Numerical Simulation Investigation on the Windage Power Loss of a High-Speed Face Gear Drive

Yu Dai,Feiyue Ma,Xiang Zhu,Jifu Jia

doi:10.3390/en12112093

Abstract

Reducing the energy consumption and improving the efficiency of high-speed transmission systems are increasingly common goals; the windage power loss is not negligible in these methods. In this work, the multi-reference frame (MRF) and periodic boundary conditions (PBC) based on the computational fluid dynamics (CFD) method were adopted to investigate the windage phenomena of a single face gear with and without a shroud, and the impact of the gear speed on the windage power loss was analyzed. Furthermore, the effects on the distribution of static pressure due to the distances between the shroud and the gear body in different directions, including the outer radius direction, the inner radius direction, and the addendum direction were investigated. The results indicate that the gear speed significantly affected the windage loss, as the higher the gear speed was, the greater the windage power loss. Additionally, the shroud could effectively reduce the windage power loss, where the optimal distance from the addendum to the shroud was not the minimum distance; however, for the distances from the shroud to the inner radius and the outer radius, the smaller the distance was, the smaller the windage loss. The results can provide a theoretical basis and technical reference for reducing the windage power loss of various face gear drives.

Highlights

All rotating machinery will stir up the surrounding air, resulting in windage power loss, restricting fuel economy and reducing transmission efficiency, especially for aeronautical transmission systems.The face gear drive is a new kind of meshing transmission between a cylindrical gear and a bevel gear, which has been successfully applied in the main reducer of armed helicopters owing to its numerous advantages [1,2,3,4]
To observe the windage phenomenon more clearly, two planes named as Section 1 and Section 2
2the were made on the gear body, as shown in Section was the middle plane that tooth space and passes though the axis, and Section 2 was parallel to the surface of the addendum bisects tooth to space and passes was though axis, Section

Summary

Introduction

All rotating machinery will stir up the surrounding air, resulting in windage power loss, restricting fuel economy and reducing transmission efficiency, especially for aeronautical transmission systems.The face gear drive is a new kind of meshing transmission between a cylindrical gear and a bevel gear, which has been successfully applied in the main reducer of armed helicopters owing to its numerous advantages [1,2,3,4]. All rotating machinery will stir up the surrounding air, resulting in windage power loss, restricting fuel economy and reducing transmission efficiency, especially for aeronautical transmission systems. The efficiency of a well-designed gearbox can reach 99%, the power loss cannot be neglected in high-power applications. Due to the working conditions under ultra-high speed, the contact area between the face gear and the surrounding air increases, which intensifies the pressure difference between the tooth surfaces and produces a resistance moment opposite to the face gear’s rotation; all of these factors will lead to the increase of the windage power loss of face gears. It is necessary to investigate the windage power loss of the face gear rotating in the air and explore effective methods to reduce energy loss, so as to improve the performance and expand the engineering application of the face gear drives

Methods

Results

Conclusion