起飞迎角对尾吊发动机短舱进气效率的影响研究

Study on Air Inlet Efficiency of Tail Suspended Engine Nacelle Effected by Takeoff AOA

尾吊发动机短舱式布局的飞机,安装在后机身的发动机位于机翼上方,在起飞过程中,机翼的洗流作用会对短舱的进气效率产生影响。为了评估不同起飞迎角对发动机短舱进气效率的影响,本文在计算流体动力学软件Fluent中对飞机起飞构型的全机流场进行了数值模拟,着重考察了不同起飞迎角对短舱进气道总压恢复系数及进气畸变指数的影响情况。计算结果表明,对于尾吊式发动机短舱而言,起飞迎角增加将导致进气道总压恢复系数减小、进气畸变指数增大,从而使进气效率下降。

The aircraft with configuration of tail suspended engine nacelle normally has its engine installed in rear fuselage above wings, which may cause effect on air inlet efficiency due to wash flow on wings in process of takeoff.In order to assess the effects on air inlet efficiency of the engine nacelle at different takeoff AOAs, this paper depicts the numeric simulation on aircraft flow field under takeoff configuration by using Fluent software, the software to calculate the flow dynamics, it reviews with emphasis on the effects on total pressure recovery coefficient and air inlet distortion index of nacelle intake resulted from different takeoff AOAs. The calculation result shows the increase of takeoff AOA will cause reduction of intake total pressure recovery coefficient and increase of air inlet distortion index, which will further decrease the air inlet efficiency with consideration on tail-suspended engine nacelle.