Effects of extruded lobe-nozzle on fuel mixing of transverse air and fuel jets at supersonic flow

Abstract

Improving fuel mixing is a crucial step in increasing the flight speed of high-velocity vehicles. This study aims to investigate the importance of an extruded single lobe-nozzle in facilitating efficient fuel mixing inside the combustion chamber of a scramjet engine. Computational techniques are used to model compressible supersonic flow with transverse air and fuel jet released from the extruded nozzle in the combustion chamber. The study extensively analyzes the effects of injector types (2-lobe, 3-lobe, and 4-lobe) of the extruded injector on shock interaction and flow features of air and fuel jet behind the injectors. Due to the presence of the extruded nozzle, shock interactions are strengthened, and the vortex feature behind the nozzle is extended. Fuel penetration and mixing are fully discussed to obtain an efficient model for fuel injection in the combustion chamber. Additionally, the study discloses the influence of the height of the extruded lobe injector on fuel mixing. The results of our study indicate that the lobe injector improves fuel mixing more efficiently behind the nozzle, while a circular nozzle is efficient for fuel mixing far downstream of the injector.