喷注流强分布对高频纵向燃烧不稳定性抑制效果  

Suppression effect of injection intensity distribution on longitudinal combustion instability

作　　者：汪广旭 谭永华[2] 庄逢辰 陈建华 杨宝娥 洪流 WANG Guangxu;TAN Yonghua;ZHUANG Fengchen;CHEN Jianhua;YANG Bao’e;HONG Liu(Key Laboratory for Liquid Rocket Engine Technology,Xi’an Aerospace Propulsion Institute,Xi’an 710100,China;Academy of Aerospace Propulsion Technology,Xi’an 710100,China;Department of Aerospace Science and Technology,Space Engineering University,Beijing 101416,China)

机构地区：[1]西安航天动力研究所液体火箭发动机重点实验室,西安710100 [2]中国航天推进技术研究院,西安710100 [3]航天工程大学宇航科学与技术系,北京101416

出　　处：《航空学报》2022年第9期378-389,共12页Acta Aeronautica et Astronautica Sinica

基　　金：液体火箭发动机技术重点实验室基金(614270419)。

摘　　要：径向喷注流强分布被用在现役多个型号的常温自燃推进剂液体火箭发动机中,是除使用声学阻尼装置以外最重要的燃烧不稳定性工程抑制措施,因此需要对其抑制效果开展深入研究。采用独立喷注器思路,设计了采用撞击式喷注器的自燃推进剂模型燃烧室,在模型燃烧室内激发高频纵向燃烧不稳定现象的基础上,进一步开展了不同喷注流强分布方案下的高频纵向燃烧不稳定性实验,分析了对喷注流强分布的抑制效果。研究表明:对于液滴蒸发作为速率控制过程的情况,提高“驼峰区”流强分布能够改善模型燃烧室的高频纵向稳定性,但改善效果与燃烧特征长度的变化相对燃烧室长度的大小有关。相对于短燃烧室工况,长燃烧室工况下,由喷注流强分布引起的相对燃烧特征长度的变化幅度降低,相应流强分布的抑制效果降低;相对于低室压工况,高室压下推进剂液滴蒸发过程加快,推进剂掺混效率提高,通过高流强区较大初始液滴粒径控制燃烧分布的效果被弱化,相应流强分布的抑制效果降低。各喷注器在高室压、长燃烧室工况下均激发了较大幅值振荡,且振幅分布与是否提高“驼峰区”流强无关。Radial injection intensity distribution has been adopted in many liquid rocket engines using storable hypergolic propellants,and has been one of the most important suppression methods of combustion instability for these engines in engineering,except for acoustic damping devices.However,these engines are still confronted with some risk of combustion instability,which means that deep study on its suppression effect is still necessary.With the idea of independent injector,a model combustion chamber with impingement injectors of hypergolic propellant was designed,and experimental study on high frequency longitudinal combustion instability of different injection intensity distribution was conducted.It is found that for the case that droplet evaporation acts as the rate-control process,enhancing the injection intensity of the‘hump zone’can improve the high frequency longitudinal combustion stability,but the improvement effect depends on the relative result of the variation of combustion characteristic length and chamber length.Compared with the case of the short chamber,in the case with long combustion chamber,the relative result of the variation of combustion characteristic length due to the change of injection intensity distribution and combustion chamber length will be smaller,and the corresponding suppression effect will be weakened.Compared with the case of lower pressure chamber,in the case of high pressure chamber,evaporation of propellant droplets will accelerate and mixture efficiency will be improved,which means that the effect of controlling combustion distribution through much bigger droplets in high the intensity zone will be weakened,and suppression effect will be reduced accordingly.For the case with high chamber pressure and long chamber length,high amplitude pressure oscillation is excited for each injector,and distribution of amplitudes has no relation with the injection intensity in hump zone.

关 键 词：自燃推进剂 液体火箭发动机 喷注流强分布 燃烧不稳定性 抑制效果 

分 类 号：V434.4[航空宇航科学与技术—航空宇航推进理论与工程]