Flow Characteristics of a Mixed Compression Hypersonic Intake

The flow field in a two-dimensional hypersonic mixed-compression inlet in a freestream Mach numbers of M-infinity = 2.0, 3.0, and 5.0 are numerically solved to understand the effect of throat area variation. The exit area ratio variation is simulated by placing a plug insert at different axial locations at the exit of the model. The flow field is achieved computationally by solving the Reynolds Averaged Navier-Stokes equations in a finite volume framework. For each flow condition, the variation in shock structure is analyzed and the variation of the oblique shock wave angle with the mass flow rate is calculated theoretically and compared with the present CFD analysis. The variation in oblique shock angle is calculated in terms of the mass flow rate by considering the capture area and spillage flow through the inlet. The theoretical results suggest that the method can predict the inlet operating conditions at different freestream Mach numbers and area ratios. This method can quantify the reduction in mass flow rate due to the throttling effect by analyzing the flow field shock pattern. The effects of various important performance parameters such as free stream Mach number, total pressure recovery, and mass flow ratio were then numerically investigated. As the Mach number is increased, the total pressure recovery is reduced, but the maximum value of the mass flow rate is increased. The analysis is also focused on the effect of throat area variation on performance parameters at each Mach number. The characteristic curve of the inlet is then obtained for each free stream Mach number.