鸟撞损伤风扇气动性能的适航符合性研究

Airworthiness Compliance Research of Aerodynamic Performance on Bird Strike Damaged Fan Blades

为探索鸟撞损伤对风扇叶片气动性能的影响及适航相关条款的符合性,选取某典型大涵道比风扇转子为研究对象,对鸟撞损伤模型进行简化,采用全周数值模拟方法,研究了中鸟对典型风扇转子叶片损伤后造成的风扇气动性能变化,结果表明:不同数量叶片损伤时,风扇近堵点流量、峰值效率、稳定裕度及峰值效率点推力都较原型有不同程度的下降,变化量与损伤叶片数不呈线性关系;损伤3片叶片时,风扇峰值效率点推力相较于原型下降11.35%,最大推力相较于原型下降20.68%,故满足适航审定中推力损失不超过25%的要求.不同数量的损伤叶片自损伤处到叶尖通道内存在不同程度的流动分离,并导致风扇进出口流场发生了不同程度的畸变.

In order to explore the impact of bird strike damage on the aerodynamic performance of the fan blade and the compliance of the relevant provisions in airworthiness certification, a typical high bypass ratio fan rotor was selected, then a bird strike damage model was simplified and the effect of middle-bird typ ical damage to the aerodynamic performance of the fan blade by full-annulus numerical simulation was re- searched. The results show： the mass flow at chock point, the peak efficiency, the stability margin, the thrust of peak efficiency point and the maximum thrust of different number of damaged blades decline inor dinately compared to the undamaged blade while the magnitude increases due to the increasing number of damaged blades. Wherein, when the number of damaged blade reaches three, the thrust at peak efficiency point decreases by about 11.35% and the maximum thrust decreases by about 20.68% compared to the undamaged blade, which meets the requirement in Airworthiness Certification that thrust losses of middle bird strike damaged fan can＇t exceed 25%. Different amount of the damaged fan blade has flow separation from the damage position to the blade tip within different degrees, and leads that the outlet flow field of the fan has different degrees of distortion.