Observation of shock wave elimination by a plasma in a Mach-2.5 flow

An experimental study on the influence of a plasma on the structure of an a ttached conical shock front appearing at the front end of a missile-shaped model has been carried out in a Mach-2.5 flow. The tip and the body of the model are designed as the cathode and anode for gaseous discharge, which pr oduces a spraylike plasma moving around the tip. It is observed that the pl asma has caused the shock front to separate from the model. The shock wave moves upstream in the form of a detached bow shock a sensible distance away from the model tip. The detached shock front appears to be highly disperse d in its new location as seen in the shadow video graphs of the flow. As th e discharge current increases, experimental evidence shown in the video fur ther reveals a distinct state of the flow without the presence of any shock wave. (C) 2000 American Institute of Physics. [S1070-664X(00)02705-1].