NUMERICAL ANALYSIS ON THREE- DIMENSIONAL FLOW FIELD OF TURBINE IN TORQUE CONVERTER

Three-dimensional flow field of turbine in torque converter is simulated by numerical calculation in order to improve the performance of torque converter. Calculation model of a torque converter is presented based on the mixing-plane technology. In the calculation of flow field,the 3D N-S equations are separated by finite-volume method and solved by semi-implicit method for pressure-linked equations(SIMPLE). Based on flow field calculation,the flow field of turbine is simulated. The velocity and pressure in the flow field of turbine are analyzed. The external performance of the torque converter is also calculated. Results of flow simulation show that there are secondary flow,off flow and velocity gradient in turbine passage. The validity of numerical simulation is verified by comparing the results of numerical simulation with experiment data.     

基于三维瞬态流场分析的液力变矩器改型设计

为了提高液力变矩器的外特性,利用UG建立某型液力变矩器叶栅系统全流道模型。借助滑动网格技术,采用Fluent软件对液力变矩器内流场进行三维瞬态数值模拟,并与原结构的试验结果对比,验证了该方法的合理性。在此基础上,根据性能要求对原有变矩器作改型设计,改进了涡轮进口角和出口角等关键参数。结果表明,改型后的液力变矩器具有更加合理的内流场分布和更高的效率,改型设计效果良好。     

公共汽车液力变矩器流场的数值分析

采用Fluent对城市公共汽车液力变矩器的内部流场进行数值分析,并基于分析结果,对不同工况下的工作轮内部流动状况进行流场分析得出其流动规律,为改善流动状况提高传动效率奠定基础。     

工程机械液力变矩器现代设计方法及应用

为适应液力变矩器发展需要,突破传统设计方法的局限性,提高产品研发速率、降低开发成本、提高产品综合性能。在国内率先提出基于三维流动理论的液力变矩器现代设计方法,将计算流体力学CFD技术与激光可视流场分析技术进行无缝结合,突破可视化流场分析、叶片成形及三维瞬态流场计算等关键技术,解决了变矩器内部液体流动不可视、叶形空间复杂曲面成形等难题,创建了包括预设计、叶型设计、性能分析、参数调整、内流场测试、模具设计及样机制造环节等六个环节的设计方法体系。液力变矩器现代设计方法不但保证产品性能的最优化,同时提高了设计到产品的一次成功率,有效缩短了开发时间、降低开发成本,是对传统设计方法的重大突破。     

液力变矩器流动数值模拟的发展与应用

 综述了近几年国内外对于液力变矩器的数值模拟的发展与应用，包括网格划分精细化、模拟方法多样化、流场分析细致化等。重点介绍了瞬态三维尺度解析模拟方法，考虑二次流、气蚀等现象的流场分析，格子Boltzmann方法，考虑温度变化的外特性计算，以及基于Isight的变矩器集成优化等，提出了液力变矩器数值模拟的发展趋势。     

Method of internal 3D flow field numerical simulation for hydrodynamic torque converter

To enhance the performance of a hydrodynamic torque converter and thoroughly understand the trait of inside flow, a numerical simulation method of internal 3D flow for the three-element centrifugal hydrodynamic torque converter was systematically researched and expatiated in this paper. First, the internal flow field of each impeller was calculated. The curves that illustrate the relationships between the pressure differences of the inlet and outlet versus flux were drawn. Second, the concurrent working point of each impeller was approximately estimated. Finally, a calculation was performed considering the influence on each impeller. The flow field of a working point was solved by multiple calculations and the actual working condition was gradually determined. The pressure and velocity distributions of the flow field were proposed. The performance parameters of the hydrodynamic torque converter were predicted. The calculation method, and the proposed pressure and velocity distribution of the flow field, have practical significance for the design and improvement of a hydrodynamic torque converter.     

液力变矩器的叶片设计与研究

液力变矩器具有良好的动力性和经济性,广泛应用于叶片的设计中,是液力变矩器设计的关键,直接影响液力变矩器的性能.叶片设计采用的方法有三种：基形设计、统计设计及基于流场理论设计.前两种都是根据现有的液力变矩器进行改进设计,而基于流场理论的设计对于叶片理论方面的发展具有重要意义.文中基于MATLAB几何方式推导循环圆及流线方程,并据此对叶片进行设计研究.     

