Trouble in solving stiff eq

September 18, 2003, 15:37

I have a system consisting of 2 PDE (resulting from continuity and momentum equations). The system has very large coefficients. The system seems to be stiff since the numerical solution changes with time step and spacing (very small time step requied for stability). It seems that to be difficult to get a solution independent of mesh size and time step.

It is highly appreciated if you let me know as you have the experience to deal with such system or know some good references.

T

September 18, 2003, 22:31

Have a look for VODE and CVODE on the internat - hese are two codes for solving stiff ODE systems in Fortran and C produced at the LLNL. You should be able to download them and use them for free.

Greg

September 19, 2003, 08:58

Thanks to Perkins. But is the code for ODE good for PDE?

T

September 18, 2003, 15:37	Trouble in solving stiff eq	#1
tang Guest Posts: n/a	I have a system consisting of 2 PDE (resulting from continuity and momentum equations). The system has very large coefficients. The system seems to be stiff since the numerical solution changes with time step and spacing (very small time step requied for stability). It seems that to be difficult to get a solution independent of mesh size and time step. It is highly appreciated if you let me know as you have the experience to deal with such system or know some good references. T

September 18, 2003, 22:31	Re: Trouble in solving stiff eq	#2
Greg Perkins Guest Posts: n/a	Have a look for VODE and CVODE on the internat - hese are two codes for solving stiff ODE systems in Fortran and C produced at the LLNL. You should be able to download them and use them for free. Greg

September 19, 2003, 08:58	ODE for PDE?	#3
tang Guest Posts: n/a	Thanks to Perkins. But is the code for ODE good for PDE? T

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