Study of Buzz Surge for Supersonic Air Intake

Abstract

The project provides study of instability which occurs when supersonic inlet operation at off design conditions (flight condition and engine operation condition).When the inlet operate near to critical regime, the stability interrupted by transient process which occur due to reduce of mass flow required by the engine and boundary layer interaction with shock system. This phenomenon occurs due to flight condition and it is known as buzz. Also when mass flow store inside inlet exceed than mass demand by the engine, the normal shock will expelled out of inlet. This phenomenon occurs due to (engine operation condition) and it is known as surge. For an on-design condition, the total pressure recovery is maximized according to the optimization criterion, and the dimensions of the inlet in terms of ratios to the engine face diameter are calculated. The optimization criterion is defined such that in a system of (n-1) oblique shocks and one normal shock in two dimensions, the maximum shock pressure recovery is obtained when the shocks are of equal strength. This project also provides a method to estimate the total pressure recovery for an off-design condition for the specified inlet configuration. For an off-design condition, conservative estimation of the total pressure recovery is given so that performance of the engine at the off-design condition can be estimated. Also the project includes the methods discovered to reduce and solve these phenomenons. This methods lead to match the mass flow demand of the engine, the second ramp angle is adjusted and the open/close schedule of a bypass door is determined