scholarly journals Numerical and experimental study of variable speed automobile engine cooling water pump

2020 ◽  
Vol 103 (2) ◽  
pp. 003685042092522 ◽  
Author(s):  
Wei Li ◽  
Leilei Ji ◽  
Lingling Ma ◽  
Yongfei Yang ◽  
Ling Zhou ◽  
...  

To investigate the performance of engine cooling water pump in automobile with variable rotating speed, experimental tests and numerical simulation are carried out on an engine cooling water pump under the rotating speed of 2650, 2960, 3700, and 4300 r/min. The hydraulic performance under 3700 r/min rotating speed and the cavitation performance under 340 L/min flow rate are tested and analyzed. The predicted results agree well with the experimental results, indicating that the simulation has high accuracy. The results show that the head of engine cooling water pump increases gradually and the best-effective region moves toward high flow rate condition with the increase in rotating speed. The augment of rotating speed would deteriorate the internal flow fields and causes more energy losses, which is due to the increase in tip leakage flow and enhancement of rotor–stator interaction effects. And, the rotor–stator interaction effect is sensitive to the temperature under various rotating speeds. Furthermore, the required net positive suction head increases with the increase in rotational speed and anti-cavitation performance is weakened during cavitation conditions.

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 278 ◽  
Author(s):  
Wei Li ◽  
Enda Li ◽  
Weidong Shi ◽  
Weiqiang Li ◽  
Xiwei Xu

To analyze the internal flow of the engine cooling water pump (ECWP) under thermodynamic effect, Zwart cavitation model based on the Rayleigh-Plesset equation is corrected, and NACA0015 hydrofoil was selected to verify the corrected model. The cavitation performances of ECWP with different temperatures were numerically simulated based on a corrected cavitation model. Research results show that simulation values of pressure distribution coefficient in hydrofoil surface at 70 °C are in closest agreement with experimental values when the evaporation and condensation coefficients are 10 and 0.002, respectively. With the decrease of absolute pressure in pump inlet, bubbles firstly occurred at the blade inlet side near the suction surface and then gradually extended to the pressure surface, finally clogged the impeller passage. Compared to the inlet section, the cavitation degree is much more serious close to the trailing edge. With the temperature increases, the cavitation in ECWP occurs in advance and rapidly, and the temperature plays an important role in promoting cavitation process in ECWP. Based on the unsteady simulation of ECWP, the influence of cavitation on the performance characteristics is studied. The results provide a theoretical reference for the prediction and optimization of the cavitation performance in ECWP.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Li ◽  
Xiaofan Zhao ◽  
Weiqiang Li ◽  
Weidong Shi ◽  
Leilei Ji ◽  
...  

Changing the blade outlet width is an important method to adjust the performance curves of centrifugal pumps. In this study, three impellers with different blade outlet widths in an engine cooling water pump (ECWP) were numerically simulated based on ANSYS-CFX software. Numerical calculation reliability was validated based on the comparison between simulation results and experimental datum. As the blade outlet width increases, from the performance curves, the investigated ECWP head increases gradually; and the best efficiency point (BEP) offsets to larger flow rate; and the high efficiency region (HER) is becoming larger; and the critical cavitation pressure of the investigated ECWP at BEP increases, which indicates that the cavitation performance at BEP became worse. Compared with the internal flow field, we find vortex appears mainly in the blade passage near the tongue and volute outlet, and the region of the low static pressure is located in the blade inlet suction surface, and impeller inlet and outlet are the regions of high turbulence kinetic energy. Meanwhile, at the same flow rate, with the increase of blade outlet width, the areas of vortex and low static pressure become obvious and bigger.


