ENDGAME - Laboratory Experiment 2024-01-18 Exp. 011 - High Speed Camera data

Shock-tube experiments in combination with high speed Schlieren shadow photography. The shocktube setup consists of a high-pressure reservoir connected with a cylindrical tube through a diaphragm pulse valve which allows a fast release of pressurized gas into the ambient pressure tube. The high-pressure reservoir is filled with compressed air at a given overpressure with respect to ambient pressure (up to 8 bar). The pipe was either empty (i.e. with air at ambient conditions) or filled with a given amount of small particles. We adopted pipes an inner diameter of 4 cm and different lengths (20, 30 and 80 cm). We also considered different volumes of pressurized gas (~650 cm3 and ~1550 cm3). A pressure sensor has been placed at the vent of the conduit to record pressure variations during experiments. Images from the high speed camera were collected at a frame rate of 30000 fps. When the valve is open, a jet flow is produced, with shock and acoustic waves propagating in the atmosphere, which become visible due to the high speed Schlieren shadow photography.结合高速纹影阴影摄影（Schlieren shadow photography）的激波管实验。 本激波管实验装置由高压储气罐与圆柱形实验段通过膜片脉冲阀连接而成，该阀可将高压气体快速释放至常压实验管内。高压储气罐内充装的压缩空气相对于环境压力存在设定过压，最大过压可达8 bar。实验管可处于空置状态（即内部为环境条件下的空气），或装填设定质量的细小颗粒。本实验采用的实验管内径为4 cm，长度涵盖20、30与80 cm三种规格；同时设置了不同容积的高压储气罐，对应充装的高压气体体积约为650 cm³与1550 cm³。实验导管的排气口处安装有压力传感器，用于记录实验过程中的压力变化。高速相机以30000帧每秒（fps）的帧率采集实验图像。 当膜片脉冲阀开启时，将产生射流，伴随激波及声波在大气中传播，而这些现象可通过高速纹影阴影摄影清晰呈现。