Problems I am facing:
1. Reverse flow at the outlet (I tried extending the domain, but to no avail.)
2. Maximum temperature/ pressure limited in....
3. Solution not converging, particularly the residual for continuity. Others also take a lot of iterations for converging
Kindly find the details of the set-up here:
1. Steady State, Density-based, Axis-symmetric
2. Spalart Allmaras Turbulence Model with energy eqn on
3. Air modeled as ideal gas with Sutherland model of viscosity
4. BCs: (i) Pressure inlet, Gauge Total Pressure = (NPR*101325 - 101325) ; Supersonic/ initial Gauge Pressure = 5 Pa less than the total pressure; Total Temperature = 300 K.
(ii) Pressure outlet, Gauge Pressure = 0 Pa, Total Temperature = 300 K
(iii) Temperature of 300 K applied at walls
(iv) Operating Pressure = 101325 Pa
Details regarding mesh:
Structured mesh with 2,52,958 cells.
Avg. element quality = 0.79571, Min. element quality = 0.28747
Avg. skewness = 1.2058e-002, Max skewness = 0.35188
Avg. aspect ratio = 2.0994, Max aspect ratio = 6.7975
Avg. orthogonality = 0.99705, Min orthogonality = 0.85175
Check your residuals, if they starts to oscillate after a certain amount of time, you might not have a steady state solution to this problem.
Non convergence means solution is not converging, firstly refine your mesh ,try decreasing relative tolerance of solver and increase the maximum no of iterations. Suppress the backflow conditions at outlet
Hope that could work
I would say, you should re-check your boundary conditions (in the software).. meanwhile, if you have a reversed flow in a JET flow simulation, that might be a normal phenomenon (if there is suction and re-blowing)
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