关键词: 运载火箭;液氧煤油发动机;助推器;技术特征;推重比

Abstract: Long March 5 is China’s new generation of large-scale launch vehicle （code-named CZ-5）. The core stage is bundled with four boosters， and each booster uses a dual-unit parallel liquid oxygen kerosene high-pressure staged combustion engine. Considering the real situation of the first launch of the Long March 5， this paper analyzes the failure modes of launch vehicles at home and abroad， and puts forward the measures that should be taken to avoid the risk of the booster system. Combined with the starting characteristics of booster stage and the first-stage engines， the ignition matching characteristics of the different engines in the first launch of the Long March 5 are discussed. The development history， technical characteristics， and adaptability of thermal environment for YF-100 series liquid oxygen kerosene engine are briefly described， and the engine’s potential of reusability and wide-range thrust adjustment is analyzed with emphasis. The thrust-to-weight ratio of liquid oxygen kerosene staged engines is compared， the impact of engines with different thrust-to-weight ratios on the carrying capacity of rocket is studied， and the methods to improve engine’s performance are summarized （such as using pump back swing technology， high-strength and light-weight Materials， etc.）. It is pointed out that the new generation of liquid oxygen kerosene engine must pursue high performance， high thrust-to-weight ratio， lower cost and enhance adaptability under the premise of high reliability.

Key words: Launch vehicle;Liquid oxygen kerosene engine;Booster;Technical characteristics;Thrust-to-weight ratio