Matching And Optimization Of W375 Torque Converter

With the development of the automobile industry, due to their own excellence hydraulic transmission technology has been widely applied in cars and construction machinery industry at home and abroad. At present, the hydraulic transmission of the internal combustion engine vehicles using the working conditions are far from their best work in the region, failed to realize the engine and hydraulic transmission systems of the best matching. Therefore, by optimizing the matching engine and hydraulic drive system to improve transport efficiency vehicles, lower fuel consumption and reduce exhaust pollution has a greater potential, Either from the social, economic or to raise the overall level of hydraulic transmission vehicles,it is a very important and significance research topic. Papers for heavy-duty off-road vehicles used by TC AMT system, torque converter type of W375, in its flow field numerical simulation and analysis of the common post-match, on the basis,using the optimization software Sculptor preliminary study the optimization method in flow field characteristics, thereby improving the design.The main contents of papers:(1) Set out the background and significance of topics,to improve the matching of engine and torque converter has a certain theoretical significance and practical value, introduce the principle of torque converter.(2) Establish the principles and objectives of the W375 torque converter that is applied in off-road vehicle,According to experimental data,gained the characteristic curve of Torque converter and engine,Engine and torque converter in common with the curve matching,the work of the two common points, failed to pass the highest starting torque point and the most economical fuel consumption point.To achieve the matching can be achieved through the use of different effective diameter D and the pump wheel torque coefficientλB of converter torque.Figure 2.3 is the input characteristic curve of W375 torque converter,As can be seen from the curve,the torque converter is through wear and,So as long as the figure counter-clockwise rotation of the fan-shaped region can be achieved on the purpose of improving the match.(3) Introduced the theory of CFD, to lay a theoretical foundation for the application of Fluent calculated,so the fluent can be deeper awareness and understanding of.Gives the flow field calculation steps,Corresponding to each step are given in fluent software settings,Including the choice of simulation models, algorithms, discrete format,and Set of boundary conditions.Analysis of the Flow Field is applied to Mixing plane model,introduced Mixing plane theory ,and the corresponding set.oil in the torque converter work in very complex flow,Therefore, the internal flow analysis of torque converter to do the basic assumptions.(4) Flow field based on the results of numerical analysis of the pump wheel and turbine rotation and guide the flow field Road, the following conclusions:1) Impact on the efficiency of pump of the main factors is the second flow and off flow. Between face and non-face caused by the velocity gradient is the main reason for the second mobile. imports-flow Impact on non-surface, In the vicinity of the entrance of non-face to focus a high-speed flow of oil, the speed of face near is the relatively low. Due to the existence of velocity gradient along the outer ring to enable the working oil flows from non-face face,Face of the original slow oil was forced to flow along the inner ring to non-face,To form the secondary flow.Secondary flows will have its own energy consumption of fluid,This is because the fluid particles bump into each other, friction generates heat and consumes .The emergence of flow block the flow of sap flow,add increase of the flow loss,Pump is also affecting the efficiency of round one of the main reasons.2) Comprehensive analysis of the characteristics of turbine flow,Impact on the efficiency of the turbine main factors: leaves emerging from the larger Bending in the local stream,the second movement of The central flow channel and the velocity gradient within the larger flow channel.Secondary flow and velocity gradient would give rise to oil relative motion between particle,Inter-particle friction heat, consumed energy of the work of oil.In addition, the off-flow effect of impeding the flow, is also one of the main factors affected turbine efficiency.3)the main factors of impacting on the guide efficiency is Service flow face of shocks and Department of non-face large-scale counter-current.Countercurrent flow and positive impact,Trigger a new impact,Flow from there.Therefore, the impact of loss of the guide pulley of the energy loss is dominant.(5) based on the calculation results of Fluent flow field,Optimization of the application for sculptor.This article import the cas files in fluent,to establishment the deformation domain,the establishment of deformation domain can affect the quality of optimization results and to optimize the quality of.by the establishment four Bound group,Group to coordinate moving variables, import and export of the speed difference of the objective function to optimize.Carried out before and after the leaf of comparison and numerical comparison,Leaf shape was found to have taken place in the definition of the movement distance of the deformation,After optimization ,the velocity difference of import and export,is larger. The optimized files cas is calculated in fluent,gained optimization matching the common curve of the torque converter and engine,Match the results of a new,the fan-shaped region of Torque converter counter-clockwise movement, starting torque is large, maximum efficiency point of torque converter bias for maximum efficiency point of engine,improve the matching results.(6) As the summary of the paper, the sixth part expounded all the work and research results and make prospective to future work.