涡破碎片控制尖脊进气道总压畸变的试验研究

Experimental investigation on caret inlet’s total pressure distortion controlled by vortex break fence

关键词:  进气道  流场畸变  涡破碎片+  地面试验

Key words:  Inlet  Flow distortion  Vortex break fence~+  Ground test

摘要:

地面静止状态下, 在Caret进气道进口下唇口外侧和外唇口下侧角落处存在一个较强的顺时针旋转大涡, 涡破碎片控制该进气道总压畸变, 即利用涡破碎片产生的反向旋转旋涡来抵消或减弱该旋涡。研究了涡破碎片分别安装在外唇口下侧和下唇口外侧时, 几何尺寸、安装位置、以及安装角对Caret进气道出口流场总压畸变影响趋势。研究表明, 安装在外唇口下侧的涡破碎片能改善总压畸变流场并可使Caret进气道在较小流量下使稳态总压畸变值减小 17%, 而安装在下唇口外侧的涡破碎片对畸变流场影响不大。

Abstract:

It is shown by experiment that there is a strong and large clockwise vortex at caret inlet’s entry corner between outer and bottom cowl lip under takeoff condition, which may cause heavy total pressure distortion at engine face, therefore, to reduce caret inlet’s distortion by vortex break fence （VBF） means counteracting or weakening the clockwise corner vortex by a counter-rotating vortex generated by VBF. Influences of different VBF size, fixed angle and position on inlet exit distortion were investigated by means of fixing VBF on outer and bottom cowl lip separately. The results show that the VBF fixed on outer cow-lip can improve inlet exit distribution of total pressure and cause nearly seventeen percent reduction of total pressure circumferential distortion indices (（Δσ）₀ and DC₆₀) under condition of exit Mach number 0.26, while there is little influence on inlet exit total pressure distortion when VBF is fixed on bottom cowl-lip.