Numerrical Simulation And The Study Of Stator's Flow Line Torus Helix Of Torque Converter

Hydraulic torque converter is the device which uses liquid kinetic energy for energy conversion and transmission,widely used in ships and vehicles on the main drive.Hydraulic torque converter has many advantages,such as automatic adaptability,overload protection,improve vehicle comfort,extend the life of transmission parts.However,a significant drawback of the torque converter is that the efficiency is not high enough to affect the fuel economy of the vehicle.Every day millions of torque converters are running,as long as the efficiency is improved,the total amount of fuel savings and the total amount of emissions will be a very impressive figure.Therefore,to study the design method of hydraulic torque converter,to improve the efficiency of hydraulic torque converter,for energy-saving emission reduction is of great significance.The torque converter is mainly composed of a pump wheel,a turbine and a stator.In these three wheels,the improvement of the stator is the cheapest.Therefore,it is feasible to study the design method of the stator in order to improve the performance of the torque converter.In this paper,the actual method of the torque converter is studied.Considering that the linearity of the three-dimensional flow field is the most basic factor affecting the efficiency of the torque converter,the three-dimensional circular arc and the straight line are most suitable for use as a three-dimensional streamline,However,since the deflection angle between the inlet and the outlet of the stator is very large and the flow distance inside the stator is very short,it is not feasible to use arc and straight line segment to replace the three-dimensional flow line for studying by mathematical verification.In addition to the straight line and the arc,the helix has a constant or approximately constant curvature.In this paper,a new design method of statorgeneralized torus helix design method,was proposed.The generalized torus helix equation of stator was established.The equation reflecting the interrelationship among polar angle,blade angle and offset angle was derived.How to assess a design scheme of flow field was studied.The scheme selecting mechanism of flow field design reasonability was put forward.A parameterized design program code was developed.All equations were verified.In order to improve the modeling accuracy,in this paper,a high-precision modeling method which uses a four-segment circular arc and a straight line segment are used to approximate the inner and outer ring axial flow line-automatic segmented multi-segment arc approximation method was studied.A parametric program code was developed by using objectoriented design.The program code can perform whole calculation,output an Auto Lisp program used to generate a revolution solid of the stator model,output the stator's pressure surface and the suction surface point cloud coordinates,and output data used for post-process programming of flow field simulation.To complete the modeling of the guide wheel,running AutoLisp program in AutoCAD,automatically generate the guide wheel rotation solid model,and cut it by the cutting surface which is generated by importing the stator's pressure surface and the suction surface point cloud coordinates into UG.Finally the flow path model of the stator is obtained.The Gambit software is used to mesh the stator duct model and then the grids are inputted to the software Fluent to be simulated numerically.After setting all parameters,iterative computation is performed.According to the numerical calculation results of the stator,the flow field of the stator is analyzed.The velocity flow field and pressure flow field in the flow field of the stator are mainly analyzed,and the bad phenomena(high/low velocity flow area,high/ low pressure area,countercurrent area,etc.)exist in the flow field of the stator are analyzed.And compared with the literature.The results show that the generalized helical helix design method can improve the parameter distribution of the flow field and improve the performance of the torque converter.