考虑动力影响的大型运输机增升构型气动特性研究

The research of aerodynamic characteristics of high-lift configuration of large transport plane with the effect of engine jet

为满足现代大型运输机增升系统高效、稳定的设计需求,以某型运输机增升构型为研究对象,通过数值模拟方法研究了动力因素对全机气动特性的影响。数值模拟结果表明:在动力因素影响下,全机最大升力系数增加46.2%,失速迎角增加11°;全机静安定度降低30.89%。通过流场机理分析可知:动力因素不仅对短舱后方襟翼当地流场有较大改善,而且对短舱和主翼上表面流场以及平尾当地迎角也有显著影响。基于以上结论,在运输机增升构型设计过程中,要充分考虑动力因素对各个部件当地流场的影响以提高升力特性;同时要权衡动力因素使机翼低头力矩增加、平尾低头力矩降低这两种趋势相反的影响结果以改善俯仰力矩特性。

To satisfy the design request of efficiency and stability of high-lift system of large transport plane,by the method of CFD （Computational Fluid Dynamic）,the research of aerodynamic characteristics of high-lift configuration of large transport plane with the effect of engine jet has been done.The result of nu-merical simulation demonstrates that with the effect of engine jet,the maximum lift coefficient increases by 46.2%,and the stall angle increases by 11 degrees,longitudinal stability factor decreases by 30.89%.Con-clusion can be obtained by analyzing the physics characteristics of flow that the engine jet not only changes local flow fluid of flap after the engine but also changes the local flow fluid on the upper surface of nacelle and main wing and the local angle of attack of horizontal tail.Given the conclusion obtained above,during the procession of designing high-lift configuration of STOL transport airplane,for the lift characteristics the effect of engine jet on the local flow fluid of each part has to be considered;for the pitch moment characteris-tics the reverse effect of engine jet increasing nose-down pitching moment of wing and decreasing that of hori-zontal tail must to be weighted.