Combustion stabilizations in a liquid kerosene fueled supersonic combustor equipped with an integrated pilot strut

Abstract

The numerical and experimental investigations have been conducted to test a newly designed integrated pilot strut. The integrated pilot strut consists of two neighboring small strut with shallow cavities, with the help of which, the fuel injection and flame holding are achieved in the supersonic combustor. The flowing characteristics in the internal flow duct of the pilot strut are evaluated with the numerical simulation method, results proving that a lower speed zone generates in the internal flow duct in the supersonic combustor and the local equivalence ratio in the low speed zone is suitable for combustion. Then, a series of experiments have been conducted in the flight condition of Ma=5, with stagnation state Tt=1270 K, Pt=1.20 MPa. Experimental results show that a pilot flame generates in the internal flow duct of the pilot strut, based on which, the main fuel injected from the sidewall of the strut is ignited, and the global flame is established in the whole combustor. The combustion of the main fuel leads to a thermal chocking at the exit of the strut. Further, the thermal chocking is beneficial to the self-stabilization of the pilot flame. With the combustion organization strategy of the pilot strut flame holding, the global flame is stabilized in a wide range of equivalence ratio changing from 0.15 to 0.75 in the supersonic combustor, and the combustion characteristics in different equivalence ratios are analyzed in this paper. The integrated combustion organization approach by the pilot strut with internal cavities is demonstrated feasible and a high combustion performance is obtained.