Numerical Simulation And Performance Prediction Of Car Pumps

With the continuous development of science and technology,automotive water pump, as the important part of the automotive coolingsystem, its reliability and suitability has attached more and more attentionfrom designers, manufacturers and users. The widespread development ofmodern cars, as well as the universal application of the internal combustionengine technology, all promotes the development of automotive waterpumps. However, people are not comprehensive understand the complexflow law of pumps, so the pump design is still in a semi-empirical,semi-theoretical development period. Usually the development of pumpproduct subject to the test and then to improved process from design totrial, it takes a lot of time as well as human and material resources. Aftercompleting the design of pump, if we can accurately predict the pumpperformance, it would greatly simplify the design process of the pump,thereby reducing the time and saving the resources.At present, there are some relevant researches about the performanceprediction of centrifugal pumps at home and abroad. However, theautomotive water pumps, as its small size, high speed, wide operatingconditions, lower efficiency and larger the number of revolutions, it flowsmore complex, and the performance is more difficult to predict, so it isnecessary for us to study and explore the performance prediction ofautomobile water pump in-depth..In this paper, the specific research content and results are as follows:(1)On the basis of reading a large number of documents, weunderstand the centrifugal pump hydraulic design and CAD Research athome and abroad, and summarize the research progress and future trends of the centrifugal pump performance prediction at home and abroad,introduce three performance prediction method including hydraulic losses,flow field analysis and neural network method. By analyzing andcomparing, we select hydraulic losses method to predict the performanceof automotive water pumps.(2)The impeller is the core component of the centrifugal pump, whilecentrifugal pump impeller shaft surface channel design is the key point ofimpeller design. Combing with the existing outstanding centrifugal pumphydraulic model, and basing on the function of the average ratio of thenumber of revolutions and the point of the flow channel online, fit thechannel midline space using free curves. Then basing on the given F-Lcurve, we get the derivation of the equation of the flow line of the frontand back cover, in order to achieve CAD drawing process of a centrifugalpump impeller shaft plane projection.(3)Based on a two-dimensional map of the enterprise automotivewater pump, we establish three-dimensional models and do fullthree-dimensional viscous numerical simulation of the pumps. Comparethe numerical results with the experimental values, and verify thereliability of the numerical results and get the performance parameters ofthe pump. Then do the theoretical analysis of the hydraulic loss of thevarious components of the pump, establish the hydraulic loss model ofeach pump components, through the regression analysis establish the losscoefficient and Reynolds number in the various components loss model aswell as the specific speed relationship combined with numericalcalculation. And it also puts forward reasonable proposals to reducehydraulic losses of each part of automobile water pump.(4)Do numerical simulation of automotive water pumps at differentspeeds and get the performance curves at different speeds, then analyze thedistribution of the flow field at different speed, raise appropriate guidancefor the speed control when the car starts. Finally, do numerical calculation for the impeller alone and compare the calculation results with the wholeflow passage conditions.