ENDGAME - Laboratory Experiment 2024-01-18 Exp. 020 - 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（shock-tube）实验与高速纹影阴影摄影（Schlieren shadow photography）技术联用开展。
该激波管实验装置由高压储气腔与圆柱形实验管通过膜片脉冲阀连接构成，该阀可实现高压气体快速释放至常压实验管内。高压储气腔充装的压缩空气相对于环境压力具有设定过压，最大过压可达8巴（bar）。实验管可保持空置（即填充环境条件下的空气），或充装定量的细小颗粒。实验管内径统一为4厘米，长度设置为20、30与80厘米三种规格；同时实验采用了两种不同容积的高压储气腔，容积分别约为650立方厘米与1550立方厘米。实验管路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。高速相机的采集帧率设定为30000帧每秒（fps）。
当膜片脉冲阀开启时，会产生射流，伴随激波及声波在大气中传播，上述现象可通过高速纹影阴影摄影技术清晰观测到。