Hi guys,

I need some help with modelling an aircraft intake duct. It is pretty much a straight pipe - but I am having problems with the Boundary conditions.

I know the following: 1) Aircraft Speed (M=0.5-0.6) and Altitude - hence, we have Static Pressure and Total Pressure 2) Mass-flow the turbine requires.

The duct starts at the inlet lip and stops just upstream of the turbine.

What B.C. should I use?

You have extended the mesh,Right, so the inlet is far field BC

Well, I have extended the flow-field upstream of the lip, but I cannot use Pressure Far Field, since the PFF boundaries touch the walls of the duct

1- As far as I understand the geometry, You seem to be interested in the internal flow, but how about the intake geometry shape itself and its effects on the flow field (Intake Aerodynamics by J. Seddon and E.L. Goldsmith or Inlets for Supersonic Missiles by John J. Mahoney for more details). Why are you surprised by extending the mesh? is that a professional job or home work for your CFD class? 2- Could you please send an iges file of your geometry (or an image file) 3- You could read the tutorial on the flow around a wing section (your domain is just two of them) Hope that will help, good luck.

Hi Ahmed,

This was a first test case, and currently I have the duct imbedded into the fuselage to model it inlet lip and fuselage effects.

- The "duct inlet" condition will be determined by the external aero, and the outlet will be Pressure Outlet with Target mass-flow specified.

- This is for work, so I am not allowed to release any drawings...sorry...

Regards Riaan