关键词: 阵风减缓, 合成双射流, 分离涡, 反向射流, 涡脱落

Abstract:

To study the gust alleviation strategy based on Dual Synthetic Jets （DSJ）， we arrange the actuators in an array on the upper surface of the NACA0012 airfoil， actively induce the flow separation through reverse jets， and study the evolution of the separated vortex and the dynamic vortex shedding， providing a new insight for load control based on the zero-mass jet. The results show that with the increase of the momentum coefficient C_μ， the control ability of DSJ over the gust load is gradually improved without causing large fluctuation of the lift coefficient C_L . At C_μ = 0.033， the trailing edge separation zone develops to the middle position of the airfoil， and the response amplitudes of C_L，max decrease by 47.9%. Because of the large separation zone at the trailing edge， the unloading process of the separated vortex on the upper wing surface after closing the jet actuator will have a significant impact on C_L . In the process of airflow impacting the separated vortex， the pressure difference between the upper and lower wings rapidly increases， leading to rapid decrease of C_L . Then， aiming at this process， we study the C_μ step-decreasing control， and set the C_μ interval change. Compared with the case of continuously applying constant C_μ， this control method requires less energy consumption in achieving the same slowing amplitude， and the airfoil also spends less time under high load impact.

Key words: gust alleviation, dual synthetic jets, separated vortex, reverse jet, vortex shedding