The investigation of flow separation control over a NACA 0015 airfoil model using a fluidic oscillator (FO) is conducted through delayed detached eddy simulation. First, the flowfield within and outside an FO operating in quiescent air is resolved simultaneously. The oscillation of the jet flow induced by the FO is attributed to the cyclic expansion and contraction of the recirculation bubbles located near the two Coanda surfaces in the mixing chamber. Significantly, the predicted jet oscillation frequency closely matches the experimental data, validating the accuracy of our findings. Next, the FO is integrated into an airfoil model to suppress the flow separation. The airfoil is under deep stall conditions, with angles of attack of 20 and 17° and a Reynolds number of $Re=4.8\times {10}^5$. The key driving force for flow reattachment is the spanwise vortices induced by the oscillating jet, which substantially enhance the mixing between the separated flow and the external high-momentum flow. Consequently, the aerodynamic performance of the airfoil is notably improved. Additionally, both spectral and dynamic mode decomposition analyses indicate that the flow, under the influence of the FO forcing, becomes more orderly and well-organized and is effectively locked into the forcing frequency.

通过延迟分离涡模拟对使用射流振荡器 (FO) 的 NACA 0015 翼型模型进行流动分离控制的研究。首先，同时解析在静态空气中运行的 FO 内部和外部的流场。 FO 引起的射流振荡归因于位于混合室中两个柯恩达表面附近的再循环气泡的循环膨胀和收缩。值得注意的是，预测的射流振荡频率与实验数据非常吻合，验证了我们研究结果的准确性。接下来，将 FO 集成到翼型模型中以抑制流动分离。机翼处于深度失速状态，迎角为 20° 和 17°，雷诺数为$右e=4.8\times {10}^5$。流动重新附着的关键驱动力是振荡射流引起的展向涡流，它大大增强了分离流与外部高动量流之间的混合。因此，翼型的气动性能显着提高。此外，频谱和动态模式分解分析表明，在 FO 强迫的影响下，流动变得更加有序和组织良好，并且有效地锁定到强迫频率。