERGY
  file:///E|/public_html/Ebook/Bullet.mcd
Compute the work done firing a bullet - problem uses data and spline functions for numerical integration - A good example of integrating numerical mathematics into dynamics.
  Analysis of ship fenders
Requires some judgement in dealing with nonlinear materials, solution to MEMT 312 extra credit problem, posted 4/4/00, 1 pm
Examination of a pile driver
posted 3/30/00, 3:20 pm
  A simple problem combining thermodynamics and dynamics
Combines ideal gas and definition of work, posted 11/26/00, 11:30 am
Blocks released from rest I just thought this was pretty neat problem, posted 10/16/05, 8 am
Truck with Load on a Slope Nice, straightforward problem.  I also show the effect of the slope on required stopping distance, 12/20/05, 3:20 pm
SYSTEMS OF PARTICLES
characteristics of a system of particles
problem shows the convenience of working directly with vectors in Mathcad, posted 7:10 am 3/16/00
  Alpha particle - oxygen nuclei collision
good use of i-j-k vector notation, posted 4/13/00, 2:20 pm
14-12%20car%20accident.mcd A really neat application of linear momentum to accident reconstruction, posted 11/8/05, 5:45 pm
 
Newton's Second Law
Meaning of zero gravity posted 7/25/07, 8:45 am, a simple problem exploring the weightlessness
  Connected Masses on a pulley
posted 7:14 am 3/1/2000, prob 12-19 B&J, 6th Ed. system 1
  PDF version - connected masses over a pulley
12-19 B&J
Ship movement
Newton's 2nd Law applied to ship motion to determine velocity
  Crate slides on truck bed
A discussion of the crates acceleration from different frames of reference, posted ? pm on 3/15/00, 3-11 M&K
  PDF version - crates slides on truck bed

A discussion of friction forces and frames of reference, posted 3/21/00, 6:30 am
Numerical Solution - Range of a Golf Ball A numerical solution based on Newton's 2nd Law applied to a golf ball, posted 9/4/05, 11:40 am
Edmund Fitzgerald A simple dynamics problem and the story of the Edmund Fitzgerald, no real connection but interesting all the same. Posted 11:15 am, 11/20/05
Car on circular track Explores the forces on a vehicle traveling in a circle. There is no centrifugal force, as such. Posted 7/1/07, 9:50 am
Tension in Wrecking Ball Cable Explores those factors affecting tension in wrecking ball cable, basic 2nd law problem in n-t axis. Posted 7-6-07, 9:40 am
 PLANE MOTION OF 2-D RIGID BODIES
USING VECTORS TO ANALYZE 2-D SYSTEMS
  Basic application of angular velocity and angular acceleration applied to a plate-bar assembly
Shows the value of the cross product and i,j,k notation for determining linear velocities in rotating systems, posted 4/15/00, 7:25 am, problem 15-10
  3 dimensional motion - rotating bar
A simple illustration of how to use vector algebra to solve a 3-D motion problem where visualization is difficult. A PDF file, posted 4/15/00, 11:20 am
angular velocity and acceleration of rotating disk A simple problem illustrating direction of the angular velocity and acceleration vector, posted July 4, 2007, 9:35 am
  Simple 2-dimensional motion
posted 4/24/00, 9:35 am, Visio drawings used
  SLIDER AND LINKAGE MOTION
  Classwork Problem - collar and member on vertical bar
The classwork problem for April 19. Posted 3:45 pm 4/19/00, pdf format , 15-32 B&J
  Classwork Problem April 19, 2000
The classwork problem for April 19. Posted 3:45 pm 4/19/00, Mathcad version 7, 15-32 B&J
  velocities and accelerations for a piston
posted 5/3/00, 7:45 am, lots of pictures
  collar and bar mechanism
posted 4/23/00 7:25 am, numerous drawings using Visio, saved as version 7 Mathcad
  problem using velocity center
posted 5/1/00, 4:10 pm, A discussion concerning how to locate a velocity center and what to do with it when you find it !
2-dimensional plane motion
  Web_site_dynamics/Sample_problem_vehicle_motion.mcd
Simple 2-dimensional plane motion problem
  Web_site_dynamics/4-13_M_and_K_angular_momentum_of_spheres.mcd angular momentum of system relative to inertial coordinate system, uses vector algebra, posted 4/18/00, 2 pm
  Web_site_dynamics/16-1_board_in_back_of_pickup.mcd
translation
  Web_site_dynamics/16-55_B&J_rolling_sprocket_wheel.mcd
Make sure of your vantage point when thinking about acceleration
  Web_site_dynamics/16-55_B&J_rolling_sprocket.PDF
PDF version problem above
  Web_site_dynamics/16-3_rod_in_slots.mcd
Pretty straightforward
  Web_site_dynamics/16-3_rod_in_slots.PDF
PDF version of problem above
  Web_site_dynamics/17-3_rotating_element.mcd
work energy
  Web_site_dynamics/17-3_rotating_element.PDF
PDF version of problem above
  Web_site_dynamics/P17-1_rotor_rotation.mcd
simple work energy problem extended a bit with plots
  Web_site_dynamics/P17-1_rotor_rotation.PDF
PDF version of problem above
  Web_site_dynamics/17-12_and_13_brake_pedal_assembly.mcd
A neat braking assembly problem, posted 5/16/2000
  Web_site_dynamics/17-12_and_13_brake_pedal.PDF
PDF version of problem above, posted 5/16/2000
  Web_site_dynamics/16-13_P-K_rotating_element.mcd Determining the velocity and acceleration of a point on a rotating element. Vector algebra used, posted 11:30 am 8/14/00
Notes on the Cross Product In this file I try to illustrate the usefulness of the cross product as a tool for determining the linear velocity of a point on a rotating system, posted 7/6/07, 11:05 am
3-D Rotation - angular and linear velocities A rotating cyliner.  I use the vector product to compute the linear velocity of a point on the cylinder.  Much explanation and many schematics.  The cross product is a valuble tool for these types of problems because they are not easily visualized and one is forced to rely on the vector algebra. posted 6/4/06, 10:15 am
2-D Rigid Body Rotation 2-D rigid body rotation , makes use of relative motion and vector algebra, not easily visualized,  posted 7/11/07, 3:10 pm
Torque produced by an operating motor How does a motor on springs react when it is operating and producing power ?  Posted 8/19/07, 3:50 pm
Work-energy for a 2-D rigid system Work energy applied to solve for the velocity of a wheel attached to a spring, posted 8/16/09, 12:17 pm
Rigid Body rotation A beam being lifted by two cables, posted 8/16/09, 4:00 pm
SUV rollover
Conservation of angular momentum of an SUV in a rollover, posted 8/16/09, 4:10 pm

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