Non-uniqueness of transonic flow in an intake-type channel

Abstract

Abstract The two-dimensional turbulent airflow in a 9-degrees-bent channel is studied numerically. Inner surfaces of the top and bottom walls are parallel to each other upstream and downstream of the bend. The free stream is supersonic, whereas the flow is subsonic at the channel exit. Solutions of the Reynolds-averaged Navier-Stokes equations are obtained with a finite-volume solver using the Spalart-Allmaras and Shear Stress Transport k −! turbulence models. The solutions reveal a flow hysteresis and non-uniqueness in considerable bands of the free-stream Mach number, angle of attack, and exit pressure. At the endpoints of the bands, there are abrupt changes of the shock wave system. The non-uniqueness admits different losses of the total pressure, which may cause different trusts of an air breathing engine.