ENDGAME - Laboratory Experiment 2024-03-21 Exp. 002 - 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 a pipe with an inner diameter of 4 cm (outer diameter 5 cm) and 80 cm long. The volume of pressurized gas injected into the pipe was ~3000 cm3. In some cases a pressure sensor has been placed at the vent of the conduit to record pressure variations during the experiment. 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）技术的激波管实验。

本激波管实验装置由高压储气腔与圆柱形实验段组成，二者通过膜片脉冲阀连接，该阀可将高压气体快速释放至常压实验段内。高压储气腔内填充的压缩空气相对于环境压力具有设定过压，最高可达8 bar。实验段管内可为空（即填充环境条件下的空气），或装入设定质量的细小颗粒。本次实验采用的实验段管内径为4 cm，外径为5 cm，管长80 cm。注入实验段的高压气体体积约为3000 cm³。部分实验中，会在管道排气口处安装压力传感器，以记录实验过程中的压力变化。高速相机采集图像的帧率为30000 fps。

当脉冲阀开启时，会产生射流，同时激波与声波在大气中传播，通过高速纹影阴影摄影技术可观测到上述波动现象。