The Influence of the High-Pressure Part Length on Shock Waves Exiting from an Open Tube

The influence of the length of the high-pressure part on the flow field generated by an open shock tube is experimentally investigated, in particular with respect to the so-called critical length of the driver section. The differences seen when operating the shock tube with drivers below or above the critical length are presented. It is found that for an operation with short drivers (at or below critical length), the outflow following the shock and the vortex ring is unsteady, but the influence on the leading shock and the vortex is minimal.