Oil Splashing Simulation Of Single Stage Gear Based On CFD

As one of the most important components in the automobile transmission system,gearbox have an impact on the car’s performance, fuel economy, manipulability,transmission stability, efficiency of transmission and so on.Whether the performance ofgearbox is good or bad has a direct relationship with its lubrication condition. As part ofit, the research of gear and bearing lubrication is of great practical value.The interior structure of gearbox is complex, containing a large number of gearsand shaft. In this paper, the gearbox interior space is abstract as the representative of asingle stage gear and a rectangle. Aimed at finding the advantages and disadvantages,characteristics and practicability of different simulation methods, using the immersedsolid method and RFR provided by CFX, and dynamic grid method provided byFLUENT simulates the internal flow field under the similar boundary condition anddoes comparison research. Finally provide valuable reference and suggestion for thesimulation of internal flow of the gearbox. Based on the former representation, I didsome work and got some conclusions as follows:Based on the immersed solid method，RFR and dynamic grid methodcombiningwith the VOF model established simulation model of single stage gear lubrication. Afterthe solving was completed, analyzed results from the flow regime, velocity distribution,oil volume fraction distribution and so on.In the end, I make comparison and summaryof different methods based on the simulation results. The immersed solid method ownsadvantage in the velocity field simulation andthe iterative convergence is rapid, but thesimulation of heat transfer is difficult. RFR method results in a large distance betweentwo engaged gears, because this method require such geometric model modification.While the trend of the oil flowing is correct but has some difference on the distributionof oil with a correct model. Dynamic grid method is more ideal, and can do heat balancecalculation. Recommending adopt the dynamic grid method transmission for thecalculation of this method for the simulation of internal flow of the gearbox, but shouldfocus on the contradiction among the calculation accuracy, grid size and computationtime.