Purpose

This study aims to numerically investigate the multi-phase flow and thermal physics inside gearboxes, which is critical to the theoretical analysis of energy transfer.

Design/methodology/approach

To explore the churning power losses, a three-dimensional numerical model of the gearbox is built using the RNG k–e turbulence model and three alternative moving mesh strategies (i.e. the dynamic mesh [DM], sliding mesh and immersion solid methods). The influence of the rotational speed on the transient flow field, including the oil distribution, velocity and pressure distribution and the churning losses, is obtained. Finally, the time-dependent thermo-fluid state of the gearbox is predicted.

Findings

The findings show that the global DM method is preferable for determining the flow structures and power losses. The rotational speed exerts a significant effect on the oil flow and the wheel accounts for most of the churning losses. Based on the instantaneous temperature distribution, the asymmetric configuration leads to the initial bias of the high-temperature region towards the pinion. Additionally, the heat convection efficiency of the tooth tip is slightly higher than that of the tooth root.

Originality/value

An in-depth understanding of the flow dynamics inside the gearbox is essential for its optimisation to decrease the power and enhance heat dissipation during operation.

中文翻译：

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研究齿轮箱内油流的不同动网格策略的比较研究

目的

本研究旨在对齿轮箱内的多相流和热物理进行数值研究，这对于能量传递的理论分析至关重要。

设计/方法/方法

为了探索搅拌功率损失，使用RNG k-e 湍流模型和三种可选的移动网格策略（即动态网格[DM]、滑动网格和浸入固体方法）建立了齿轮箱的三维数值模型。得到了转速对瞬态流场的影响，包括油的分布、速度和压力分布以及搅拌损失。最后，预测了变速箱的时间相关热流体状态。

发现

研究结果表明，全局 DM 方法更适合确定流动结构和功率损失。转速对油流有显着影响，而车轮占大部分的搅动损失。基于瞬时温度分布，不对称配置导致高温区域向小齿轮的初始偏差。此外，齿尖的热对流效率略高于齿根。

原创性/价值

深入了解齿轮箱内部的流动动力学对于优化齿轮箱以降低功率并增强运行期间的散热至关重要。