关键词: 固体火箭;引射式发动机;引射效率;推力增益;数值模拟

Abstract: In order to reduce the production cost of the target drone and increase the thrust-to-weight ratio of the target drone engine, a solid rocket ejector-based combined engine model is put forward. It consists of a solid rocket and a reburning chamber. The layout can be divided into solid rocket built-in and solid rocket external. For getting the optimized layout structure of engine, the numerical simulation of flow in the built-in and external layout engines are carried out by quantitative heating in the reburning chamber simulating the engine working process. The calculation results show that for both the internal and external engine, the ejection efficiency is reduced with the increase of heating quantity under the same inlet ejecting area. The built-in layout engine thrust is basically unchanged, and the external layout engine thrust gradually increased. It has high thrust and thrust gain (maximum up to 39.3%). Thus, it can be seen that the external engine has better thrust performance. In order to further optimize the external layout engine, the performance of six cases of engines, i.e., the ratio of the ejection inlet size to the solid rocket outlet diameter (L/D) being set as 1/6, 2/6, 3/6, 4/6, 5/6, 6/6, are studied. The results show that as L/D increases from 1/6 to 6/6, the ejection efficiency, thrust and thrust gain increase first and then decrease. When L/D is equal to 4/6, the engine’s ejection efficiency and thrust are maximized and the engine’s performance is optimal.

Key words: Solid rocket;Ejecting engine;Ejection efficiency;Thrust gain;Numerical simulation