基于CFD的叶片参数对液力变矩器的性能影响分析

发布时间：2018-05-13 22:19

本文选题：液力变矩器 + 叶片数　；参考：《长安大学》2017年硕士论文

【摘要】：液力变矩器作为液力传动的重要元件之一,在自动变速器中得到了广泛应用。在对液力变矩器进行设计时,最核心的部分就是叶栅系统,其设计的好坏直接影响着液力变矩器的使用性能。叶栅系统参数主要包括叶片进口角、出口角、叶片数以及循环圆等参数。本文以某型号液力变矩器为研究对象,以CFD为载体,研究分析了叶片数和叶片进、出口角度对液力变矩器性能的影响。首先分析了液力变矩器三个工作轮的工作特性,根据能量平衡建立了液力变矩器的数学模型,并对其静态特性进行了分析。借助三坐标激光扫描仪得到了液力变矩器的各工作轮的整体点云和流道点云数据,通过Imageware的后处理和UG的三维造型得到了液力变矩器的三维实体模型。将简化后的流道模型导入ICEM进行网格划分,并运用CFD软件FLUENT进行三维流场数值模拟。在高速比工况下,对不同工作轮(泵轮、涡轮、导轮)叶片数的液力变矩器进行三维流场数值模拟,得到了各工作轮进出口面的速度和压力变化并分析了原因,同时根据三维流场的计算结果分析了不同工作轮叶片数对液力变矩器特性的影响。对各个工作轮叶片数进行了合理组合并选取四种典型方案进行分析研究,并将计算结果与实验对比,验证了三维流场计算结果的准确性。将不同叶片数组合的变矩器性能进行对比分析,得到了不同叶片数组合对液力变矩器性能的影响。根据液力变矩器的数学模型,研究了不同转速比时叶片角度对变矩器性能参数的影响。高速比工况下通过三维流场数值模拟,得到了不同进、出口角度时各工作轮进、出口面的速度和压力分布的差异并阐明了原因。鉴于导轮和泵轮出口角对变矩器性能影响较大,根据三维流场计算结果对泵轮和导轮不同出口角时变矩器的特性进行了对比分析,得到了出口角的变化对变矩器性能的影响。
[Abstract]:As one of the important components of hydraulic transmission, hydraulic torque converter has been widely used in automatic transmission. In the design of hydraulic torque converter, the most important part is cascade system, whose design directly affects the performance of hydraulic torque converter. The parameters of cascade system mainly include blade inlet angle, outlet angle, blade number and cycle circle. In this paper, the influence of blade number, blade inlet and outlet angle on the performance of hydraulic torque converter is studied with a certain type of hydraulic torque converter as the research object and CFD as the carrier. Firstly, the working characteristics of three working wheels of hydraulic torque converter are analyzed. According to the energy balance, the mathematical model of hydraulic torque converter is established, and its static characteristics are analyzed. The data of the whole point cloud and the flow path point cloud of each working wheel of the torque converter are obtained by means of the 3D laser scanner. The 3D solid model of the hydraulic torque converter is obtained by the post-processing of Imageware and the 3D modeling of UG. The simplified flow channel model is imported into ICEM to mesh and the 3D flow field is simulated by CFD software FLUENT. Under the condition of high speed ratio, the flow field of hydraulic torque converter with different blades of pump wheel, turbine and guide wheel is numerically simulated, and the velocity and pressure changes of the inlet and outlet surfaces of each working wheel are obtained and the reasons are analyzed. At the same time, the influence of the number of blades on the characteristics of hydraulic torque converter is analyzed according to the results of three-dimensional flow field. The number of blades of each working wheel is reasonably combined and four typical schemes are selected for analysis and study. The results of calculation are compared with those of experiments to verify the accuracy of the results of three-dimensional flow field calculation. The performance of torque converter with different blade number combinations is compared and analyzed, and the effect of different blade number combinations on the performance of hydraulic torque converter is obtained. According to the mathematical model of hydraulic torque converter, the influence of blade angle on the performance parameters of torque converter with different rotational speed ratio is studied. The difference of velocity and pressure distribution at different inlet and outlet angles is obtained by numerical simulation of three dimensional flow field under high speed ratio. In view of the great influence of the outlet angle of the guide wheel and the pump wheel on the performance of the torque converter, the characteristics of the time-varying moment converter at different outlet angles of the pump wheel and the guide wheel are compared and analyzed according to the results of three-dimensional flow field calculation, and the influence of the change of the outlet angle on the performance of the converter is obtained.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH137.332

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