Research Topic
| Short Title | Windage Power Loss Planetary Gearboxes |
| Start of Project | Q4/2024 |
| Funding | FVA-Nr. 1014/I Research Association for Drive Technology e.V., FVA |
| Contact | Dr.-Ing. T. Lohner |
Project Description
The aim of the research project is to develop an analytical and easy-to-use calculation equation for the windage power loss of high-speed injection-lubricated planetary gearboxes. The windage power loss represents a significant proportion of the total gearbox power loss at the resulting high circumferential speeds. Existing analytical calculation equations for the windage power loss were derived from tests with single-stage gearboxes with cylindrical gears and only show a limited quality of results for high-speed planetary gearboxes. In this research project, computational fluid dynamics (CFD) is used to calculate the fluid flow (see figure 1) and windage power loss.
As a result of the research project, a practical analytical calculation equation for the windage power loss of high-speed planetary gearboxes will be developed. To this end, data from the literature will first be recalculated using various calculation approaches in order to evaluate existing approaches. In parallel, data from the literature is recalculated using numerical flow simulation in order to validate a CFD simulation setup for calculating the windage power loss. The Finite Volume Method (FVM) (see figure 2) and the Smoothed Particle Hydrodynamics (SPH) method are considered. The windage power loss of high-speed planetary gearboxes are then predicted using the more promising CFD method and compared with practical data. In this way, relevant variables for the windage power loss can be derived and transferred to an analytical calculation model, whereby an increased prediction accuracy is expected.
Accurate analytical calculation approaches are particularly relevant for small and medium-sized enterprises (SMEs) in the field of high-speed planetary gearbox development. The results of the project make it possible to shorten development processes for specific new applications, reduce development risks and cut costs. This can increase the competitiveness of the SMEs involved. A better understanding of the windage power loss also contributes to the development of more efficient gearboxes.
Literature
[Liu18a] Liu, H.; Jurkschat, T.; Lohner, T.; Stahl, K.: Detailed Investigations on the Oil Flow in Dip-Lubricated Gearboxes by the Finite Volume CFD Method. Lubricants 6. Heft: 2, S. 47 (2018).
[Liu18b] Liu, H.; Standl, P.; Sedlmair, M.; Lohner, T.; Stahl, K.: Efficient CFD Simulation Model for a Planetary Gearbox. Forschung im Ingenieurwesen 82. Heft: 4, S. 319– 330 (2018).