Abstract: A series of tests about simple cycle detonation at a tube were performed to study the deflagration to detonation the transition characteristics. The reactants used were stoichiometric acetylene and oxygen mixture, with some inert gas nitrogen. The parameters changed in the test included initial mixture pressures varying from 0 02 MPa to 0 1 MPa, the diluent concentrations varying from 0% to 70%, and three kinds of obstacles. The flame velocities were measured in the tests to obtain the DDT distances. Finally, it was found that DDT distances were increased with initial pressure down, or diluent concentration up, and lowered with inclusion of obstacles, especially in mixture with low pressure or high amounts of diluent.

Key words: Detonation;Deflagration to detonation transition;Pulse detonation engine;Flame propagation

摘要： 为了获得预混气爆震管中爆燃到爆震转捩 (DDT)距离的变化规律 ,进行了一系列的单循环爆震试验 ,其中预混气为按化学恰当比配制的乙炔与氧气以及稀释剂氮气 ,变化的试验参数包括 :预混气初始压力 (0 0 2MPa～ 0 1MPa)、稀释剂的浓度 (0 %～ 70 % )及三种扰流片的形状。试验测得了不同工况下爆震管内火焰传播速度 ,并由此确定了DDT距离及其变化规律。试验结果表明 ,预混气初始压力下降或稀释剂浓度增加时 ,DDT距离增大 ,而安装扰流器后DDT距离明显缩短

关键词: 爆轰;爆燃到爆震转捩;脉冲爆震发动机;火焰传播