Performance Characterization of Single Expansion Ramp Nozzle at Hypersonic Mach Number

Abstract

Single Expansion Ramp Nozzle (SERN) is a direct extension nozzle where the gas pressure flows from one place to other works only on one side. The SERN is a hypersonic speed demonstrator vehicle due to its advantages and operational limitations. The demonstrator vehicle is designed to attain a cruise flight at a speed of Mach 6.2. The operating limits given as constraints are the atmosphere limitations, i.e., within the lower atmosphere wherein the vehicle has to run on air-breathing scramjet engines. The project emphasizes the effect of performance parameters, namely thrust, lift and moment, due to variation in jet Mach number and jet pressure through a nozzle. The nozzle is considered separately due to the experimental limitations. The CAD model designed for the nozzle is taken. Only the vehicle's nozzle section is dissected from the whole model for the numerical simulation. The GAMBIT software is used to mesh the model and tocreate the domain space. The model is a 3D structure aligned to the 3 axis coordinate system, where the body's length is aligned along the x axis and width of the body along the z-axis. The cowl is attached to the combustion chamber exit, providing pitching stability to the vehicle. The model analysis is done in FLUENT, where the model to be solved is exported from gambit and imported to FLUENT. The cowl arrangement affects the nozzle performance and the effect of performance due to change in cowl geometry is studied. This paper presents the study of the performance parameter’s interactions with jet pressure, Mach number and cowl deflection of the nozzle