detonation wave

...The flame front initially propagates at a speed much slower than the speed of sound, sending out a shock wave forward, but the gas undergoes adiabatic compression in the front, causing the pressure to rise suddenly and the flow rate to decrease, so shock waves from the rear catch up one after another, further increasing the pressure, causing the gas temperature to rise and spontaneously ignite. From that point on, the flame, accompanied by heat from the reaction, becomes a detonation wave, propagating at supersonic speeds (usually 1500 m/s or more). In this way, the detonation speed is initially small (deflagration), but gradually increases, exceeds the speed of sound, and eventually becomes constant (detonation), which is a transition that generally occurs in explosion phenomena. ...

*Some of the terminology that refers to "detonation wave" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…火炎面は初め音速よりはるかに小さな速度で伝播しながら前方へ衝撃波を送り出すが，気体は前方で断熱圧縮を受ける結果，圧力が急激に高まり流速が小さくなるため後方からの衝撃波がつぎつぎと追いついてきてさらに圧力が強められ，ガスの温度が高まって自然発火する。それから先は反応による発熱を伴った火炎が超音速(通常1500m/s以上)で伝播する爆ごう波detonation waveとなる。このように爆速は初め小さい(爆燃)が，しだいに上昇して音速を超えやがて一定となる(爆ごう)，という転移を伴うのが爆発現象において一般的である。…

※「detonation wave」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報