Abstract: Hybrid rocket motor (HRM) capable of linking up the specific impulse gap between solid rocket motor (SRM) and liquid rocket motor (LRM) is under extensive research. Some active thermal protection nozzles applied successfully in the SRMs and LRMs could not fulfill the long service requirement (≥200s) of the HRMs due to the strong oxidation and ablation environment. This work employs the typical scheme design of HRM, by using the active thermal protection nozzle for the accomplishment of the thermal structural design, structural material preparation and material selection of HRM nozzle working up to 200s. There are two cycles of firing test described. Both the initial and improved nozzle have successfully passed the firing test lasting 200s. The test results have shown that: （1) The thermal structural design and the preparation of anti-oxidation material resistant to strong oxidation and ablation at higher temperatures are the two key factors to a longer work time of the nozzle of hybrid rocket motor. （2) The use of dual phases ceramic matrix composites could be beneficial to the performance consistency, reliability of hybrid rocket nozzle and relatively lower ablation rate of material. （3) The improved nozzle greatly improved the performance of HRM, which could help the increase of the chamber pressure by 159% while the increase of motor thrust by 43%.

摘要： 能衔接固体发动机和液体发动机比冲的固液发动机得到广泛研究。由于固液发动机的强氧化剥蚀环境，发动机的主动热防护喷管很难满足长时间工作的需求。利用固液火箭发动机，喷管采用主动热防护方案，完成了工作时间长达200s固液发动机的喷管热结构型式设计、热结构材料制备和热结构材料筛选试验。完成两轮热试验工作。初始状态喷管和改进状态喷管均成功通过长达200s固液发动机热试车考核。研究结果表明：（1）固液发动机喷管的热结构设计与抗强氧化、高温烧蚀和剥蚀的材料制备，是保证喷管长时间稳定可靠工作的两个技术关键。（2）采用复相陶瓷复合材料结构件改进喷管的性能一致性、工作可靠性更高，材料烧蚀率相对更低。（3）改进喷管大幅度地提高固液发动机性能，提升燃烧室内压159%，提高发动机推力43%。

关键词: 固液发动机;喷管;主动热防护;长时间;抗强氧化