Math 221

Numerical Solution of

Partial Differential Equations

Part I

Class meets Tuesdays, Thursdays, 3:30 PM to 4:45 PM in Phillips 301

Office hours: M-Th, 11:00 AM to 12:00 PM, (Phillips 307), e-mail appointment

[Motivation] [Objectives] [Syllabus] [Grading] [Texts] [Assignments] [Computing] [Projects] [Midterm] [Final]

 

Motivation

The physical world is described by a small set of laws. One of the most useful mathematical statements of these physical laws is in the form of partial differential equations (PDE's) describing local changes in physical parameters. Though it is usually straightforward to write down the particular PDE's that correspond to a given problem, finding a solution is much more difficult. For the vast majority of real-world problems approximate techniques must be used. One of the most productive approaches is to use a numerical approximation of the PDE's of interest. These techniques are used in studying chemical reactions, ecological models, astrophysical phenomena, aircraft design, financial models and in many other application domains.

 

Course Objectives

The development of numerical methods for PDE's and the ensuing theoretical development is within the province of applied mathematics. This course introduces the basic aspects of the discipline at the graduate level. At the end of the course the student should be able to understand the basic theory associated with solving each type of PDE encountered in practice, be adept at choosing methods appropriate for a specific application and be proficient in the computer solution of PDE's.

 

Syllabus

  • Basic equations of mathematical physics, other application domains

  • Minimal residual formulation

  • Numerical methods for ODE's

  • Linear advection diffusion equations

  • Parabolic equations

  • Hyperbolic equations

  • Equations of mixed type

  • Coupled PDE-ODE systems

 

Grading Policy

Grading shall be determined based on homework (HW, 48 points), supplementary reading (SR, 8 points), final project (FP, 16 points), midterm examination (ME, 14 points) and final examination (FE, 14 points). The number of points accumulated during classwork is mapped to a graduate grade as shown in the following table.

Clear Excellence

H

87-100 points

Entirely Satisfactory

P

70-86 points

Low Passing

L

50-69 points

Failed

F

0-49 points

 

Course Texts

One of the tenets of graduate study is the ability to critically examine multiple sources in order to verify theories and to enhance understanding. Lecture notes for the course shall be provided online in Postscript and PDF formats. These are meant to document the progress of material presented in class. It is expected and required that the student supplement the lecture notes with reading from other sources.

Lecture notes

Lecture
Date

Topic

Notes

Lecture
Date

Topic

Notes

1, 8/20

Overview of PDE's

 .ps .pdf

  10/10

Lab: advection

Lab3

2, 8/22

ODE/PDE problems

 .ps .pdf

15, 10/15

Modified equations

 .ps .pdf

3, 8/27

Weighted residual

 .ps .pdf

  10/17

(Fall break - no class)

4, 8/29

ODE IVP

 .ps .pdf

16, 10/22

Non-linear hyperbolic equations

 .ps .pdf

5, 9/3

ODE num. methods

 .ps .pdf

17, 10/24

Hyperbolic systems

 .ps .pdf

6, 9/5

Euler method analysis

 .ps .pdf

18, 10/29

Finite volume

 .ps .pdf

7, 9/10

Stability, consistency

 .ps .pdf

19, 10/31

Splitting methods

 .ps .pdf

8, 9/12

Bnd. Loc., convergence

 .ps .pdf

  11/5

Lab: Spectral differentiation

 

9, 9/17

Fourier analysis

 .ps .pdf

20, 11/7

Spectral methods

 .ps .pdf

10, 9/19

1D Heat eq. FDM's

 .ps .pdf

21, 11/12

Compact finite differences

 .ps .pdf

11, 9/24

2D Heat eq.

 .ps .pdf

22, 11/14

Finite element methods

 .ps .pdf

  9/26

Lab: Fourier space

 Lab2

 11/19

Lab: 2D Navier-Stokes equations

 

12, 10/1

Linear advection: characteristics

 .ps .pdf

23, 11/21

Finite element formulations

 .ps .pdf

13, 10/3

Basic advection methods

 .ps .pdf

24, 11/26

Ritz formulation example

 .ps .pdf

14, 10/8

Advection schemes: stability

 .ps .pdf

35, 12/3

Project presentations

 

General bibliography

The following texts serve as general background material. Students are encouraged to actively read from these texts material related to the current lecture. Homework and final examination questions from this material should be expected.

