ENDGAME - Laboratory Experiment 2024-01-18 Exp. 009 - 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.本数据集基于激波管实验与高速纹影阴影摄影（Schlieren shadow photography）技术构建。 该激波管实验装置由高压储气室与圆柱形实验管段组成，二者通过膜片脉冲阀连接，可实现高压气体快速释放至常压实验管内。高压储气室充装的压缩空气相对于环境压力具备设定过压，最大过压可达8巴。实验管可选择空置（即填充环境条件下的空气）或装填定量细小颗粒；实验管内径统一为4厘米，配有20厘米、30厘米及80厘米三种不同长度规格，同时采用约650 cm³与约1550 cm³两种不同容积的高压气源。在管路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/秒的帧率采集图像。 当膜片脉冲阀开启后，会产生射流流动，激波及声波随之在大气中传播，借助高速纹影阴影摄影技术可清晰观测到上述流动现象。