[Venkatraman Nagarajan]

Hello I am doing a thesis related to truncated aerospike nozzle.All I have to do is put the aerospike inside an enclosure and perform a flow simulation as per nozzle specifications.The enclosure is a rectangle and all of these is done in 2D.I am doing a compressible flow supersonic analysis. I am getting a perfect solution if I keep the bottom of the rectangle as a pressure outlet but I am not getting a good solution if I change the type of the left and right sides of the rectangle to pressure outlets in addition to having the bottom side as a pressure outlet.Should I use a far field approximation or do I keep changing the limits,urf and courant number?
In the attachment i want sides 1,2,3 to be pressure outlets.Thanks in advance.