ϕ3.2mm BKNO₃ペレットの低圧下における燃焼速度の取得

抄録

The burning rates of small sized Boron Potassium Nitrate (BKNO₃) pellets (3.2-mm-dia., B:KNO₃: binder = 28:70:2) under low pressures were experimentally measured; they increased with pressure (r = 71.1p^0.589[mm], p[MPa]) at an ambient pressure higher than 5 kPa and exhibited little dependence on pressure (r = 3.0±0.5mm/s) at an ambient pressure lower than 5 kPa. The measured pressure increase after reaction becomes smaller under 1 kPa and the photographs taken by a high-speed camera showed unreacted particle emissions at 0.2kPa. These results suggest that the reaction of BKNO₃ at low pressures takes place in condensed phase. From thrust stand measurement, the pressure working on the combustion surface is estimated to be 1.2kPa, which implies that the dependence of burning rates on ambient pressure vanishes under around 1kPa.