Author(s):  
We Li ◽  
Pu Wu ◽  
Yongfei Yang ◽  
Weidong Shi ◽  
Weiqiang Li

Cavitation damage in engine cooling water pump is the main factor that shortens the lifespan of the cooling system and gives rise to undesirable phenomena such as vibration and noise. In order to reveal the influence of key factors such as temperature and speed on the cavitation performance of engine cooling water pump, the cavitation performance of the engine cooling water pump under different rotating speeds and temperatures is obtained through the experimental study, and the cavitation flow pattern in the engine cooling water pump under different temperatures is captured using high-speed photography. The result shows that, as the temperature of the working medium changes from 25 °C to 70 °C, the head of the pump increases by 5.9% under the part-loading condition, the efficiency has an increase by 7.1% near the design condition and the shaft power keeps decrease by about 5.6%. Cavitation performance under different rotating speeds is found not to agree with the similar law. With the increase of temperature, the inlet pressure of cavitation initial increases and the cavitation performance deteriorates, the cavitation distribution region inside the impeller gradually expands and presents asymmetric distribution, indicating that thermodynamic effect has a positive effect on the occurrence of cavitation in the engine cooling water pump.


Author(s):  
Wei Li ◽  
Weiqiang Li ◽  
Weidong Shi ◽  
Ling Zhou ◽  
Bing Pei

The engine cooling water pump (ECWP) is an important part in the motor and engine. Using the advanced numerical methods and tools to enhance the ECWP performance, not only could reduce the power consumption and weight, but also can promote the safety and reliability of the vehicle system. The cavitation damage in the ECWP shortens the reliability and life of the motor cooling system, as well as produces vibration and noise. Cavitation in the ECWP has been become an important research topic. To investigate the cavitation performance of ECWP with different impeller diameter, the three dimensional turbulent flow in the ECWP with different impeller diameter was numerically simulated employing the time averaged N-S equation, the standard k-ε turbulent model and multiphase flow model by ANSYS-CFX software. The structured hexahedral mesh has been generated for improving the accuracy of numerical simulation. Comparing with the experimental pump performance results, the cavitation performance is accurately predicted based on structured mesh and cavitation model. The comparison of fluid static pressure and vapor volume fraction contours, hydraulic and cavitation performance was made among different impeller diameter. The cavitation performance curve and bubble distributions under different impeller diameter were compared and analyzed, we find that absolute pressure at the critical cavitation point becomes higher with the decreasing of the impeller diameter, and the anti-cavitation performance becomes worse caused by the increasing of the volume fraction in the impeller. Therefore, there is an optimum impeller diameter value to guarantee the anti-cavitation performance and hydraulic performance of the investigated pump.


2015 ◽  
Vol 812 ◽  
pp. 112-117
Author(s):  
K.M. Kumar ◽  
P. Venkateswaran ◽  
P. Suresh

The coolant (water) pump assumes an important role of cooling system in IC engines. With upgrading of the engine power by turbocharging and turbo inter cooling, the water pump capacity needs to be increased corresponding to the power. This capacity enhancement has to be achieved without calling for a major change in the existing water pump, envelop and related fitment details. This requires a clear understanding of centrifugal pump for its performance parameter. One such engine is upgraded by turbocharging from 195PS to 240PS @2200 rpm. Improving water pump flow by changing the impeller dimensions, impeller casing, increase the suction, delivery pipe diameter had been done. Validation of the water pump in its actual engine installation was taken up as a part of the research work. Flow rate comparison of the new pump with the existing pump was made and the results were analyzed. The new water pump gives better flow rates for the engine speeds up to1800 rpm, beyond which the flow rate is slightly lesser than the existing pump.


