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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。
At present, there is a long distance between the detonation to detonation (Deflagration to Detonation Transition, “DDT” for short) in the straight-tube detonation chamber of the combustible mixture of hydrocarbon fuel and air. As a result, the length of the engine is too long . In order to solve this problem, a series of experiments were carried out by using eight types of helical detonation tubes instead of the straight tube detonation tubes commonly studied at home and abroad. Firstly, the cold flow resistance characteristics of the detonation tubes with different spiral structures were tested, and the relationship between the helical structure parameters and the flow resistance was obtained. Combined with the cold state experimental results, four kinds of helical structures were selected for the thermal detonation experiments. Experimental results show that all helical structures can obtain a fully developed detonation wave. The transition time from detonation to detonation of the spiral detonation tube decreases with the increase of the radius of curvature of the spiral axis. Compared with the straight detonation tube of 2.0 m in length, The DDT time of spiral detonation tube was shortened by 0.415-0.589 ms, the DDT distance was shortened by 0.35 m along the helix direction, and the axial length of detonation tube was shortened by 0.78-1.28 m.