Hi,

I have a basic flow simulation problem. I have set up a finite difference flow simulation program for fluid flow through a straight pipe (using 2D parabolic wave equation ut = uxx + uyy). I would like now to taper the pipe to a very small diameter. The same code does not give the correct behavior, before or after the taper region.

Has anyone out there encountered and/or solved this type of system? Thanks for your help!

What kind of behavior are you expecting? If you are actually simulating a fluid system, then you need an equation for v and one for p as well, and the inclusion of the pressure gradient in the momentum equations. If you are solving a model problem, then you need to determine what the behavior should be based on the solution to the model equation. More details on your issues would probably help people figure out how to answer your question.

FDTD is widely used in computational electromagnetic field.

this may mean nothing to you but there are some flutes and whistles with tapered shafts to effect air flow.