火焰稳定器相对参数对水冲压发动机燃烧及其内流场的影响

Effect of flame stabilizer relative parameters on combustion and flow field in water ramjet

在水冲压发动机燃烧室中设置钝体火焰稳定器,可使部分已燃高温燃烧产物在火焰稳定器后部的回流区内不断点燃新鲜的可燃混合物,从而实现稳定高效燃烧。通过改变火焰稳定器相对金属燃料入口高度及相对一次进水位置,对比分析了相对入口高度和相对一次进水位置两种不同相对参数对于燃烧室内掺混、燃烧以及火焰稳定效果的影响。结果表明:当相对高度H>1时,燃烧火焰无法稳定在回流区。当火焰稳定器相对位置不变时,在一定范围内,随着相对高度H减小,火焰稳定效果增加,且存在较优的相对高度(H=1)使燃烧室内的掺混效率和火焰稳定效果较好。当保持相对高度H=1不变的情况下,综合考虑火焰稳定效果、铝/水掺混效率以及发动机工作性能,L=0.5是较为理想的火焰稳定器相对位置。

When the blunt body flame stabilizer installed in the combustion chamber,part of the burnt high-temperature combustion products can ignite fresh combustible mixture in the recirculation zone at the rear of the flame stabilizer so that the stable and efficient combustion can be achieved.By changing the flame stabilizer relative metal fuel inlet height and relative primary water inlet position,the effects of two different relative parameters:relative metal fuel inlet height and relative primary water inlet position,on mixing,combustion and flame stability in the combustion chamber were compared and analyzed.The results showed that when the relative metal fuel inlet height H was greater than 1,the combustion flame cannot be stabilized in the recirculation zone.When the relative position of flame stabilizer was fixed,the flame stabilization effect increased with the decrease of relative metal fuel inlet height in a certain range.Furthermore,there was superior relative metal fuel inlet height(H=1),which made the mixing efficiency and flame stability better in the combustion chamber.When the relative metal fuel inlet height H=1 was kept unchanged,considering the flame stability,aluminum/water mixing efficiency and engine performance synthetically,L=0.5 was the ideal relative position of flame stabilizer.