多喷流干扰级间热环境风洞试验研究

运载火箭级间热分离过程中,级间段受高温高压喷流的影响,所处环境恶劣,研究级间热环境中压力、温度和热流分布规律对级间段结构的优化具有重要意义.在(φ)1m高超声速风洞中,采用以微型固体火箭燃气为喷流介质的热喷流模拟技术,模拟了运载火箭二级主发动机和四个游动发动机同时工作多喷流干扰条件下的级间热环境,并对级间压力、温度和热流测量试验技术进行了研究,获得了不同级间距、不同排燃窗开口数量情况下的二级底封头和一级前封头表面的热流、温度及压力分布特性.试验结果表明,级间距越小,分离环境越恶劣,压力、温度、热流分布越不均匀;总排燃面积保持不变,排燃窗开口数量变化,对一级前封头上的压力、温度、热流影响不大,但对二级底封头影响较为明显,随着开口数量的减少,二级底封头上压力、温度、热流值均有所增大.本项试验采用同轴热电偶测量了级间区域的热流,热流结果精准度的提高以及热流模拟准则还需进一步探索和研究.

Experimental investigation on interstage thermal environment with multi-jets interaction in wind tunnel

During the stage separation course of launch vehicle,the environment of stage is quite severe because of high temperature and high pressure.It is very important to investigate the pressure,temperature and heat flux distributions under the interstage thermal environment for the design of stage configuration.This paper presents the hot-jet simulation technique taking micro-solid rocket engine gas as the medium of jet,simulating thermal environment of multi-jets interaction with the second-stage main engine and 4 vernier engines running simultaneously in Φ1m hypersonic wind tunnel(HWT).Pressure,temperature and heat flux measurement techniques have also been developed.Pressure,temperature and heat flux characteristics of the first-stage fore-envelop head and the second-stage aft-envelop head,which vary with different separation distances and different numbers of exhaust windows,are introduced.The results indicate that environment of small stage separation distance is severe.The smaller separation distance is,the less uniform of pressure,temperature and heat flux distributions are.Different number of exhaust windows has little effect on the pressure,temperature and heat flux characteristics of the first-stage fore-envelop head while keeping the whole area of exhaust windows constant,and it’s in the different case for the second-stage fore-envelop head that these values would increase with the number of exhaust windows decreasing.The coaxial thermocouple is utilized to measure heat flux between stages,whereas some improvements on the accuracy of the heat flux measurement as well as the heat flux simulation rules need exploring and studying further.