With the widespread of spiral bevel gears in aero-engines applications, it becomes a burning challenge to reduce the windage power loss owing to the high-speed rotation of these gears. As shrouding the gears has been manifested as an effective approach to reducing windage power losses and restricting the flow in the vicinity of gear teeth, a shroud in this paper is introduced to enclose the high-speed unmeshed spiral bevel gear. By leveraging the CFD software and selecting multi reference frame (MRF), the windage behavior of our proposed model is evaluated and compared with that without a shroud, and the influence of rotational speed of the bevel gear on windage power loss is also analyzed. Furthermore, further attention has been paid to the effects of the spacing between the bevel gear and the shroud. including the toe clearance, the face clearance and the heel clearance. Simulation results demonstrate that the windage power loss dramatically increases with the increment of the gear speed, and the windage power loss of the enclosing bevel gear declines rapidly by 80 percent relative to the bevel gear without a shroud. Moreover, it observes that the trend of windage power loss reducing with the decreasing spacing between the shroud and the bevel gear, finding the optimal spacing. This paper provides prerequisites towards pursuing the researches on the windage loss of meshing spiral bevel gears under oil-jet lubrication.

随着螺旋锥齿轮在航空发动机应用中的广泛应用，减少由于这些齿轮的高速旋转而造成的风阻功率损失已成为一项迫在眉睫的挑战。由于罩齿轮已被证明是减少风阻功率损失并限制轮齿附近流量的有效方法，因此本文引入了一种罩来封闭高速未啮合的螺旋锥齿轮。通过使用CFD软件并选择多参考系（MRF），我们对所提出模型的风阻行为进行了评估，并将其与无护罩的风阻行为进行了比较，并分析了锥齿轮转速对风阻功率损耗的影响。此外，锥齿轮和护罩之间的间隔的影响已经引起了更多关注。包括脚趾间隙，面部间隙和脚跟间隙。仿真结果表明，风阻功率损耗随齿轮转速的增加而急剧增加，而封闭式锥齿轮的风阻功率损耗则相对于没有护罩的锥齿轮迅速下降了80％。此外，它观察到风阻功率损失的趋势随着护罩和锥齿轮之间的间距减小而减小，从而找到了最佳间距。本文为进一步研究油润滑下啮合螺旋锥齿轮的风阻损失提供了前提。相对于没有护罩的锥齿轮，封闭锥齿轮的风阻功率损失迅速降低了80％。此外，它观察到风阻功率损失的趋势随着护罩和锥齿轮之间的间距减小而减小，从而找到了最佳间距。本文为进一步研究油润滑下啮合螺旋锥齿轮的风阻损失提供了前提。相对于没有护罩的锥齿轮，封闭锥齿轮的风阻功率损失迅速降低了80％。此外，它观察到风阻功率损失的趋势随着护罩和锥齿轮之间的间距减小而减小，从而找到了最佳间距。本文为进一步研究油润滑下啮合螺旋锥齿轮的风阻损失提供了前提。