Numerical simulation and test on two-phase flow inside shell of transfer case based on fluid-structure interaction

作者：Chen, Liqing^*; Zhang, Dong; Chen, Wuwei

来源：Transactions of the Chinese Society of Agricultural Engineering, 2014, 30(4): 54-61.

DOI：10.3969/j.issn.1002-6819.2014.04.008

• Dynamic mesh
• Fluid pressures
• High-speed motion
• Negative pressures
• Pressure field
• research methods
• Tooth surface
• Two-phase model

In order to investigate the characteristics of air-oil two-phase turbulent flow inside the shell of transfer case, the research method to combine test and numerical simulation is proposed to take analysis. The fluid-structure interaction theory (FSI) is a science to research the interaction and influence between fluid and structure fields, and is applied to research single-direction influencing characteristic from gears rotation to air-oil field flow. The gears of the transfer case transfer power via meshing and rotating, their movement is imitated by dynamic mesh technology is fluent. Fluent UDF definition is used to define the parameters of dynamic mesh control. The fluid field inside the shell of the transfer case has two phases: air and oil. It starts to move and show its fluid characteristics in close relationship with the motion trail of gears. The air-oil fluid field belongs to a two-phase model. It is simulated by the VOF model is fluent. The interface of gas and liquid is defined by fluent UDF definition. High speed photography is the application of advanced photographic technology for high-speed motion characteristics of a clear picture. It is used to observe high-speed motion characteristics. With a transparent shell, the transfer case assembly is installed on the test bench for the observation test. The movement of air-oil fluid field has been observed after high speed photography. The results show that, during 0-0.5T moment, driven gear to rotate with oil plays a main role in the meshing zone lubrication; at 0.25T moment, gears start to mesh and rotate, oil fluid field wave; at 0.375T moment, the gear meshing area is filled with lubricating oil; at 0.5T moment, the continuous oil inflow meshing zone above, and cover the gear meshing area of tooth surface, achieve initial lubrication. The vortex phenomenon appears near the meshing zone in the velocity streamline. The speed near the wall is higher than the other zone. The velocity streamlines into and out of the meshing zone more effectively. After the pressure field stabilizes, the flow field pressure maximum value appeared in the gear meshing area; two phases of flow field in the shell are uniform, the middle of the fluid pressure is relatively small; negative pressure appears below the driven gear part. The numerical simulation results coincide with the test. The analysis results are true and valuable.

• 出版日期2014
• 单位合肥工业大学