Hi, all
I'm testing mathematica for 30 days. I've several questions: the first one: Is here the right place to do that? If not, please tell me, where I can do that!
Actually I test PDE solutions ( transient heat conduction). Has anyone an idea, why the following PDE example from the Help Documentation works
NDSolve[{D[u[t, x], t] == D[u[t, x], x, x], u[0, x] == 0,
u[t, 0] == Sin[t], u[t, 5] == 0}, u, {t, 0,
10}, {x, 0, 5}]
while the following example ( I've changed one boundary condition- I hope, that was the only change- ) doesn't:
NDSolve[{D[u[t, x], t] == D[u[t, x], x, x], u[0, x] == 0,
u[t, 0] == Sin[ t], D[u[t, 5], x] == 0}, u, {t, 0, 10}, {x, 0,
5}]
what is my mistake?
hopefully, later on I want solve the following problem:
a one dimensional bar (constant heat conductivity, density, heat capacity) is heated ( or cooled) at one end with a given, time dependent fluidtemperature distribution (as a function or at discrete times with interpolation). The heat transfer coefficient is assumed to be constant.
The other end of the bar is assumed to be isolated( dT/dx=0)
After my first insights in mathematica examples, I think this could be done with mathematica and in an CDF document ( with or without mathematica?) with the following options:
changing the material coefficients ( perhaps from mathematica databases or a own one)
changing the given, time dependent fluidtemperature distribution
and, at top: changing the initial and the possible boundary conditions ( I've seen a comparable CDF document: beam deflection with different boundary conditions)
choosing between different solution presentations:
3D plot ( temperature distribution as function of space and time)
2d plot temperature vs bar length ( at different times)
table form temperature vs bar length ( at different times)
maybe, that this example is too complicated for a newbie?
but anyway, thank you so much for any help!
Peter
