Mass flow and Mach number boundary conditions for subsonic inflow and outflow boundary

This report describes the development and verification of an inflow and outflow mass flow boundary condition. In addition, an outflow Mach number boundary condition was implemented and tested. The main motivation behind the development of a mass flow boundary condition is a need to bridge the gap between the requirement of direct setting of mass flow as one of the most important parameter and the difficulty of indirect control of mass flow using static pressure outflow and total states inflow boundary conditions. The mass flow and Mach number boundary conditions were verified in low speed flow through a 2D channel with constant area and in high speed flow through the RAE M2129 S-duct with large separation. Attention was paid to the behavior of the mass flow boundary conditions in choked flow.