翼型绕流不同频率展向振荡电磁力减阻控制实验研究

研究结果表明展向振荡电磁力可控制湍流边界层,电磁力的振荡频率对湍流的控制效果有影响,但并未讨论电磁力振荡频率对控制效果的影响机理。实验研究了不同频率展向振荡电磁力控制翼型绕流的减阻效果及其影响机理。实验在转动的水槽中进行,在翼型的背风面包覆展向振荡电磁力激活板,并将其浸入水槽中,利用应变传感器测量翼型的阻力,基于意法半导体公司生产的微处理器开发电磁力控制器,用于控制电磁力的方向和振荡频率。研究结果表明展向振荡电磁力对翼型绕流具有减阻效果,对比分析了不同频率的展向振荡电磁力的减阻效果,发现电磁力的振荡频率为20 Hz时减阻效果较优,减阻效率可达到18%;展向振荡电磁力可减小翼型阻力的振动幅值,具有减震功能;当电磁力的振动频率与阻力曲线内小波动频率相近时,电磁力的减阻减震的效果最佳。

Experimental Study on Drag Reduction Control of Oscillating Electromagnetic Force with Different Frequency in Flow Around Airfoil

A great number of studies have showed that the oscillating electromagnetic force can control the turbulent boundary layer, and the oscillation frequency of the electromagnetic force has an effect on the control effect of turbulent flow. However, the influence mechanism of the frequency of the electromagnetic force on the control effect has not been discussed. In this paper, the drag reduction effect and its influencing mechanism of airfoil flow controlled by oscillating electromagnetic force at different frequencies are experimentally studied. The experiment was carried out in a rotating water tank. The oscillating electromagnetic force activation plate was coated on the lee side of the airfoil, and was immersed in the water tank. The resistance of the airfoil was measured by a strain sensor, and an electromagnetic force controller developed based on the microprocessor produced by STMicroeletronics was used to control the direction and frequency of the electromagnetic force. The results show that the spanwise oscillating electromagnetic force has a drag reduction effect on the airfoil flow, and the drag reduction effect is better when the electromagnetic frequency is 20Hz, and the efficiency can reach 18% by comparing and analyzing the drag reduction effect of the spanwise oscillating electromagnetic force at different frequencies; the spreading oscillating electromagnetic force can reduce the vibration amplitude of the airfoil resistance, and when the electromagnetic vibration frequency is close to the small fluctuation frequency in the resistance curve, electromagnetic force has the best effect of drag reduction and damping.