What are the three similar cases for examining Laplace's Equation boundaries?

  • Context: Graduate 
  • Thread starter Thread starter LHS
  • Start date Start date
  • Tags Tags
    Laplace's equation
Click For Summary

Discussion Overview

The discussion revolves around identifying three similar cases for examining Laplace's Equation boundaries, particularly in the context of specific rectangular domains. Participants explore different boundary conditions and expressions related to the temperature distribution T(x,y) within these domains.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant suggests examining the cases 0
  • Another participant proposes that the three cases could involve the same square but with different sides having T = 1.
  • One participant mentions obtaining complicated expressions after working through the new cases and questions the validity of setting x=y=pi/2.
  • A participant shares a complex expression for T(pi/2, pi/2) derived from one of the new cases, indicating uncertainty about using LaTeX for formatting.
  • There is a suggestion to consider the sum of all four solutions and its implications for the overall solution to the boundary conditions.
  • Participants discuss whether adding the solutions results in a uniform temperature distribution across the boundaries, with some confusion about the implications of this on the geometry of the problem.
  • One participant confirms that if T satisfies Laplace's equation and is constant on the boundary, then T must be constant throughout the domain.

Areas of Agreement / Disagreement

Participants express various viewpoints on the cases to examine and the implications of their findings, indicating that multiple competing views remain and the discussion is not resolved.

Contextual Notes

There are limitations in the clarity of the expressions derived and the assumptions made regarding boundary conditions. Some mathematical steps remain unresolved, and the scope of the discussion is focused on specific cases without reaching a consensus.

LHS
Messages
37
Reaction score
0
Can anyone help me think of the three similar cases I need to examine, I was thinking 0<x<pi/2 0<y<pi/2, 0<x<pi 0<y<pi/2, 0<x<pi/2 0<y<pi, with the same boundaries as those parts of the original square, but it doesn't really work for me, any help would be greatly appreciated!

[PLAIN]http://img145.imageshack.us/img145/5541/77950426.png
 
Last edited by a moderator:
Physics news on Phys.org
Welcome to PF!

Hi LHS! Welcome to PF! :smile:

(have a pi: π :wink:)
LHS said:
Can anyone help me think of the three similar cases I need to examine …

Well, the obvious three cases are for the same square but with a different side having T = 1 :rolleyes:
 
Ah thank you! that certainly makes sense, I seem to get very complicated expressions after I work those 3 new cases out.. I assume set x=y=pi/2 and equate? Doesn't seem to be happening unfortunately!
 
Hi LHS! :smile:

What are your other three expressions for T(x,y)?
 
oh hold on … because it was 3 days ago, i'd forgotten what this question was all about :biggrin:

start again …

if you add all four solutions, what is that the solution of? :wink:
 
If you add all four solutions do you get the solution to T=1 on all sides, e.g.
So it becomes a 1x1x1 cube?

4T(pi/2,pi/2)=1
=> T(pi/2,pi/2)=1/4?
 
LHS said:
If you add all four solutions do you get the solution to T=1 on all sides,

yes! :smile:
e.g.
So it becomes a 1x1x1 cube?

cube? :confused:
 
ergh.. sorry, that was me being an idoit. I was saying the distribution of T, would the surface be flat? at T(x,y)=1 for 0<x,y<pi, so you can say 4*T(pi/2,pi/2)=1
 
  • #10
Yup! :smile:

If T satisfies Laplace's equation, and is constant on the boundary, then it's constant.
 
  • #11
Brilliant! thank you very much for helping me with this.
 

Similar threads

  • · Replies 22 ·
Replies
22
Views
4K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 33 ·
2
Replies
33
Views
5K
Replies
3
Views
3K
  • · Replies 16 ·
Replies
16
Views
3K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K