Finite Boundary Conditions
- To: mathgroup at smc.vnet.net
- Subject: [mg6956] Finite Boundary Conditions
- From: "Rick A. Sprague" <sprague at egr.msu.edu>
- Date: Wed, 30 Apr 1997 22:25:08 -0400 (EDT)
- Organization: Michigan State University College of Chemical Engineering
- Sender: owner-wri-mathgroup at wolfram.com
Hello,
I was trying to solve this differential equation for viscous flow through a
circular pipe:
D/Dr (-r m D/Dr v[r]) = A r
where
A,m - constant
r- radius
v - velocity
BC:
v'[0]=0 Symmetry
v[R]=0 No Slip
I get the following message and {} as a solution:
"Power::infy: Infinite expression 1/0 encountered."
MMA is having a problem solving for C[1] when r=0 - which I can understand.
v'[r]==-A r/ (2m) + C[1] / r
I could solve this equation by hand, but I was wondering how to make MMA
force a finite boundary condition. Actually, how does one generally submit
the BC "finite" to MMA?
Thanks,
Rick