Stephen

October 13, 2002 12:08 
Problem trying to use a backpressure
The geometry for my model is a that of a sudden expansion duct. I am only using air as my fluid. The airflow inlet has a Mach # of 2.5. I am trying to create a back pressure at the outlet to affect the upstream interaction. The backpressure simulates the injection of a gas normal to the flow. My problem is that if the outlet is locally supersonic then FLUENT extrapolates the pressure upstream and basically ignores the backpressure value given. I want to know what can I do to correct this problem so that the backpressure I gave gives the correct solution from other numerical results. Thanks.
