Abstract: In order to study the chamber pressure upper limit of the low-thrust liquid rocket engine, the engine configuration design and cooling performance calculation were performed and validated for a 1kN N₂O₄/MMH liquid rocket engine utilizing liquid film inner cooling and radiative outer cooling. With the flux of film coolant fixed, the variations of wall temperature of the gas-side and heat flux were compared carefully. It is found that the dimension of the thruster chamber, as well as the film length, is decreased significantly and the wall temperature is then increased under the design conditions of the same specific pulse and the same film coolant flux. There is an upper design limit of chamber pressure under the normal work condition of the wall material. 

Key words: Liquid rocket engine; Thrust chamber; Film cooling; Radiative cooling

摘要： 为了研究液膜内冷和辐射外冷方式小推力火箭发动机室压的设计上限,针对推力为1kN四氧化二氮/一甲基肼火箭发动机,开展了不同室压下发动机推力室构型设计和冷却性能计算。固定液膜冷却剂流量,比较分析了不同推力室室压下气壁温和热流的变化规律。研究发现,在推力和膜冷却流量不变条件下,随着室压的提高,推力室尺寸大幅度减小,热负荷大幅增加,最高气壁温也增加；在选用材料正常工作条件下,存在室压设计上限。 

关键词: 液体火箭发动机;推力室;膜冷却;辐射冷却 