External airborne installations of cylindrically-shaped objects, such as turrets, can lead to severe degradation of flight performance. This engineering challenge is mainly due to an unsteady and separated vortex flow field that evolves in the wake downstream of the turret. This study focuses on providing an engineering solution to attenuate the wake unsteadiness. Experiments were performed in the Israeli Air Force (IAF) low speed wind tunnel, where we investigated various passive flow control methods on a hemispherical dome attached to a cylindrical body turret with a low aspect ratio (AR) of 1.36 at a diameter-based Reynolds number of $R{e}_D=3.75\times {10}^5$. Three modifications of the baseline turret geometry were examined. The configurations include the addition of a grit roughness strip, a turbulator zigzag trip tape, and a straight edge protuberance (or a bump strip). The velocity fields in the near wake downstream of the various turret configurations were acquired using a particle image velocimetry (PIV) technique. Results show that tripping the flow using a bump strip is the most effective for the turret studied herein. The bump strip prompts symmetrical vortex shedding downstream, which can potentially eliminate the fluctuating side force on the turret, while also contributing the least to any drag increase (or penalty). Implementing such a passive flow technique on cylindrical installations may assist in resolving large fluctuating side forces and meeting operational requirements during flight.

圆柱形物体（例如炮塔）的外部机载装置会导致飞行性能严重下降。这一工程挑战主要是由于在炮塔下游尾流中形成的不稳定和分离的涡流流场。这项研究的重点是提供一种工程解决方案来减弱尾流不稳定性。在以色列空军 (IAF) 低速风洞中进行了实验，我们在基于直径的雷诺数下研究了连接到圆柱体转塔上的半球形圆顶上的各种被动流动控制方法，该转塔具有 1.36 的低纵横比 (AR)数量$\mathrm{电阻}{\mathrm{电子}}_D=3.75\times {10}^5$. 检查了基线炮塔几何形状的三个修改。配置包括添加粗砂条、湍流器之字形绊带和直边突起（或凹凸条）。使用粒子图像测速 (PIV) 技术获取各种炮塔配置下游近尾流中的速度场。结果表明，对于此处研究的转塔，使用缓冲带阻止流动是最有效的。碰撞带促使下游对称的涡流脱落，这可能会消除炮塔上波动的侧向力，同时对任何阻力增加（或惩罚）的贡献最小。