Water Components Of Scramjet Combustor Performance

It is very important to develop the hypersonic vehicle in aeronautic and astronautic in 21^st century. The hypersonic vehicle technology is the most important progress following with stealth technology in military domain. The scramjet, which is the propulsion of hypersonic vehicle, has become the focus in many military developed countries.The ground test is very important for the research of scramjet. It is necessary to simulate the high enthalpy, high pressure, Mach number and the same concentration of oxygen species as air in hypersonic flight. Most extensive facilities for evaluating hypersonic airbreathing propulsion concepts rely on combustion air pre-heaters to provide flight enthalpy simulation. As a byproduct of this method of air heating the resulting free stream is significantly contaminated by some species not normally present in atmosphere air. The experiment results for the vitiated test medium are different from those for clean air. It's necessary to investigate the effect of test medium contamination on the performance of scramjet combustor.In this thesis, the mole fraction of H₂O at the exit of hydrogen fueledheater is computed by the code. The finite-rate chemical kinetics model and the K-ε turbulence model are used to simulate the flow field and performance of combustor of the clean air and the vitiated test medium. The results indicate thatthe H₂O species of contamination test medium promotes ignition and flame-holding, but decreases the combustion efficiency in scramjet combustor.