环量控制机翼增升及滚转控制特性研究

Research on the lift-enhancement and roll control characteristics of a circulation control wing

环量控制作为一种高效的主动流动控制技术,在飞行器的气动改善、姿态控制方面具有巨大潜力。本文设计一套可以实现向下吹气的环量控制装置,并将其应用于飞行器进行气动控制。首先,通过数值模拟选取环量控制参数,同时分析环量控制翼型的气动特性。通过风洞实验,对同尺寸常规舵面模型和带有环量控制装置的模型进行气动力和气动力矩研究;采用粒子图像测速(PIV)技术,对环量控制模型开展流场研究,分析该装置产生气动控制效果的流动机理。测力实验表明吹气系数C_(μ)=0.04时,环量控制机翼升力最大增加32.4%,滚转力矩最大增加60.3%。PIV测流场实验表明,较高速度的射流使机翼后缘的气流发生了偏转,增加了环量,改变了机翼受力。引入"有效升阻比"的概念,分析环量控制机翼的吹气效率,结果表明,当吹气系数C_(μ)=0.02时,有效升阻比最大,环量控制机翼的吹气效率最高。

As an efficient active flow control technique,the circulation control has a great potential for aerodynamic improvement and performance enhancement of aircraft.Therefore,a set of circulation control devices that can blow downward are designed,and appllied for aerodynamic control of aircrafts.First of all,parametric analyses of aerodynamic characteristics of a two-dimensional airfoil are conducted by numerical simulations.Then,the aerodynamic force and moment of a conventional rudder wing and a circulation control wing of the same size are analyzed by wind tunnel experiments.Based on these results,the particle image velocimetry(PIV)is further used to reveal the mechanism of circulation control by characterizing the flow fields around circulation control devices.Wind tunnel experiments shows that,when the blowing coefficient equals to is 0.04,the lift coefficient and the roll moment coefficient increases by 32.4%and 60.3%,respectively.PIV results suggest that high-velocity jets deflects the airflow at the trailing edge of the wing,which consequently increases the amount of circulations and changes the force on the wing.The blowing efficiency of the circulation control wing is comprehensively analyzed by introducing the"effective lift-to-drag ratio".Results indicate that the largest effective lift-to-drag ratio and the highest blowing efficiency for a circulation control wing can be achieved with the blowing coefficient equals to 0.02.