基于acetone-PLIF技术的超燃冲压发动机燃烧室燃料/空气掺混特性

针对超燃冲压发动机燃烧室内燃料/空气掺混特性，设计了一套以acetone-PLIF（planar laser-in-duced fluorescence）为技术手段的流动显示测量系统，得到了4种不同结构交错楔形支板在不同特征截面处的丙酮荧光图像，研究了喷嘴位置和尾缘角这两个变量对燃料/空气掺混效果的影响。结果表明:“基准”支板NL1的流场结构主体上表现为横向“S”形曲线，燃料/空气的掺混效果相对普通； NL2支板虽然增大了一些丙酮的扩散范围，但有荧光信号的掺混区域面积却反而有所下降；而引入扩张型尾缘角变量的EL1支板则是大幅改善了燃料/空气的掺混效果，54 mm截面的丙酮分子充满了较大片区域，掺混区域超过截面的1/2。 

Fuel/air mixing characteristics of scramjet combustor based on acetone-PLIF technology

In order to study fuel/air mixing characteristics in scramjet combustor,a non-invasive flow visualization system was designed based on acetone-PLIF(planar laser-induced fluorescence) technology. The acetone fluorescence images of four kinds of shaped struts were obtained at different sections, and the effects of nozzle position and trailing edge angle on fuel/air mixing were studied. The results showed that the flow field of the "standard" NL1 strut was of a transverse "S" curve,which had normal mixing effect in the four struts. The NL2 strut increased a few acetone diffusion range, but decreased mixing area with fluorescence signals. The EL1 strut with an expanded trailing edge angle can greatly improve effect, since the acetone molecules filled over a half of the cross section at 54 mm downstream the strut.