以无人直升机传动系统的减速器机匣为研究对象,建立了其热-流-固耦合仿真计算模型,基于Fluent软件对减速器舱内的流场及温度场进行了数值仿真。本文分析了前进气口气流速度与方向、侧排气口位置、以及散热片数量与位置对机匣散热能力的影响。结果表明,随着气流速度的增加,机匣壁面温度分布规律一致,但整体散热性能增强；进风口气流方向能直接改变舱内流场,从而对机匣外壁温度分布产生显著的影响；侧排气口位置能改变舱内气流分布,进而间接影响机匣壁面的温度场；在机匣表面附加散热翅片能显著降低机匣壁面温度,改善机匣散热性能。仿真研究结果为减速器研制阶段确定机匣散热占比,进风口风道设计、选择散热片位置、及排风口布置提供依据。

Taking the reducer casing of unmanned helicopter transmission system as the research object, the thermal-fluid-solid coupling calculation model is established. The flow field and temperature field in the reducer cabin is simulated based on Fluent. The effects of the airflow velocity and direction of the front air-inlet, the position of the side vent, and the number and position of the heat sink on the heat dissipation Performance of the casing are analysed. The results show that, with the increase of airflow velocity, the temperature distribution pattern of the casing wall is consistent, but the overall heat dissipation performance is enhanced; the airflow direction of the air inlet can directly change the flow field in the cabin, which significantly affects the temperature distribution of the outer wall of the casing; the position of the side vent can change the airflow distribution in the cabin, which indirectly affects the temperature field on the wall of the casing; and the the additional cooling fins on the casing surface can significantly reduce the temperature of the magazine wall and improve the thermal performance of the casing. The simulation results provide a basis for determining the percentage of heat dissipation in the casing, selecting the location of the heat sink, designing the of air-inlet, and arranging the side vent during the development stage of the gearbox.

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重庆市杰出青年科学基金项目CSTB2022NSCQ-JQX0026