Research On Cascade Design And Performance Prediction Of Hydraulic Torque-Retarder Assembly

The cascades system design method for Hydraulic Torque-Retarder Assembly(HTRA)is presented based on CFD.HTRA brake impeller cascade parametric design model,traction and braking characteristics prediction models based on three-dimensional flow are established.It obtains the combination of parametric design,characteristics prediction and optimization algorithms.HTRA integrated optimization platform is built and the brake impeller design parameter sensitivity is studied.Finally brake impeller cascades of HTRA are optimized and the prototype is manufactured with experimentally verified.Current converter cascade system characteristics are analyzed,and HTRA cascades parametric design model is established.The method to establish the brake impeller model by cascades geometric parameters(axial width,inlet and outlet angle of blade etc.),which can generate serialized HTRA.Considering the brake impeller idling problem of HTRA in traction condition,HTRA steady traction characteristics predictive models are established based on three-dimensional flow theory.The variation of brake impeller torque with drive impeller speed in traction condition is studied,and the brake impeller idling speed prediction model based on CFD simulation is established.Combined with experimental design,the impact of impeller speed and design parameters to HTRA traction brake idling speed is studied,and the key parameters affecting brake impeller idling speed are found.Besides,the influence and interactive effects of parameters are analyzed,which provides mathematical models for HTRA brake impeller idling speed setting in steady traction condition.In addition,to solve the idling problem of stator impeller in braking condition of HTRA,the prediction model showed braking characteristics is established based on three-dimensional flow theory.The idling speed of stator impeller is calculationed by factorial design method,the braking characteristic is predicted and the sensitivity Analysis of design parameters of brake impellers on braking condition are studied.Finally,by comparing the different effects of design parameters to HTRA traction characteristic and braking characteristic,HTRA brake impeller cascades multi-objective optimization model is established.Combining HTRA traction characteristic prediction model and braking characteristic prediction model,a HTRA optimization design system is established with integrated cascade modeling,meshing,CFD simulation and intelligent optimization.HTRA based on hydraulic converter with diameter 375 mm is designed and optimized,and the prototype is produced with experimentally verified.The results show that,the established HTRA design system could optimize braking performance ensuring the traction performance requirements.