May 19, 2023 at 10:57 am
ricardo.pferreira
Subscriber

Hi Federico, Rob,

Thank you for your quick replies.

Regarding the DBNS, I've seen that when a fluid is compressible (Ma > 0.3) the DBNS should be used. However, I've also seen that both solvers can be used for subsonic/low supersonic flow regimes (here I'm having Ma=0.75 at the engine inlet, and 0.77 and 1 for the Bypass and Core outlets respectively). I was not able to reach any satisfatory results (nor convergence) using the setup described above, so I've changed it to the following setup:

  • Pressure-Based Solver (DBNS) with 2nd order for all equations
  • Compressible flow

Input parameters:

Material: Air

Density: ideal-gas

Viscosity: Sutherland

Model: Realizable k-epsilon (2 equ.) w/ Scalable Wall Functions

Operating Pressure: 0 Pa

Boundary conditions:

Engine Inlet: Pressure-outlet

Engine Outlet (Core): Mass-flow Inlet 

Engine Outlet (Bypass): Mass-flow Inlet 

Solution method: Coupled - Least square - 2nd order - Pseudo Time Method

Initialization method: Hybrid

Although I'm now having some satisfactory results, the exhaust contours are still higher than the expected, and I'm still getting reversed flow at engine inlets and some high residuals.

Thanks in advance!