Despite their advantages compared to hydraulic actuators, electric actuators are prone to overheating due to their high heat dissipation. So, developing reliable cooling systems for electric actuators is a crucial task, especially for aerospace applications which require the fulfillment of high safety requirements. In this paper, an air-cooling system utilizing wing bay air is investigated. An axial fan sucks air to flow through a shrouded-fin surface attached to the motor housing. A CFD model is developed to study the heat transfer and air flow processes over the finned surface. The relation between the fan pressure jump with the volumetric flow rate of a high speed SUNON fan at different rotational speeds and ambient pressures is measured in a fan loop and incorporated in the model. To validate the CFD results, a test rig consisting of a finned surface brazed on a heated aluminum cylindrical block and attached to a fan is built. The predicted and measured temperatures at different locations in the aluminum block show good agreement when the numerical simulation is performed using the k-ω-SST turbulence model. The average discrepancy of the predicted and measured steady state temperature differences (T-T_∞) reduces from 1.6 °C for the k-ε Realizable model to 0.31 °C for the k-ω SST model. Numerical simulation is performed to predict the effect of fin shape, fin number and fin thickness on the cooling performance of the fin structure. The results show that the straight plate fin configuration outperforms the offset-strip and corrugated fin. Also, it is found that there is an optimum value for the fin number, and this optimum fin number changes with the fan rotational speed and ambient pressure. Reducing the solidity of the fin structure by reducing the fin thickness results in improving the thermal performance when the fan operates at a low ambient pressure (0.2 atm). By comparing all data, it is found that the straight fin structure with 110 fins and fin thickness 0.2 mm is the optimum one. For fan speed of 12,000 rpm, this structure can restrict the thermal resistance between 0.17 °C/W at 0.2 atm and 0.047 °C/W at 1.0 atm.

尽管与液压执行器相比有其优势，但电动执行器由于其高散热性而易于过热。因此，为电动执行器开发可靠的冷却系统是一项至关重要的任务，特别是对于要求满足高安全性要求的航空航天应用而言。本文研究了一种利用机翼舱空气的空气冷却系统。轴流风扇吸入空气，使空气流过连接到电动机壳体的带罩翅片表面。开发了一个CFD模型来研究翅片表面的传热和空气流动过程。在风扇回路中测量了风扇压力跳跃与高速SUNON风扇在不同转速下的体积流量和环境压力之间的关系，并将其纳入模型中。为了验证差价合约结果，建造了一个试验台，该试验台由钎焊在加热的铝制圆柱体上并连接到风扇的翅片表面组成。当使用k-ω-SST湍流模型进行数值模拟时，铝块中不同位置的预测和测量温度显示出良好的一致性。预测和测量的稳态温差（TT的平均差异）_∞）用来降低从1.6  ℃下为的k-ε可实现模型到0.31  ℃下为K-ωSST模型。进行数值模拟以预测翅片形状，翅片数量和翅片厚度对翅片结构的冷却性能的影响。结果表明，直板翅片的性能优于偏置条和波纹状翅片。而且，发现鳍片数量存在最佳值，并且该最优鳍片数量随风扇转速和环境压力而变化。当风扇在低环境压力（0.2个大气压）下运行时，通过减小散热片厚度来减小散热片结构的坚固性可改善热性能。通过比较所有数据，发现具有110个鳍片且鳍片厚度为0.2mm的直鳍片结构是最佳的。对于12,000 rpm的风扇速度，此结构可以将热阻限制在0.17  °C / W之间在0.2 atm和0.047  °C / W在1.0 atm下。