numerical investigation of the unstart suppression in a supersonic air intake

the starting behavior of a supersonic axisymmetric mixed compression air intake was numerically investigated. the code solves reynolds-averaged navier–stokes equations using an explicit finite volume method in a structured grid by the roe flux difference splitting scheme. further, it uses the baldwin–lomax algebraic model to compute the turbulent viscosity coefficient. the correct method of surveying the intake starting problem and effects of several geometrical parameters such as: intake throat area, cowl lip roundness and spike surface curvature upstream of the throat on the starting and performance of the intake were studied. results showed that correct combinations of the mentioned parameters can suppress the intake unstart problem and in addition can prevent the reduction of the intake efficiency.