Enhancing the efficiency of gear systems is of significance to reduce fuel consumption and overall weight. Windage power losses become prevailing in high-speed gear systems, such as aero-engine applications. To avoid the shortages and limitations of commonly used methods (e.g. negative volume in dynamic mesh method and one moving object in sliding meshing method), this paper describes an unstructured overset computational fluid dynamics technology to simulate the airflow pattern in a gearbox and calculate the windage losses. A disk, a spur gear and a helical gear, spinning in the air at rotational speed up to 7200 r/min are studied respectively, the windage power losses obtained by the numerical method show good agreement with experimental data and analytical findings in the open literature. Meanwhile, the associated deceleration torques exerted by pressure and viscous forces on spinning gear surfaces are also determined. Furthermore, the overset method facilitates to estimate the windage losses of a non-meshing gear pair. The results of this paper indicate that the overset method can accurately predict the windage power losses and provide a new route to investigate the flow pattern surrounding the gears. This method can serve as an effective tool for engineering applications in the future.

提高齿轮系统的效率对减少燃油消耗和总体重量很重要。风速功率损耗在诸如航空发动机应用的高速齿轮系统中变得普遍。为了避免常用方法的不足和局限性（例如，动态啮合方法中的负体积和滑动啮合方法中的一个运动对象），本文介绍了一种非结构化的溢流计算流体动力学技术，用于模拟变速箱中的气流模式并计算风阻损失。分别研究了在空气中以最高7200 r / min的转速旋转的圆盘，正齿轮和斜齿轮，通过数值方法获得的风阻功率损耗与实验数据和公开文献中的分析结果显示出良好的一致性。 。与此同时，还可以确定由压力和粘性力作用在旋转齿轮表面上的相关减速扭矩。此外，超速方法有助于估计非啮合齿轮对的风阻损失。本文的结果表明，超限法可以准确预测风阻功率损失，并为研究齿轮周围的流型提供了新的途径。这种方法可以作为将来工程应用的有效工具。本文的结果表明，超限法可以准确预测风阻功率损失，并为研究齿轮周围的流型提供了新的途径。这种方法可以作为将来工程应用的有效工具。本文的结果表明，超限法可以准确预测风阻功率损失，并为研究齿轮周围的流型提供了新的途径。这种方法可以作为将来工程应用的有效工具。