To understand the effects of underwater explosion phenomena, as in the case of shock forming, it is
necessary to accurately measure bubble pulses, as well as underwater shock waves. In the measurements
of underwater explosion phenomena by a tourmaline sensor, a shift of baseline to negative
pressure in the bubble pulse after the passage of shock wave is observed. The shift of the baseline
makes the precise quantitative measurements of bubble pulses difficult. It is demonstrated that the
pressure sensor using fluoropolymer can maintain the baseline of bubble pulse at the zero value after
the passage of the shcck wave.
Precise measurements of peak pressure and impulse of the bubble pulse, as well as the underwater
shock waves, were performed by the pressure sensor using fluoropolymer. The experimental results
show that the peak pressure of bubble pulse is about 10 - 30 % of the peak pressure of shock wave, but
the impulse of bubble pulse is about 1.5 - 2.5 times bigger than that of shock wave, in the measured
scaled distance range. This is due to the fact that the duration of the bubble pulse is about ten times
longer than that of the shock wave.
フッ素系高分子を使用した圧力センサーを用いて, エマルション爆薬の水中爆発により生じたバブルパルスの測定を実施し, バブルパルスの最大圧力と力積の解析方法の検討を行うと共に, 距離減衰式の導出を行った｡
実験の結果, エマルション爆薬の水中爆発により生じたバブルパルスの最大圧力は衝撃波の最大圧力の数分の1程度であるが, バブルパルスの力積の方が衝撃波の力積よりも大きいことが判明した｡
これは, バブルパルスの持続時間が数ミリ秒程度と, 水中衝撃波の持続時間に比べ1桁程度長く, 圧力が長時間維持される為であった｡