Modeling & Numerical Analysis of Supersonic Combustor with Double Inclined Ramp-Cavity Fuel Injector

摘要

Sustaining the Supersonic Combustion in Scramjet engine is a very challenging topic of research nowadays. ‘Single-stage-to-orbit’ aerospace vehicles incorporating scramjet engine, is being contemplated to cut down space transportation costs. Propulsion and airframe unit integration, where the vehicle body adds to the thrust generating capacity of the engine besides providing aerodynamic lift, forms an integral part of the design philosophy. This Paper describes some challenges in the modeling of the Supersonic Combustor for proper mixing of air-fuel. Fuel Injectors are a critical component and their design has important effects for sustaining the flame in supersonic combustion as well as overall performance of the engine. Ramp injectors are considered to be a key feature to generate axial vortices. Generation of acoustic oscillations by the cavity injector is also considered to be a better candidate to achieve optimum mixing. Improvement in the performance of ramp and cavity injectors can be improved overall, by combining these injectors properly. Generation of turbulence and 3D flow field for better mixing and proper combustion relies on the combination of cavities and ramps. Ramps will improve the penetration of fuel in to the core and cavities will improve the flame holding characteristics. The ramp generated axial vortices can be utilized to scoop out the hot gases generated at cavities to improve the combustion efficiency. Thus Ramp and cavity combination shows promising characteristics for better scramjet combustor performance. Instead of having a long single inclination in the ramp, two short double inclinations can be made. By this we can prevent the sudden loss of energy. This in-turn increases the flame stabilization during Combustion.