Numerical Study on the Effect of Jet on the Operation of Powder Fuel Scramjet

Abstract

Metal powder fuel has high energy and volume calorific values, and it is an excellent power fuel for hypersonic aircraft in the future. However, metal powder has poor flow characteristics and is difficult to be effectively mixed with air when supersonic air is injected. The mixing degree of fuel and air is an important factor to the efficiency of the engine. One way to solve this problem is to introduce a jet (the primary jet) upstream of the powder fuel inlet to improve the mixing degree of fuel and increase the residence time. In this study, a doublehole jet two-dimensional scramjet combustor structure was established, the effects of different initial jet conditions on the performance of scramjets was studied and analyzed. The results show that the introduction of the primary jet can effectively improve the mixing degree of the powdered fuel and air in the combustion chamber, prolong the residence time of the particles in the combustion chamber and improves the combustion efficiency of the metal powder. However, both the combustion efficiency of the metal powder fuel and engine thrust increase and then decrease when the mass flow rate of the primary jet increases.