Computation of the maximum flow rate of a perfect gas through a slit in a plane wall (Q1080736)

The steady flow of a perfect gas through a slit in a plane wall is studied. The pressure conditions are such that the flow is near its maximum rate, and the flow is transonic. The flow is assumed to have no shocks near the wall, and the equations are formulated in a potential- stream function-coordinate system. The coordinate system is then transformed, and the equations are solved with a finite-difference method using second order accurate, central differences all over the domain. The resulting nonlinear system is solved using Newton's method. By computing a certain characteristic it is determined when changes in the pressure no longer influences the inflow side. This is used to estimate the maximum flow rate. The numerical computations were performed on the vector computers CYBER 203 and CYBER 205.