抄録
An experimental study was conducted using a 25-mm-bore ram accelerator at the Shock Wave Research Center, Institute of Fluid Science, Tohoku University. The ram acceleration was obtained with a methane-based mixture. Experiments were conducted repeatedly in order to extend ram acceleration regions. It was found that the motion of precursor shock wave and the diaphragm rupturing processes by a projectile were more important factor on the ram accelerator starting processes. The heated regions caused by the reflections of the precursor shock between the diaphragm and the sabot was observed by the pressure measurement. The diaphragm rupturing processes could be visualized through the high-speed framing photography and holographic interferometry.
