JF-16膨胀管流场分析及升级改造

Flow field analysis of JF-16 expansion tube and its upgrade

膨胀管(风洞)是少数几种具备超高速流动模拟能力的地面试验设备之一,针对中国科学院力学研究所高温气体动力学国家重点实验室的爆轰驱动膨胀管JF-16,通过高焓流动数值模拟方法辅助诊断JF-16的流场特性可以发现,高温真实气体效应可以显著增加激波对气体的压缩能力并影响强激波结构,加速段内试验气流静温及化学成分较真实飞行条件有所偏离。为此对JF-16进行升级改造,通过在加速段末端加装锥形喷管,利用喷管的定常膨胀过程进一步调整试验气流的静温,进而提高试验气流品质,同时可以扩大试验区尺度。数值模拟结果表明8°锥角为最优选择,此时试验区尺度可扩大至140mm。

An expansion tube/tunnel is a ground-based test facility to generate hypervelocity test flow for the study of reentry physics. A detonation-driven expansion tube （JF-16） has been built at State Key Laboratory of High-temperature Gas Dynamics to generate relatively steady and clean test flow with high enthalpy. Numerical simulation is presented as an indirect approach to diagnose the key flow field features of JF-16. It indicates that real gas effect can enhance the compression capability of the shock wave and influence its structure. What is more, the temperature and chemical composition of the test flow in acceleration tube differ from the real flight condition. As a result, to upgrade the JF-16 facility, a conical nozzle has been designed at the end of acceleration tube. The main purpose of the nozzle is to adjust the temperature of the test flow by utili-zing steady expansion process and improve its quality. Meanwhile the available test core size can be increased to accommo-date large-scale models. Numerical simulation results show that 8＊ is the optimum angle of nozzle and the test core size can be expanded to 140 mm.