March 6 - 8, 2017 | Berlin
LEADING ENGINEERING SIMULATION CONFERENCE
The reduction of CO2 emissions is one of the biggest challenges to the automotive industry. An optimally designed driveline with effective cooling and lubrication provides substantial CO2 reduction. The cooling and lubrication performance is critical to the functionality and durability of vehicle drive units, such as transmissions and differentials. Final drive includes gears, bearings and shafts to transmit power from the engine to the wheels. Final Drives rely on splash lubrication where the oil flow is driven by the rotation of the gears and guided to important positions. Splash lubrication is difficult to predict due to the chaotic nature of the flow, and therefore development of the lubrication system is still done experimentally in rig tests. The use of CFD simulation with high-performance computing has made it possible to predict and optimize the oil lubrication and cooling performance of final drive.
The CFD method is developed that includes transient multiphase flow (oil and air) simulation using Volume of Fluid method (VOF) and Overset grid. The gear interaction is modeled while by Overset grids, simultaneously modeling fluid interaction with the gears. The CFD method is validated with the experimental results of oil splash visualisation and churning losses in final drive housing. The developed CFD method is an effective way to evaluate more design alternatives e.g. gear designs, optimized oil quantity and flow at different locations. It can be useful in the early stages of the product development process.