双涡轮液力变矩器的性能改进研究

发布时间：2018-09-17 13:20

【摘要】：双涡轮液力变矩器在工程机械行业应用越来越广泛,作为液力传动系统的核心部件之一,提高液力变矩器的效率是关键。本文结合“浙江临海机械有限公司”委托的科研项目,利用计算流体力学软件,对双涡轮液力变矩器的内部流场及性能进行了数值计算分析,在此基础上分别对泵轮、一级涡轮和二级涡轮进行了多种方案的优化改型,并详细分析改型结果,得出一种最佳优化方案,提高了双涡轮液力变矩器的转矩比和效率。主要研究内容如下:1、根据厂家提供的液力变矩器木模图数据,利用SolidWorks造型软件建立几何模型,并将几何模型导入Bladegen中建立计算流道模型,然后利用CFX计算软件进行数值模拟计算,根据数值模拟计算结果详细的分析了各个转速比工况下泵轮、一级涡轮、二级涡轮和导轮的内部流动情况,并预测得到双涡轮液力变矩器的原始特性,与试验结果对比验证了此方法的正确性;2、针对一级涡轮进出口流动情况,在改变一级涡轮的厚度,数量和进口角度的基础上模拟多种改型方案,找出一级涡轮的最佳改型方案,使得启动工况下的转矩比由3.9提高到4.12,在转速比(0.3~0.703)工况下效率提高了2%~5%。3、根据二级涡轮的进出口流动情况,在调整二级涡轮的进口安放角的基础上计算多种改型方案,从而确定二级涡轮的最佳改型方案,使得效率在转速比(0.3~0.673)工况下比改型前提高了1%~2%;4、通过把一级涡轮和二级涡轮的最优研究方案组合,进行数值模拟计算并对计算结果进行分析得出,启动工况下,转矩比由改进前的3.9提高到4.16,在转速比(0.3~0.703)工况下效率比改型前提高了3%~6%;通过对泵轮的出口的改型,使得泵轮出口的射流/尾流、回流、漩涡等不利流动特征得到了改善,根据数值模拟结果可以得出,启动工况下,转矩比由改进前的3.9提高到4.28,在转速比(0.3~0.646)工况下,效率较改进前提高了4%~6.5%。
[Abstract]:Twin-turbine torque converter is more and more widely used in construction machinery industry. As one of the core components of hydraulic transmission system, improving the efficiency of hydraulic torque converter is the key. Based on the numerical calculation and analysis of the performance of the pump wheel, the first stage turbine and the second stage turbine, a variety of optimization modifications were carried out, and the results of modification were analyzed in detail. An optimal optimization scheme was obtained, which improved the torque ratio and efficiency of the double turbine torque converter. The geometric model of torque converter is established by SolidWorks modeling software. The geometric model is imported into Bladegen to establish the computational runner model. Then the numerical simulation is carried out by CFX software. According to the numerical simulation results, the pump wheel, the first turbine, the second turbine and the guide wheel are analyzed in detail under various speed ratios. The original characteristics of the twin-turbine torque converter are predicted and compared with the experimental results to verify the correctness of the method. 2. According to the inlet and outlet flow of the first-stage turbine, a variety of modification schemes are simulated on the basis of changing the thickness, quantity and inlet angle of the first-stage turbine, and the best modification scheme of the first-stage turbine is found. The torque ratio is increased from 3.9 to 4.12 under start-up condition, and the efficiency is increased by 2%~5% under speed ratio (0.3~0.703). 3. According to the inlet and outlet flow of the secondary turbine, various modification schemes are calculated on the basis of adjusting the inlet and outlet angle of the secondary turbine, so as to determine the best modification scheme of the secondary turbine and make the efficiency at the speed ratio (0.3~0.703). 4. By combining the optimal research scheme of the first stage turbine and the second stage turbine, the numerical simulation and analysis of the calculation results show that the torque ratio increases from 3.9 to 4.16, and the efficiency increases by 3% to 6% under the speed ratio (0.3 to 0.703). Through the modification of the outlet of the pump wheel, the unfavorable flow characteristics such as jet/wake, backflow and vortex at the outlet of the pump wheel are improved. According to the numerical simulation results, the torque ratio is increased from 3.9 to 4.28 under the starting condition, and the efficiency is increased by 4%-6.5% under the rotational speed ratio (0.3-0.646).
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU603

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