Compressible flow problem
 

Hi to all,
I am simulating a compressible flow with Steam(Equilibirium) in CFX.My input BC's are,

Inlet Total Pressure = 0.05768 atm & T = 308.82 K (mass flow =111.17 kg/s)
Outlet Static Pressure = 0.05004 atm
Reference Pressure = 0 atm

Material: Steam Vapour (IAPWS table).

I started with water ideal gas and it is converged.When switching to steam it is not able start the calculation.
I tried different options and getting different warnings(Invalid number,Floating point, Over flow,High mach number,Table Clipping error and etc..)

Could anybody help me to solve this problem.

Thanks in Advance

IAPWS are always hard to converge.

You are using the ideal gas result as an initial condition? That will help a lot.

Also (the standard stuff for numerical instability): Improve mesh quality, double precision numerics, smaller time steps, start with low order advection (Upwinding).

Thanks Glenn for your reply.

1) After so many trials i managed to converge 2 cases (Total 5 different Pressure BC cases & Same mesh).But other cases reporting high Mach number and solver is failing.

2) How i can deal this high mach number warning...

As I said: Improve mesh quality, double precision numerics, smaller time steps, start with low order advection (Upwinding).