Problems with unsteady transonic solver

Frank

Hello Folks, I'm currently trying to write an ADI scheme (essentially repeating the work of Ballhaus and Goorjian in their LTRAN2 code) to solve the low frequency transonic small disturbance equation. I'm having great difficulty in getting any useful results out of my current efforts. I have done everything the original 2 papers suggest but have a load of garbage results coming out.

Has anyone else tried this scheme and, if so, could you please point me in the direction of any suitable reading material on the subject?

I'd be very grateful to anyone that can help, Frank