Numerical Analysis On LB46 Adjustable Guide Vane Centrifugal Turbine Hydrodynamic Torque Converter

Adjustable hydraulic equipment inherit the excellent transmission quality, such as power to weight ratio, isolation of torsional vibration overload protection,but also has the fuction of continuous adjustable speed to the load machine. Compared to the variable speed torque couplings, adjustable guide vane centrifugal turbine torque converter have a wider applicability in speed adjustment for machines. This paper focus on high seepd ratio centrifugal turbine hydraulic torque converter, to explore a practical numerical simulation method to the inner-flow, and research the theoretical analysis basis for the development of series adjustable guide vane centrifugal turbine torque converter.This paper based on the basic principles of computational fluid dynamics. By combined the structure and working characteristics of centrifugal turbine torque converter, we choose the reasonable turbulence model and frame change model, in order to get a reasonable and practical numerical simulation method. A comprehensive analysis the losses of the inner-flow and the impact on the numerical simulation, and focus on the analysis the impact of the pump and turbine disk friction torque on the torque converter characters, and analysis showed that the numerical results of high speed ratio centrifugal turbine torque converter must introduce the the impact of disk friction torque.The paper gives an example of flow field numerical simulation to the matured domestic application of LB46 torque converter. A detailed analysis of the flow characteristics in different speed ratio is discussed, and the loss of the impeller is calculated in quantitative, calculation error is mainly introduced from the Frame Change/Mixing Model between pump and turbine. By comparing numerical compute characteristic with the experiment characteristic, we analyze the source of error, and from the efficiency point of view for a more reasonable assessment of the calculation error. We calculate the guide vane adjust torque and its variation, this provide the basis for the guide vane adjustment actuators selection. Numerical simulation of further research include the use of unsteady state method of braking situation to research the flow between turbine and pump, and this founded the basis for the reverse conditions forecast. For the weakness of original LB46 hydraulic torque converter pump and fixed guide vane design, the optimization of the fixed guide wheel has about 2% efficiency improvement at the lower speed ratio. Certain operating conditions parameters on the centrifugal turbine hydraulic torque converter transmission performance is also calculated by numerical simulation and analysis methods, including: character changes at different adjustable guide vane position; the way of the pump wheel efficiency change when the pump speed changes; the impact of working fluid viscosity on the performance of torque converter. The results has a certain reference value for the use of adjustable torque converter to implement the practical application of load conditions regulating.