Large-eddy simulations of the flow over an actuated NACA4412 airfoil at a chord-based Reynolds number ${\mathrm{Re}}_{\mathrm{c}}=400,000$ are conducted. These solutions extend the previous analysis of an actuated DRA2303 airfoil flow since both flow configurations possess completely different pressure distributions. The technique of spanwise traveling transversal surface waves is used to improve the aerodynamic efficiency, i.e., to decrease the drag and increase the lift. About 65% of the NACA4412 surface on the upper and lower side of the wing section are fully actuated. Two parameter combinations are tested, the first setup leads to an overall drag reduction of $\mathrm{\Delta }{c}_d=-8.3$% and an increase of the lift by $\mathrm{\Delta }{c}_l=2.4$% and the second combination yields a mild net power saving of $\mathrm{\Delta }{P}_{\mathrm{net}}=-1.4$%. Strong reductions of the wall-shear stress up to $\mathrm{\Delta }{c}_f=-31\%$ are achieved in the regions where the actuation parameters are optimum and the boundary layer growth is damped such that a reduced boundary layer thickness is observed at the trailing edge. Detailed boundary layer statistics are discussed for two positions on the suction and pressure side for both cases. The velocity fluctuations are strongly reduced across the boundary layer and a reduction of the streamwise fluctuations in the near-wall region is also observed in the problem specific inner scaling. Especially for the streamwise velocity a shift of energy away from the wall and from the smaller scales is obtained. The changes of the boundary layers persist beyond the actuated region, i.e., reduced turbulent kinetic energy is determined in the wake downstream of the trailing edge. The comparison of the actuated NACA4412 flow with data from an actuated DRA2303 flow shows similar modifications of the flow field, i.e., positive drag reduction is achieved for both airfoils. This clearly indicates the robustness of the transversal-traveling-wave drag reduction technique.

基于弦的雷诺数在驱动的NACA4412机翼上流动的大涡模拟 ${\mathrm{回覆}}_{\mathrm{C}}=400，000$进行。这些解决方案扩展了先前对DRA2303驱动翼型流的分析，因为两种流结构都具有完全不同的压力分布。跨展传播横向表面波技术用于提高空气动力学效率，即减小阻力并增加升力。机翼部分上，下侧的NACA4412表面的大约65％被完全驱动。测试了两个参数组合，第一个设置导致整体阻力降低了$\mathrm{\Delta }{C}_d=--8.3$％，提升量增加了 $\mathrm{\Delta }{C}_{升}=2.4$％，第二种组合产生的温和净功率节省为 $\mathrm{\Delta }{P}_{\mathrm{净}}=--1.4$％。大幅降低壁剪应力，直至$\mathrm{\Delta }{C}_F=--31％$在致动参数最佳并且阻尼边界层的生长的区域中实现了Δθ，从而在后缘观察到减小的边界层厚度。讨论了两种情况下吸入侧和压力侧两个位置的详细边界层统计信息。跨边界层的速度波动大大减小，并且在特定于问题的内部比例缩放中，还观察到了近壁区域中沿流方向波动的减小。特别是对于流向速度，可以获得远离壁和较小尺度的能量转移。边界层的变化持续到驱动区域之外，即，在后缘下游的尾流中确定了减小的湍动能。将驱动的NACA4412流量与驱动的DRA2303流量数据进行的比较显示出流场的相似变化，即，两个翼型均实现了正阻力减小。这清楚地表明了横向行波减阻技术的鲁棒性。