Experimental Study on the Control of Hovering Blade Tip Vortex by Blade Tip Combination Modification
Aiming at the control problem of hovering rotor blade tip vortex by blade tip shape,based on the step-by-step continuous segmentation method and polynomial curve fitting method,four types of rotor blade tips were designed by combining and modifying the blade tips.The effect of tip shape change on hovering rotor blade tip vortex control was investigated by using rotor balance and PIV testing technique.The results show that when the rotational speed is 550 r/min and the pitch angle is 11.3°,the three-dimensional blade tip with parabolic swept-back tapered anhedral can effectively suppress the flow intensity of the blade tip.The blade tip vortex circulation is reduced by 27.86％,the peak value of vorticity is reduced by 17.6％,the peak Q value is reduced by 26％,the peak value of the blade tip vortex induced upwash velocity is reduced by 75％,the peak value of the downwash velocity is reduced by 13％,and the tension coefficient decreases by 13％.The shape of the blade tip has little effect on the diameter of the vortex core,with a variation of less than 0.65％in the diameter of the vortex core.The control efficiency of blade tip shape is measured by the ratio of the change in tip vortex circulation to the change in tension coefficient,and the control efficiency of the three-dimensional tip with parabolic swept-back tip tapered anhedral can be more than 2.0.
RotorHovering statusBlade tip vortexTip shapeCombination and shapingControl efficiency
万方数据
维普
