Abstract
The increasing demand of more and more efficient gearboxes implies the need of predictive models. Models provided by literature for load independent power losses are mainly based on experimentally derived relations that are not so accurate on real applications. A new trend suggests to use CFD for the calculation of the no-load losses of gear transmissions. In this sense, literature provides some works but most of them involve only one single phase. In this paper, some investigations of both the oil-windage losses and the churning losses in which the gears are immersed in an air/oil lubricant mixture are studied. Furthermore, some attempts to reduce the computational effort have been successfully tested.