Numerical Study on Flow Characteristics of Airfoil With Bionic Micro-Grooves

Abstract

For the purpose of exploring the influence of the location of the bionic micro grooves on the flow characteristics of the airfoil, three airfoil models with bionic grooves were established according to the different positions of the bionic grooves. Large eddy simulation is used to numerically simulate the flow of different airfoils. Compared with the smooth airfoil, the flow characteristics and aerodynamic performance parameters of the bionic micro-groove airfoil are analyzed at 6° angle of attack, 24 m/s and 30 m/s speed. The results show that the three types of bionic grooved airfoil suppress the thickness and flow length of the separation zone, making the reattachment position of the separation zone more forward than that of the smooth airfoil, thus having different degrees of separation of the airfoil surface boundary layer. Control effect. In addition, the existence of bionic micro-grooves reduces the vortex structure in the near-wall zone, reduces the center height of the separation zone, and reduces the normal velocity gradient, which weakens the energy dissipation in the flow. Airfoil-H1 airfoil has the best flow characteristics and aerodynamic performance at 24 m/s, the drag reduction rate is the largest, reaching 16.99%, and the lift-to-drag ratio increases by 16.34%. The Airfoil-H2 airfoil has the best effect at 30 m/s, the drag reduction rate is the largest, reaching 18.09%, and the lift-to-drag ratio increases by 18.86%. Airfoil-H3 airfoil has a lower effect, but the effect becomes more pronounced as the speed increases. As the mainstream speed increases from 24 m/s to 30 m/s, the optimal airfoil will gradually transition from Airfoil-H1 airfoil to Airfoil-H2 airfoil regardless of flow characteristics or aerodynamic performance parameters. It is found that there is the best matching value between the location of the bionic groove and the mainstream speed, so that the groove can play the best improvement effect.