Method of internal 3D flow field numerical simulation for hydrodynamic torque converter

To enhance the performance of a hydrodynamic torque converter and thoroughly understand the trait of inside flow, a numerical simulation method of internal 3D flow for the three-element centrifugal hydrodynamic torque converter was systematically researched and expatiated in this paper. First, the internal flow field of each impeller was calculated. The curves that illustrate the relationships between the pressure differences of the inlet and outlet versus flux were drawn. Second, the concurrent working point of each impeller was approximately estimated. Finally, a calculation was performed considering the influence on each impeller. The flow field of a working point was solved by multiple calculations and the actual working condition was gradually determined. The pressure and velocity distributions of the flow field were proposed. The performance parameters of the hydrodynamic torque converter were predicted. The calculation method, and the proposed pressure and velocity distribution of the flow field, have practical significance for the design and improvement of a hydrodynamic torque converter. __________ Translated from Journal of Jilin University (Engineering and Technology Edition), 2006, 36(2): 199–203[译自: 吉林大学学报(工学版)]     

基于内流场分析的液力变矩器改型设计

为了提高液力变矩器的外特性,使其与发动机匹配良好,利用CFD软件对液力变矩器内流场进行三元流场数值计算和分析,在此基础上根据性能要求对原有变矩器作改型设计,改进了叶型进出口角、骨线形状和厚度分布等参数,以期得到分布合理的内流场,从而使改型后的变矩器具有符合要求的更优的外特性。改型后的液力变矩器具有更高的效率和与发动机匹配更优的泵轮容量系数,试验结果与计算结果非常吻合,改型设计效果良好。     

液力变矩器泵轮内流场非定常流动现象研究

液力变矩器内部为复杂的三维非定常湍流流动,为分析变矩器泵轮内部三维非定常流动特性,建立液力变矩器非定常计算流体力学(Computational fluid dynamics,CFD)仿真分析模型,并通过激光多普勒测速(Laser Doppler anemometry,LDA)技术手段对该模型进行验证分析。研究泵轮转速800 r/min,速比为0.6工况下,不同涡轮和导轮位置,对于泵轮内流场非定常流动现象的影响。结果表明:该非定常CFD模型结果与LDA测试结果相吻合,且能够较为准确地反映泵轮内流场非定常流动状态,作为泵轮流场的上游,相对于涡轮对泵轮内部流动的影响,导轮对泵轮内流动状态的影响较大,并主要影响泵轮入口面附近。涡轮主要影响泵轮内流场中间面到出口面的尾流低速区,但影响幅度相对于导轮较小。     

基于Pro／E的液力变矩器叶片设计

液力变矩器是汽车自动变速器的核心部件之一,而液力变矩器设计的关键则是其叶片的设计。对液力变矩器叶片的三维设计方法进行了研究,以Pro/E为设计平台,针对不同型式的叶片采用不同的设计方法,实现了对叶片的三维实体设计。与传统的二维平面设计相比,该设计方法更简便和直观,并可进一步用于叶形优化设计和对叶片曲面进行流体分析;同时,提高了液力变矩器设计的效率,缩短了其研发的时间。     

基于CFD的双涡轮液力变矩器的改进研究

针对YJSW315双涡轮液力变矩器一级、二级涡轮进口流态较差等问题,利用CFD技术对其内部流场及其性能进行了数值计算分析,通过对泵轮叶片出口和一级涡轮数量和厚度的调整,得到了一种优化方案,提高了变矩器性能。改型后的变矩器的起动工况转矩比提高了0.357,两个涡轮都工作时的效率提高2%~4%。提出的研究方法和结论对液力变矩器的改进或研发具有一定的指导意义。     

基于浇铸工艺优化和三维流场分析的液力变矩器改型设计

为提高液力变矩器叶轮的生产质量和生产效率,作者首先对现有的叶轮浇铸方法进行了研究,并提出采用整芯造型法替代原有的拼芯造型,以优化浇铸工艺.由于现有叶轮的弯曲叶片不能满足整芯工艺要求,作者结合三维叶栅设计和三维流场分析对变矩器进行改型设计.变矩器的对比性能试验结果显示,改型后的变矩器性能优良,满足设计要求.     

