壁面孔型对超声速气流中喷注特性的影响

Effects of different wall surface orifices on injection characteristics of supersonic air flow

超声速气流中,燃料与来流空气的高效混合是燃烧室实现点火、稳焰及高效燃烧组织的前提。国内外研究者已对比研究了不同壁面孔型对超声速气流中喷注、混合特性的影响,相比于最常见的圆形喷孔,菱形、楔形-半圆、箭形及针形等喷孔用于超声速气流燃料喷注时,不仅有利于降低喷孔前缘边界层的分离,而且也有利于提升射流穿透深度;相比于单孔喷注,组合型喷孔能进一步增强燃料与来流空气在射流远场的混合效果。通过综述各型喷孔的喷注特性,分析提出了适用于超声速燃烧组织的壁面喷注孔型及其工程应用条件。

The efficient mixing of fuel jet and air flow in supersonic gas flow is a precondition to achieve ignition, flame stabilization and high efficiency combustion. The effects of different wall surface orifices on the injection and mixing characteristics have been studied by many researchers at home and abroad. Compared with the common circular orifice, diamond-shaped orifice, wedge-semicircle shaped orifice, arrowhead shaped orifice and stinger-shaped orifice are beneficial to reduction of the boundary layer separation at orifice front edge, and improvement of the penetration depth of the jet flow. Compared with the single orifice injection, the combined orifice can further enhance the mixing effect of the fuel and the incoming air in far field. In this paper, the wall surface injection orifice and engineering application condition that apply to the supersonic combustion are proposed on the basis of analysis of the injection characteristics of various orifices.