Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Three-dimensional CFD investigation of the sidewall compression angle in a scramjet intake
Submission Author:
Guilherme Borges Ribeiro , SP , Brazil
Co-Authors:
João Vitor Siqueira, Guilherme Borges Ribeiro
Presenter: Guilherme Borges Ribeiro
doi://10.26678/ABCM.ENCIT2022.CIT22-0196
Abstract
During the 21st century, a great number of loads are assumed to be taken into orbit. The cost to put something into orbit is enormous and therefore the development of an air-breathing engine as an alternative for hypersonic propulsion is required. Scramjet (supersonic combustion ramjet) engines are often seen as a promising alternative to place payloads in the Earth's orbit. Such air-breathing engines have a simple structure and a few moving parts. Nevertheless, developing a scramjet intake is not a trivial task. High heat fluxes and pressure loads on the walls, shock-wave-boundary-layer interactions, and the risk of chocked flow inside the isolator channel are a few examples of obstacles that need to be addressed during the scramjet design. This way, this work has the purpose of investigating the effects of side wall compression inside the isolator. Computational Fluid Dynamics (CFD) simulations regarding the entire scramjet intake for the same flight conditions but varying the sidewall compression angle have been carried out. Mach number contour shows that the greater the compression angle the bigger the boundary layer separation near the upper wall. Regarding the total pressure contours, in general, the results seen in this work point out that the greater the side-wall compression angle the lower the overall total pressure, which is directly related to the boundary layer separation on the upper wall. Yet this work investigated the effects of varying the sidewall compression angle on the scramjet performance parameters. Results in this work suggest that the higher the compression angle the lower the pressure recovery factor and the isentropic efficiency, which means the scramjet intake becomes less effective. In accordance with this last conclusions, the analysis of entropy generation suggest the higher sidewall compression angle generates more entropy. By investigating these freestream parameters, as well as the contour results, this work can contribute to the early phase of scramjet engine design.
Keywords
Scramjet, Hypersonic Flow, CFD, Propulsion
