亚燃冲压发动机中凹腔与V槽火焰稳定器性能对比分析

Comparison of characteristics of ramjet with cavity-based flameholder and V-gutter flameholder

通过亚燃冲压发动机直连式试验和数值计算,对凹腔火焰稳定器及V槽火焰稳定器的点火性能和燃烧性能进行了初步研究.结果表明,凹腔火焰稳定器可以直接用高能火花塞点燃,而V槽火焰稳定器只能用氢气引导火焰点燃;火焰稳定方式与燃料的喷注方式相对应,中心喷注方式适用于V槽火焰稳定器,壁面或者贴近壁面的喷注方式适用于凹腔火焰稳定器.燃烧性能方面,凹腔属于边区组织燃烧方式,V槽火焰稳定器属于中心组织燃烧方式,更有利于已燃气体和未燃气体的混合.凹腔与V槽的燃烧效率较为相近,但V槽火焰稳定器具有较高的总压损失.

Experimental research and numerical simulation were carried out in order to study the characteristics of cavity-based flameholder and V gutter flameholder in liquid hydrocarbon fuel ramjet. The results suggest that flameholder based on cavity could be ignited by high energy spark igniter or hydrogen pilot flame, but flameholder based on V-gutter could only be ignited by hydrogen pilot flame. Also, the fuel injection mode was closely related to the flame holding mode. Central injection was applied to V-gutter and wall or nearwall injection applied to cavity. The combustion of ramjet with cavity was organized in the near-wall area but that of V-gutter organized in the central area, making it helpful to the mixing of the unburned and the burned. The combustion efficiencies of cavity and V gutter were very close to each other, but the pressure loss of V-gutter was a little higher.