液力变矩器叶栅系统的三维建模

液力变矩器要求具有良好的动力性和经济性,叶栅系统的设计是液力变矩器设计的关键,直接影响液力变矩器的性能。探讨了液力变矩器叶片三维建模方法,提出了建模方法的基本设计流程。以投影于多圆柱面的等角射影原理为基础,建立了液力变矩器叶栅系统的数学模型。通过求解流线上各分点的坐标,确定叶片在剖分面上的形状,利用直纹面将其连接,从而直接生成叶片形状。这种模型为液力变矩器叶栅系统的设计制造提供了方便,可用于三维流场的数值分析和叶片的快速成型。     

基于细胞沉积的人工骨微管设计及三维流场分析

针对人工骨微管中细胞均匀粘附和营养成分顺利运输所需流速条件,研究支管与主管道之间的夹角对支管中流速的影响以及沿主管道不同位置的支管中液体速度分布,并结合自然骨微观结构以及流体力学中的能量守恒和流量守恒原理,提出一种强化微循环结构并进行三维粘性流场数值分析,将分析结果与单纯仿形结构的流场分析结果比较,结果表明,该结构流速分布更均匀,支管内流速得到很大程度的提高,有利于细胞均匀粘附和进一步提高人工骨设计孔隙率。     

Performance Analysis and Improvement of Flat Torque Converters Using DOE Method

Automotive torque converters have recently been designed with an increasingly narrower profile for the purpose of achieving a smaller axial size and reducing weight. Design of experiment(DOE) and computational fluid dynamics(CFD) techniques are applied to improve the performance of a flat torque converter. Four torque converters with different flatness ratios(0.204, 0.186, 0.172, and 0.158) are designed and simulated first to investigate the effects of flatness ratio on their overall performance, including efficiency, torque ratio, and impeller torque factor. The simulation results show that the overall performance tends to deteriorate as the flatness ratio decreases. Then a parametric study covering six geometric parameters, namely, inlet and outlet angles of impeller, turbine, and stator is carried out. The results demonstrate that the inlet and outlet angles play an important role in determining the performance characteristics of a torque converter. Furthermore, the relative importance of the six design parameters is investigated using DOE method for each response(stall torque ratio and peak efficiency). The turbine outlet angle is found to exert the greatest influence on both responses. After DOE analysis, an optimized design for the flat torque converter geometry is obtained. Compared to the conventional product, the width of the optimized flat torque converter torus is reduced by about 20% while the values of stall torque ratio and peak efficiency are only decreased by 0.4% and 1.7%, respectively.The proposed new optimization strategy based on DOE method together with desirability function approach can be used for performance enhancement in the design process of flat torque converters.     

基于Fluent的某型液力变矩器泵轮流场分析

利用Fluent软件对液力变矩器内流场进行了数值模拟,分析了工作液体在泵轮流道内的流动规律,找出了导致液力变矩器传动效率降低的原因,为下一步优化变矩器结构、改善性能提供了理论基础。     

液力变矩器优化设计研究现状与展望

从设计、流场分析和优化三个方面综述了液力变矩器国内外的研究进展和现状并对未来的发展趋势做了初步的探讨,包括扁平化设计、设计平台的开发以及流场特性细节的研究等。结合上述研究成果,指出设计、流场分析和优化之间的相互关系,重点分析了液力变矩器设计分析集成的发展新趋势,并讨论了集成系统实现的关键技术。     

基于Fluent液力变矩器的外特性数值分析

为了分析液力变矩器的流场特性,对YJ系列某型液力变矩器进行建模和数值模拟。模型采用单叶排单流道的几何模型和多叶排全流道的几何模型,将仿真得出的2组数据和实测力矩数据进行对比,结果表明,应用多叶排全流道的几何模型具有较高的准确性和可靠性。