考虑螺旋桨滑流的涡桨运输机失速速度的适航验证

Airworthiness verification of stall speed for turboprop transport aircraft considering propeller slipstream

涡桨运输机使用螺旋桨作为能量输出,滑流是螺旋桨飞机的重要特征,在适航验证时需考虑。失速速度是反映飞机气动特性的重要参数,在开展失速速度的验证时考虑滑流的影响尤为重要。分析了螺旋桨滑流对飞机气动特性的影响,根据涡桨运输机失速速度的适航规章条款CCAR25.103的相关要求,提出了涡桨运输机考虑滑流影响的失速速度的适航验证思路及具体的验证方法。以一型涡桨运输机滑流影响的风洞试验为例,给出了该型飞机在发动机慢车状态下,巡航构型时考虑滑流影响的纵向气动特性试验结果,试验结果进一步证明了在进行失速速度验证时考虑滑流影响的重要性,为失速试飞提供了依据。文中给出的验证方法为涡桨运输机的失速速度以及飞行性能和飞行品质相关的其它适航条款的验证提供了参考。

Turbopropeller powered transport aircraft uses propellers as energy output.Slipstream is an important feature of turboprop which should be considered in airworthiness verification phase.Stall speed is an important parameter to reflect aerodynamics characteristics of aircraft.It is particularly important to consider the influence of slipstream in the verification of stall speed.The influence of propeller slipstream on aircraft aerodynamic characteristics is analyzed.According to the relevant requirements of CCAR25.103,the airworthiness verification idea and specific verification method for the stall speed of turbopropeller powered transport aircraft considering the influence of slipstream are proposed.Taking the wind tunnel test on the influence of slipstream on a turboprop aircraft as an example,the test results of longitudinal aerodynamic characteristics of the aircraft under the condition of engine idle and cruising configuration considering the influence of slipstream are given.The test results further prove the importance of considering the influence of slipstream in stall speed verification,which can provide a basis for stall flight test.The verification method presented in this paper provides references for the verification of stall speed and other airworthiness provisions related to flight performance and flight quality of turbopropeller powered transport aircraft.