CFD Simulation for Reduction of Oil Churning Loss and Windage Loss on Aeroengine Transmission Gears

Abstract

In recent years, the demand for power generation capacity has increased considerably due to the electric drive of air conditioners and so on in the engines of civil aircraft. Therefore, it is estimated that power losses may increase in the gearbox because of generators and pumps that in turn augment fuel consumption. To understand the phenomena of losses in the gearbox and to reduce these losses, Computational Fluid Dynamics (CFD) simulation that analyzes oil churning loss and windage loss was developed and improvements were made to the shroud of bevel gears. The CFD agreed with experimental results on a bevel gearbox of a 100-seater aircraft. And, it was shown that the suppression of momentum transfer from the rotating gears to oil clusters is of importance. In addition, it was revealed that the loss was reduced up to 36% compared to non-shrouded gears by shrouding in the experiments. This CFD simulation can be applied to many types of gearboxes that have spur gears, bearings and seals.