Compressible turbine blade simulation
 

Hi

I am trying to simulate a turbine blade film cooling by CFX. There is a cool flow injection from 2 row of cylindrical holes at leading edge region, one in pressure side and other on suction side. The following boundary conditions exist: Mainstream: Mach number=0.37 Total pressure=19650 N/m^2 Total temperature=303.15 K Main flow angle=43 deg

Coolant: Total pressure=21710 N/m^2 Total temperature=303.15 K

Mass flux ratio of coolant to mainstream=1.1

Blade exit: Static pressure=14640N/m^2 Isentropic exit Mach number=0.95

When I apply the above conditions and run, the following errors appear at each step and program diverges:

1) The maximum Mach number currently is 3.682E+00. If this message persists and you experience robustness problems, consider setting the expert parameter 'max continuity loops' to 2.

2)A wall has been placed at portion(s) of an INLET boundary condition (at 38.4% of the faces, 32.9% of the area)to prevent fluid from flowing out of the domain.The boundary condition name is: coolant. The fluid name is: Air Ideal Gas. If this situation persists, consider switching to an Opening type boundary condition instead.

I have changed 'max continuity loops' and boundary condition to opening but these errors exist yet. I'd be grateful if you help.

Re: Compressible turbine blade simulation
 

Hi,

Does the model run succesfully when you just run single phase, that is air only? It will have to run OK with air only before the multiphase version has a hope.

Glenn Horrocks

Re: Compressible turbine blade simulation
 

Hi Glenn

I have problem with single phase, only air! Could you please help? It is part of my thesis.

Regards

Re: Compressible turbine blade simulation
 

Hi,

Read the CFX documentation for initial help. There are sections on hints for obtaining convergence and a best practises guide for turbomachinery which should come in handy.

Glenn Horrocks

Re: Compressible turbine blade simulation
 

Hi amisa!

Qnet-CFD's best prctice guidelines for Turbomachinery(u can get it from cfd-online links) is very much handy to start with single phase T.M.simulations.