Investigations On The Influence Of Injection Scheme On The Supersonic Combustion Performance Of Hydrocarbon Fuel

The influence of wall transverse injection, strut and pylon to the supersonic combustion performance of hydrocarbon fuel was studied in this paper. The study has conducted more than one hundred Ma4 supersonic combustion tests and combined with numerical simulations method, using the engine thrust gain and the chamber nondimensional wall pressure as the main evaluation index.When the injection strategy was the wall transverse injection, the ignition and combustion characteristics of normal temperature kerosene, heated kerosene, mixing gas and ethylene were studied respectively. The results show that: the total temperature of incoming flow has a significant influence on the supersonic ignition and combustion performance of normal temperature kerosene, whereas the impact on heated kerosene is small; however cracking temperature, injection position, the combustion chamber configuration, and the equivalence ratio have greater impact on the supersonic ignition and combustion performance of heated kerosene; increased injection pressure for centralized injection can effectively improve the supersonic combustion performance of ethylene and mixing gas; the influence of injection location on ethylene performance of supersonic combustion varied with equivalence ratio, when equivalent ratio is relatively large, injection close to the downstream is better, when equivalent ratio is relatively small, injection close to the upstream is better; as the equivalence ratio increased, the supersonic combustion performance of normal temperature kerosene, heated kerosene, mixing gas and ethylene were improved; compared with heated kerosene and mixing gas, the supersonic combustion performance of ethylene is the best, and the mixing gas followed by heated kerosene.The influence of strut on the supersonic combustion performance of normal temperature kerosene and ethylene was studied. The results show that: Compared to pure wall transverse injection, strut can effectively improve the supersonic combustion performance of normal temperature kerosene, increase engine thrust gain but little effect on the ethylene.The influence of pylon on the supersonic combustion performance of normal temperature kerosene and ethylene was studied. The results show that: Compared to pure wall transverse injection, pylon can effectively improve the supersonic combustion performance of normal temperature kerosene, increase engine thrust gain a certain role in promoting the supersonic combustion performance of ethylene, but not very significant.