2019 ◽  
Vol 21 (5) ◽  
pp. 708-726 ◽  
Author(s):  
Xiaoqin Li ◽  
Xuelin Tang ◽  
Min Zhu ◽  
Xiaoyan Shi

Abstract In the pumping station, the main feedwater system and the reactor system of nuclear power plant, power-supply failure causes strong hydraulic transients. One-dimensional method of characteristics (1D-MOC) is used to calculate the transient process in the pipeline system while three-dimensional (3D) computational fluid dynamics is employed to analyze the turbulent flows inside the pump and to obtain the performance parameters of the pump, and the data exchanges on the boundary conditions of the shared interface between 1D and 3D domains are updated based on the MpCCI platform. Based on the equation of motion of the pump motion parts, the relationship between the external characteristics and the internal flow field in the pump is further investigated because the dynamic behavior of the pump and the detailed fluid field evolutions inside the pump are captured during the transition process, and the transient flow rate, rotating speed, and pressure inside the impeller are comprehensively investigated. Meanwhile, compared with the data gained by experiment and traditional 1D-MOC, the relative errors of rotating speed and the flow rate obtained by 1D-3D coupling method are smaller than those by 1D-MOC. Furthermore, the influences of the main coupling parameters and coupling modes on the calculation results are analyzed, and the cause of the deviation is further explained.


2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Kenji Shingai ◽  
Nobuaki Okamoto ◽  
Yuta Tamura ◽  
Kiyohito Tani

A series of numerical simulations for a Francis turbine were carried out to estimate the unsteady motion of the cavity in the draft tube of the turbine under a much larger flow rate condition than the swirl-free flow rate. The evaporation and condensation process was described by using a simplified Rayleigh–Plesset equation. A two-phase homogeneous model was adopted to calculate the mixture of gas and liquid phases. Instantaneous pressure monitored at a point on the draft tube formed long-period pulsations. Detailed analysis of the simulation results clarified the occurrence of a uniquely shaped cavity and the corresponding flow pattern in every period of the pressure pulsations. The existence of a uniquely shaped cavity was verified with an experimental approach. A simulation without rotor-stator interaction also obtained long-period pulsations after an extremely long computational time. This result shows that the rotor-stator interaction does not contribute to the excitation of long-period pulsations.


2017 ◽  
Vol 31 (5) ◽  
pp. 2319-2329 ◽  
Author(s):  
Li Wei ◽  
Chuan Wang ◽  
Weidong Shi ◽  
Xiaofan Zhao ◽  
Yongfei Yang ◽  
...  

Author(s):  
Takaki Igoshi ◽  
Yuki Uchinono ◽  
Emosi Koroitamana ◽  
Koichi Ishizaka ◽  
Satoshi Watanabe ◽  
...  

The installation of inducer upstream of main impeller is an effective method to improve the suction performance of turbopump. However, various types of cavitation instabilities are known to occur even at the designed flow rate as well as in the partial flow rate range. In the present study, we focus on the leading edge sweep of inducer and investigate its effect on the suction performance as well as on the onset of cavitation surge phenomenon. Flow measurements including casing wall pressure measurements, high-speed video observations, and limiting streamline observations are carried out, and discussions will be made based on those results about the influence of backward leading edge sweep on the internal flow of the inducer as well as its relation to the cavitation performance.


Author(s):  
Baoling Cui ◽  
Mingzhe Cai ◽  
Yifan Li

This study is to reveal the influence of incoming flow containing air on the internal flow and performance of a high-speed inducer. Numerical calculations were performed herein under different air volume fraction conditions based on the shear-stress transport turbulence model and the Eulerian–Eulerian heterogeneous flow model. The external characteristic, cavitation performance and visualization experiment were conducted under the air–water two-phase condition. As a result, the effect of incoming flow containing air under small flow rate condition on the decline of the inducer head was larger than that under large flow rate condition. The proper air volume fraction was beneficial to the improvement of the inducer cavitation performance. As the air volume fraction increased, the pressure gradients in the axial and radial directions of the inducer gradually reduced and the supercharging performance of the inducer also worsened. The flow near the hub in the flow channel became messy, and the turbulence energy increased. The air mainly concentrated in the leading edge rim and the low blade height region near the hub in the flow channel. The air expanded in the circumferential, radial and axial direction as the air volume fraction increased.


Sign in / Sign up

Export Citation Format

Share Document