I am trying to write a code and would like to know what would be the appropriate numerical scheme to capture the flow from Supersonic to Subsonic. We are looking at Mach 3 to subsonic and a mixed external as well as internal flow. Dr N M Sudharsan

There is a wide range of length and time scales involved in the range of speeds that you are proposing to your program. A pressure coupled solver will do well in the transonic to supersonic speeds, but what about the incompressible range You would need a SIMPLE type solver I do not think you can cover the whole range with a single scheme, check the commercial solvers available, FLUENT and like, they provide different schemes Good Luck