Finite Difference Schemes and Partial Differential Equations, John Strikwerda

Numerical Methods for Conservation Laws, Randall LeVeque

Finite Difference Schemes for Computational Fluid Dynamics, Phillip Colella & Gerry Puckett

Suggested reading for specific topics

Material specific to a certain topic shall be listed here as the course progresses. Generally the books or articles will be placed on reserve at the Mathematics Library in Phillips for the time period indicated

P.G. Garabedian, Partial Differential Equations, Chapter 1, The Method of Power Series. (17 pp.). On reserve: Aug. 22 - Aug. 29. Questions to ponder: (1) Consider the relevance and applicability of the methods used in the Cauchy-Kowalewski theorem to practical computations; (2) Try to find a biography of Sophia Kowalewski (also transcribed as Sonja Kovalevski) and place the Cauchy-Kowalewski theorem in historical context.

G. Dahlquist, Numerical Methods, Prentice-Hall, 1974, Sections 7.1 (Difference operators), 7.2 (Richardson extrapolation), Chapter 8 (Differential equations)

 

Assignments

Homework assignments

During the course, 6 homework assignments shall be given. Each homework shall contain 4 required topics and a bonus topic, each worth 2 points for a maximum of 10 points. The bonus topics are meant to allow for makeups of deductions on homework or examination grades. Homework assignments are given every second Tuesday and due two weeks thereafter. The purpose of the homework assignments is to achieve familiarity with the course material.

Date issued

Date due

Topic

Homework

Solution

8/26

9/9

Finite differences

.ps .pdf

9/9

9/30

Numerical methods for ODE's

.ps .pdf

.ps .pdf

9/30

10/14

Heat equation algorithms

.ps .pdf

.ps .pdf

10/14

10/28

Linear hyperbolic equations

.ps .pdf

.ps .pdf

10/28

11/11

Non-linear hyperbolic equations

.ps .pdf

.ps .pdf

.ps = Postscript File, .pdf = Portable Document File, .html = Web page, .nb = Mathematica notebook .m = Matlab m file .f90=Fortran 90 source file

Supplementary reading assignments

Two reading assignments shall be given, each graded with 4 points. The purpose of the reading assignments is to introduce students to the tasks involved in research work. Points are awarded to this end as follows:

  • 1 point for reading the assigned text (I'll ask a quick question);

  • 1 point for background research, i.e. placing the assigned text in the context of previous work for instance by reading the references from the assigned text;

  • 1 point for forward research, i.e. investigating the ramifications of the assigned text using tools such as the Science Citation Index ;

  • 1 point for working through some of the results from the assigned text,

Students can freely choose when they want to carry out their reading assignment, but beware the temptation of putting things off until the last week of the semester. A rack with suitable papers is available in my office. Duplicate reading assignments are not allowed. A short report on each reading assignment must be prepared and turned in before the end of the semester.

 

Computational work

It is essential that students acquire a basic familiarity with the process of developing and using scientific software. The homework assignments shall contain gradually more difficult problems that are intended to be solved using programs written by the students. The problems in the first homework assignments are small enough that they can solved using Matlab. Later problems are more computationally intensive and require writing programs in a compiler language such as C or Fortran.

Computer lab sessions

In order to aid proficiency in computer techniques a number of classes will be held in the computer lab (Phillips 324). Typically we will start from an initial file to be downloaded from this website and work through it.

9/4

Introduction to Mathematica, Finite differences

lab1.nb

 9/25

ODE stability

lab2.nb

10/9

Real, Fourier space behavior of common PDE's

lab3.m

10/23

lab4.m

11/20

Spectral method for Navier-Stokes equations

specaccuracy.m
lab5.m wavenumber.m

Final project topics

Project ideas. Some typical project ideas are shown below. You can choose one of these or just browse through to get some inspiration for a theme of your own choosing.

1. Antisound

2. Optimal placement of effluent pipes

3. Sound barrier

4. Target identification through sound

5. Target identification thorugh heat

6. Beach erosion

 

Final projects will be defended in my office Phillips 307 by appointment up to December 10, 2003.

 

Midterm examination preparation

The midterm examination will be held Thursday, October 30 from 3:30 PM to 4:45 PM in Phillips 301. The syllabus comprises course material up to and including finite difference methods for the heat equation.

Questions similar to those students can expect on the midterm examination. (Some of these are from examinations covering more material than what is required for the midterm)

1.pdf

2.pdf

 

Final examination preparation

The final examination will be held Saturday, December 13 from 4:00 PM to 6:00 PM in Phillips 301. The syllabus comprises course material from the hyperbolic PDE's to the end of the course.

 

Questions similar to those students can expect on the final examination. .ps .pdf

Solutions: .ps .pdf