目前以碳氢燃料与空气可爆混合物的直管爆震室存在较长的爆燃向爆震转变(Deflagration to Detonation Transition,简称"DDT")距离,从而导致发动机整机长度过长等问题。为解决此问题,采用8种螺旋构型的爆震管替代现有国内外普遍研究的直管构型的爆震管进行了一系列实验。首先对不同螺旋结构的爆震管进行冷态流阻特性实验,得出了螺旋结构参数和流阻的关系;再结合冷态实验结果,选取4种螺旋结构进行了热态爆震实验。实验结果表明,所有螺旋结构均可获得充分发展的爆震波;螺旋爆震管缓燃向爆震转变时间随螺旋中轴线曲率半径增加而减小;相对于长2.0m的直管爆震管,螺旋爆震管DDT时间缩短了0.415~0.589ms,DDT距离沿螺旋线方向缩短了0.35m,爆震管轴向长度缩短了0.78~1.28m。
The deflagration to detonation transition(DDT) distance is long for current straight hydrocarbon-air pulse detonation chamber(PDC) which makes the engine not short enough for its engineering application.The experimental research presented in this paper focused on the solution of this problem.At first,the flow resistance experiments of 8 different spiral detonation tubes and one straight tube were performed,and the relationship between spiral geometry parameters and flow resistance was concluded.According to the conclusion,the detonation experiment was conducted using 4 spiral tubes in the resistance experiments.The detonation experiment results showed that all the selected tubes could obtain fully developed detonation waves,and the DDT time was reduced with the increasing of spiral chamber curvature.Compared with the straight tube,the DDT time and distance were decreased by 0.415~0.589ms and 0.35m respectively,and the chamber axis length was shorten by 0.78~1.28m in the spiral chambers.