一种进气道自起动特性检测方法

A test method for inlet self-starting ability detection

发展了一种应用于激波风洞中快速检测高超声速进气道自起动能力的实验方法。该方法通过在隔离段内预先设置轻质堵块,迫使进气道在风洞运行初期不起动,待堵块被吹出后,流道恢复畅通,进而考察进气道是否具有起动能力。实验采用高速纹影拍摄同步壁面压强测量的手段,对二元高超声速进气道的起动特性进行了研究。通过对纹影照片以及相应的壁面压强信号的分析,对所发展的自起动检测方法的可靠性进行了考核,并进一步研究了内收缩比对进气道起动特性的影响。在激波风洞中获得了进气道自起动过程以及起动/不起动双解区的流场特征和相应的壁面压强变化历程。

A new test method was developed to examine the self-starting ability of hypersonic inlets in a shock tunnel. It adopted a light obstacle as a flow plug, which could be rapidly blown out of the duct, to choke the inlet flow for unstarting at the initial stage of the shock tunnel oper- ation. Simultaneous high speed schlieren imaging and surface pressure measurements were ap- plied to determine whether the inlet would be restarted after the obstacle action. The initiations of unstart and restart processes were observed. A generic hypersonic inlet which exhibited self- starting characteristic was achieved in the shock tunnel. With the help of the newly developed test method, the flow characteristics in the starting/unstarting dual-solution area were also ob- served in an inlet with a large internal concentration ratio. The results indicate that various flow characteristics in the inlet can be performed in shock tunnels.