- #1
maistral
- 240
- 17
Hi. Been a while since I logged in here, I missed this place.
Anyway, I have a question (title). Is that even possible?
Say for example I have the standard heat equation (PDE) subject to the boundary conditions:
T(0,t) = To
T(∞,t) = Ti
And the initial condition:
T(0,t) = Ti
I am aware of how to solve this analytically. I would like to try solving it numerically - using finite difference methods. However, I have no idea how will I discretize something that is infinite...
What I did is assume x to be a gigantic value (which would become very unwieldy if my spatial step is something like 0.0001). Then, at the final spatial point, either I assume that the derivative is zero (because apparently if I compare it with the analytical solution by having t = a very large value, then run the numerical simulation for a very long time, both dependent values will become To) or just set the value to be equal to Ti (but I run at the difficulty of having the last point still equal to Ti at large time values).
So my question is: How is it possible to discretize infinite boundaries effectively? Thanks!
PS: I know that this is graduate-level math, but please talk to me in layman's language. I easily get inebriated if you guys bring out complex terms suddenly. Thanks.
Anyway, I have a question (title). Is that even possible?
Say for example I have the standard heat equation (PDE) subject to the boundary conditions:
T(0,t) = To
T(∞,t) = Ti
And the initial condition:
T(0,t) = Ti
I am aware of how to solve this analytically. I would like to try solving it numerically - using finite difference methods. However, I have no idea how will I discretize something that is infinite...
What I did is assume x to be a gigantic value (which would become very unwieldy if my spatial step is something like 0.0001). Then, at the final spatial point, either I assume that the derivative is zero (because apparently if I compare it with the analytical solution by having t = a very large value, then run the numerical simulation for a very long time, both dependent values will become To) or just set the value to be equal to Ti (but I run at the difficulty of having the last point still equal to Ti at large time values).
So my question is: How is it possible to discretize infinite boundaries effectively? Thanks!
PS: I know that this is graduate-level math, but please talk to me in layman's language. I easily get inebriated if you guys bring out complex terms suddenly. Thanks.