Research On Air-liquid Two-phase Flow And Fluid-solid Coupled Heat Transfer In Rotating Disk System

The rotating disk flow is a very important basic flow,which constitutes the theoretical basis of the fluid flow in much disk fluid machinery.It has been widely used in energy,aerospace,vehicle,medical and chemical fields.In the wet clutch,hydro-viscous drive and other key transmission components,there are complex interactions of force and heat between the oil and disk structure,which has a direct impact on the efficiency and reliability of the transmission system.The fluid flow and heat transfer between disks are studied in this paper.It aims to propose a basic method to investigate the fluid flow and heat transfer in the disk fluid machinery.The method can provide a theoretical basis for further improving the efficiency of the transmission system and optimizing the design of the lubrication system.The flow visualization method was used to study the gas-liquid two-phase flow pattern in rotating disk system.A flow pattern visualization test rig is set up to obtain the flow structure of gas-liquid two-phase flow directly.The obtained flow structures are divided into several typical flow patterns.The flow characteristics of each flow stage are discussed in detail,and the oil volume fraction of the gas-liquid stratified flow and the change of the two-phase interface are analyzed in detail.From the view of fluid dynamics,the principle of flow pattern generation is analyzed.The dimensionless parameters of the flow pattern transition characteristic are put forward based on the experimental data,and the Map which can be used to distinguish the flow pattern is drawn.Based on the typical flow patterns of the obtained two-phase flow field,the numerical simulation method for the gas-liquid two-phase flow in the disk system is presented.The VOF model is used to simulate the two-phase fluid flow.The numerical results are compared with the experimental results,and the flow details of gas-liquid distribution,velocity distribution,flow,streamlines and two-phase interface change of the gas-liquid two-phase flow in the disk gap flow field are analyzed in detail.The heat transfer model of gas-liquid two-phase flow is established,and the heat transfer discipline of the system is analyzed under two-phase condition.The variation of local Nusselt number and average Nusselt number and its parametric influence are discussed.The heat transfer characteristics of a rotating disk system with zero disk gap were studied.A coupled heat transfer model was established considering the coupled heat transfer between the solid and the fluid.The numerical simulation model was verified by conducting experiments.The temperature variation of the system is obtained and the distribution of the temperature field in the system is analyzed.The influence of the oil flow rate,the disk rotation speed and the groove number on the system temperature variation is discussed.