[Muneeb]

Hi everyone

I am Performing compressible flow analysis in a 30 degree sector of jet engine afterburner.

Details:
Steady state
Flow: Compressible
Turbulence Model: K,E 2 eqn with realizable
BCs: Pressure inlet conditions, pressure Far field condition (at extended domain)
Mesh Size: 5 Million elements (Hexa + Tetrahedral)
Solver: SIMPLE
Mach Number: 0.1 (used in pressure far field Boundary condition)

The solution is easily converged without Extended domain (Extended domain is modeled after Converging diverging duct having pressure far field conditions).

However With extended domain, there comes warning 'Turbulence Viscosity ratio limited to 1e5 in xxxx cells'. This high value of turbulence viscosity ratio is indicated only in Extended domain. It is worthwhile to mention over here that extended domain is meshed with high quality hexahedral element (element size 10 mm). The said error creates problems in convergence. All is well without including extended computational domain. Refer Attached photograph please.

Please suggest the measures I should take in order to curb the issue of high turbulence viscosity in extended computational domain. Thanks in anticipation for your advices.

Regards