飞机进气道锤击波载荷评估方法研究

Evaluation Approach of Hammer Shock Loading for Aircraft Inlet

进气道锤击波载荷是由航空发动机喘振超压引起的,其峰值压力可达到自由来流总压的2倍量级,为进气道结构设计的最大载荷。为了给新研飞机进气道设计提供最大载荷依据、降低结构质量,对增压比等影响发动机喘振超压的因素进行归纳总结,并进行了实测和评估分析,认为锤击波压比值的上限是由稳态压力畸变引起的喘振确定的,最大锤击波载荷基本上随发动机压比的增大呈线性增大;分析了锤击波载荷的特征和评估曲线,认为通过积累新研发动机地面试验数据和CFD手段可有效解决飞机设计的载荷输入,应用概率统计方法可有效降低复合材料结构的大"S"弯进气管道结构质量。

The hammer shock loading is the maximum loading in the inlet structure design caused by the engine surge over pressure,which peak pressure value is two times the free stream total pressure value.In order to provide maximum loading and lower weight of new aircraft inlet,the factors affected the engine surge over pressure were introduced such as pressure ratio.According to the experiment and evaluated analysis,the upper limit of hammer shock pressure ratio value was defined by the surge,which caused by the steady pressure distortion,and the maximum hammer shock loading was linearly increased by pressure ratio increase.The characteristics and evaluation curves of the hammer shock loading were analyzed.The results show that the problems of the loading inputs for aircraft design are solved by the ground test data of new engine and CFD,and the weight of composite S-shaped inlet duct is efficiently lowered by applying probabilistic method.