CFD modelling and numerical simulation on windage power loss of aeronautic high-speed spiral bevel gears

Abstract

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.