微型涡流发生器控制增升装置流动分离研究

Controlling Flow Separation of High Lift Transport Aircraft with Micro Vortex Generators

针对大型飞机增升装置大偏度状态出现的流动分离问题,采用数值模拟方法,研究使用微型涡流发生器控制其附面层分离的作用机理及流动控制效果。结合风洞实验结果,验证了数值方法的可靠性,并以某型号运输机二维增升构型为对象,系统分析了微型涡流发生器尺寸、安装角、安装位置、排列方式等参数对其流动控制效能的影响规律,获得了设计原则,给出了流动控制方案,为实现三维增升装置流动分离控制的微型涡流发生器研究奠定了基础。

The operating mechanism and the influences of parameters of micro vortex generators in controlling flow separation of high lift transport aircraft are investigated in this paper. Section 1 of the full paper explores the operating mechanism. After researching with computational fluid dynamics the influences of a series of parameters including size（ subsection 3.1 ） , fixing angle（ subsection 3.2）, fixing position（ subsection 3.3 ）and fixing way（ subsection 3.4）, we obtain the design principles as follows ： （ 1 ） the principle of controlling flow separation is to inject vortices to the bottom of boundary layer; （2） as the fixing angle decides vortex strength and drag, it has to be chosen properly; （3） vortex generators should be fixed before separation point but as close to it as possible; （4） counter-rotating vortex generators have better control efficiency than co-rotating vortex generators. Based on these principles, subsection 3.5 offers a control scheme to improve the lift performance of a 4-element airfoil ： （ 1 ） Fig. 11 shows that we successfully eliminate the flap separation of take-off and landing configurations at angle of 0°- 14°; （2） at α =8°, δf =25°, the lift is increased by 14%, L/D increased by 30% （Fig. 12） ; （3） at α = 10°, δf =50°, the lift is increased by 24% , L/D increased by 34% （Fig. 12） ; （4） micro vortex generators cannot improve stall characteristics because the flow separation happens at main wing and, in this case, the micro vortex generators are already immersed into the wake and have no effect.