Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
SCRAMJET DESIGN FOR ATMOSPHERIC FLIGHT FROM 23 KM TO 30 KM
Submission Author:
Guilherme Melo Chaves , MG
Co-Authors:
Guilherme Melo Chaves, Marcelo Serrano Zanetti, João Felipe De Araujo Martos, George Marinho, Pedro Paulo Batista de Araújo, Paulo Toro
Presenter: Guilherme Melo Chaves
doi://10.26678/ABCM.COBEM2021.COB2021-0322
Abstract
In 2020, Aerospace Engineering undergraduate students, from Universidade Federal de Santa Maria (Santa Maria/RS), started to develop research in hypersonic airbreathing propulsion. In this present work, theoretical-analytical methodology based on oblique shock wave, one-dimensional (Rayleigh) flow with heat addition and expansion wave (Prandtl-Meyer) coupled area ratio equations, considering calorically perfect gas (no real gas effects) and no viscous effects (no boundary layer) assumptions, are applied to preliminary scramjet design. A two-dimensional hydrogen powered generic scramjet, with mixed (external and internal) compression inlet, for a flight starting at the speed of 1723 m/s (corresponding to Mach number 5.8) at 23 km and ending at the speed of 2051 m/s (corresponding to Mach number 6.8) at 30 km, considering shock on-lip and shock on-corner conditions. The zeroth and the first laws of thermodynamics are used to estimate the airflow static temperature, T3, while the energy conservation law is used to estimate the Mach number, M3, at the combustion chamber entrance. The turning (deflection) angles of the compression section ramps are optimized by applying the constant total pressure (recovery) ratio across each incident oblique shockwave (Oswatitsch criterion adapted for hypersonic scramjet inlet). The scramjet engine operates as an (opened) Brayton thermodynamic cycle, then, the static pressure, at the scramjet trailing-edge, is the static pressure at a given flight altitude, and it provides the turning (deflection) angle of the expansion section ramp (trailing-edge). Airflow thermodynamic properties from leading-to-trailing edges as well as the uninstalled trust are presented for both cases.
Keywords
Scramjet, supersonic combustion, hypersonic airbreathing propulsion
