Learning Forum

[jainanup27]

Hi,

I am trying to use a Pressure Based (Steady State). I have a velocity inlet (103 m/s) and pressure Outlet (0 Pa) (Note that Operating Pressure is 860 Pa. My system operates at a total pressure of 860 Pa). Using this Boundary Conditions when I have a mesh size of 0.3 million cells my solution converges with no single error. However, when I increase the mesh size to 0.45 million cells, 0.65 million cells, 0.85 million cells, etc. I get the following error.

"reversed flow in 79 faces on pressure-outlet 15. Stabilizing pressure coupled to enhance linear solver robustness.

Stabilizing temperature to enhance linear solver robustness. Divergence detected in AMG solver: temperature limited to 1.000000e+00 in 383215 cells on zone 11 in domain 1. turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 225 cells 

Divergence detected in AMG solver: temperature

reversed flow in 85 faces on pressure-outlet 15. 

Divergence detected in AMG solver: temperature

Error at host: floating point exception"

 

With an increase in mesh size (except 0.3 million cells), the following line appears after every 2 iterations: "Stabilizing pressure coupled to enhance linear solver robustness" and then I have reversed flow on some faces for few iterations (sometimes not always) and then solution suddenly blows up with the AMG Divergence Error.

Can someone help?

Please find the attached image of my domain

 

[jainanup27]

Hi, 

Below are the details of the physics that I am using

Turbulence Model:  K-Omega SST

Fluid: Air (Incompressible Ideal gas)

Pressure-Velocity: Coupled Solver

BC : Inlet: 103m/s

Outlet: Pressure (0 pa) (Note: Operating Conditions: 860 Pa)

Wall: Stationary wall (Geometry)

Wall: Moving Wall (Fluid Domain) shown in the image attached in the post above

Hybrid Initialization

Thanks,

Anup