除冰气囊以及简化模型对气动特性影响研究

Research on the influence of deicing airbag and simplified model on aerodynamic characteristics

除冰气囊作为涡桨类飞机常用的除冰系统,评估其对全机气动特性的影响对飞行性能与安全有重要意义。基于某飞机上安装的气囊除冰系统,采用CFD方法模拟其工作时的全机气动特性,研究气囊简化模型对计算结果的影响。结果表明:随气囊膨胀高度增加,对全机气动特性影响显著,失速迎角提前约10°,最大升力系数损失近60%,最大升阻比降低约2.9;受膨胀气囊外形影响,机翼前缘呈展向流动特征,后缘流动分离区域长度与除冰气囊的安装长度相当;机翼前缘压力分布受膨胀气囊外形的影响出现震荡,从而影响整个翼面的压力分布;随简化气囊膨胀高度增加,失速迎角最大提前约1°,最大升力系数损失约21%,最大升阻比降低约2.2。

As a common deicing system for turboprop aircraft,it is of great significance to evaluate the influence of deicing airbag on the aerodynamic characteristics of the aircraft.Based on the aerodynamic deicing system installed on one aircraft,simulating the aerodynamic characteristics when the deicing airbag working by using the CFD method,and analyzing the influence of the simplified deicing airbag model on the calculation results.The results suggest that:with the height of the deicing airbag increases,the effect on the aerodynamic characteristics of the aircraft becomes more obviously,the stall angle of attack is about 10°in advance,the maximum lift coefficient lost nearly 60%,and the maximum lift-to-drag ratio decreased by about 2.9.Influenced by the expansion of the deicing airbag,a flow along the wingspan appears in the leading edge,and the length of separation zone in the trailing edge is the same as the deicing airbag.The pressure distribution at leading edge is oscillating because of the expanded deicing airbag,so the whole airfoil’s pressure distribution is further affected.Besides,with the height of the simplified deicing airbag increases,the stalling angle is about 1°in advance,the maximum lift coefficient lost nearly 21%,and the maximum lift-to-drag ratio decreased by about 2.2.