Energy Addition–Based Virtual Cowl for Performance Enhancement of Scramjet Intake

Abstract

Energy addition has been considered a means to improve the performance of supersonic inlets. The energy addition to supersonic inlets can be considered as a virtual cowl, which can be implemented during off-design conditions to essentially emulate the shock-on-lip (SOL) condition obtained at the design point. The primary purpose of this work is to increase the mass capture and the pressure recovery and reduce flow distortion at the exit of the isolator section by finding the optimum location and energy required to enhance the performance of the intake section. Parameters like magnitude and location of energy addition were examined. The performance was assessed using mass capture, total pressure recovery, static-pressure rise, and flow distortion. The effects of shock reflections at the exit and the shifting of separation zones due to energy addition have also been understood and discussed. An energy addition of 0.2 MW/m was found to be most suitable at a region that is near the cowl leading edge. Moving below or far above the cowl line was found to decrease the performance. The improvement in mass capture with suitable parameters can be up to 15%.