地效对飞机气动特性的影响研究

当飞机起飞或着陆时由于近地会产生地面效应。地效使得飞机的气动特性发生较大变化,如升力增大、阻力减小及静安定度的提高等。通过试验数据分析了地效状态下纵、横航向气动特性及舵效的变化,并对其内在影响机理进行了初步分析。结果显示,地效使得着陆构型失速提前约2°、纵向静安定度增加约0.15bA、横向安定性增加约10%~20%、平尾效率减小可达10%、方向舵效率变化较小但副翼效率减小可达10%。由此使得飞机的失速特性、横航向稳定性及操纵性变差。

The Study of the Ground Effects on the Aircraft Aerodynamic Characteristics

As an aircraft takeoff or landing, the aerodynamic characteristics change a lot for the ground effect,such as lift/ stability increasing and drag reducing etc. This paper analyzes the change of the longitudinal/lateral characteristics and maneuvering surface efficiency, and also tries to analyze the mechanism of the ground effect.Results show that, with ground effect, the stall happens 2° earlier, longitudinal stability increases 0.15 bA, lateral stability increases 10%~20%, horizontal tail efficiency increases 10%, rudder efficiency changes little while the decrease of the aileron efficiency can reach 10%. Due to these effects, stability and maneuvering ability of the aircraft are deteriorated.