爆震管内缓燃到爆震转变距离和时间的数值模拟

摘要

为了研究爆震管内缓燃向爆震转变(该过程称为DDT)距离和时间,对爆震管内DDT过程进行了二维数值模拟,研究改变氧气浓度及使用辛烷和氢气双燃料对爆震管DDT距离和时间的影响.数值模拟结果表明:当氧化剂中氧气体积分数占20％ ～ 40％时,增加氧气体积分数可以缩短DDT距离和时间;当氧气体积分数大于40％时,初始火焰在极短的时间和距离发展为稳定传播的爆震波;相同条件下,使用辛烷和氢气双燃料较单一辛烷燃料能获得更短的DDT时间和DDT距离,双燃料中氢气体积分数20％时,影响效果最好.%In order to study deflagration to detonation transition (DDT) distance and time in detonation tube,numerical simulation of the DDT in detonation tube and the effects of changing the oxygen concentration were investigated.And the effects of using octane and hydrogen dual fuel on the DDT were investigated.The results of numerical simulation show that when the volume fraction of oxygen in the oxidant is 20％ ～40％,increasing the oxygen volume fraction can reduce the DDT distance and time.However,the initial deflagration develops to detonation immediately when the volume fraction of oxygen is greater than 40％.Compared to single octane,using octane and hydrogen dual fule results in shorter DDT time and DDT distance under the same conditions,and when the volume fraction of hydrogen in dual fuel is 20％,its effect is the best.