Zur numerischen Simulation der Ölstrahl-Zahnrad-Interaktion in Flugtriebwerken

Abstract

The geared turbofan engine is seen as a short-term response to economic, ecological and societal demands for efficient and quiet propulsion systems in civil aviation. For this jet engine architecture, optimization of the oil system in the integral ultrahigh-power gearbox is essential, in particular with regard to its cooling function. Previous studies have shown that the oil distribution over the tooth flanks resulting from the oil jet-gear interaction (OGI) plays an important role for the cooling effect achieved by means of oil-jet lubrication. However, to date there is no suitable analytical or experimental methodology for quantitative analysis of the OGI, which is why its characterization is incomplete. This work aims to address this point. By means of computational fluid dynamics (CFD), the OGI is made accessible. Here, the grid-based volume of fluid (VOF) method and, for the first time, the particle-based smoothed particle hydrodynamics (SPH) method are used. The latter promises to overcome limitations of grid-based methods in modeling the gear motion -in particular the gear meshing -and the complex oil/air two-phase flow.