scholarly journals Numerical Simulation of Cavitation Performance in Engine Cooling Water Pump Based on a Corrected Cavitation Model

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 278 ◽  
Author(s):  
Wei Li ◽  
Enda Li ◽  
Weidong Shi ◽  
Weiqiang Li ◽  
Xiwei Xu
Keyword(s):  
Cooling Water ◽  
Internal Flow ◽  
Absolute Pressure ◽  
Inlet Section ◽  
Water Pump ◽  
Cavitation Model ◽  
Suction Surface ◽  
Pressure Surface ◽  
Engine Cooling ◽  
Cavitation Performance

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.

scholarly journals Numerical Prediction and Performance Experiment in an Engine Cooling Water Pump with Different Blade Outlet Widths

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Li ◽  
Xiaofan Zhao ◽  
Weiqiang Li ◽  
Weidong Shi ◽  
Leilei Ji ◽  
...  
Keyword(s):  
Flow Rate ◽  
High Efficiency ◽  
Static Pressure ◽  
Cooling Water ◽  
Internal Flow ◽  
Water Pump ◽  
Centrifugal Pumps ◽  
Suction Surface ◽  
Engine Cooling ◽  
Performance Curves

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.

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 ◽  
...  
Keyword(s):  
Flow Rate ◽  
Cooling Water ◽  
Internal Flow ◽  
Water Pump ◽  
Tip Leakage Flow ◽  
Rate Condition ◽  
Rotating Speed ◽  
Engine Cooling ◽  
Cavitation Performance ◽  
Rotor Stator Interaction

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.

Influence of Different Impeller Diameter on Cavitation Performance in an Engine Cooling Water Pump

2015 ◽  
Author(s):  
Wei Li ◽  
Weiqiang Li ◽  
Weidong Shi ◽  
Ling Zhou ◽  
Bing Pei
Keyword(s):  
Volume Fraction ◽  
Cooling System ◽  
Three Dimensional ◽  
Cooling Water ◽  
Absolute Pressure ◽  
Water Pump ◽  
Hexahedral Mesh ◽  
Engine Cooling ◽  
Cavitation Performance ◽  
Critical Cavitation

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.

Investigation of the cavitation performance in an engine cooling water pump at different temperature

2020 ◽  
pp. 095765092098464
Author(s):  
We Li ◽  
Pu Wu ◽  
Yongfei Yang ◽  
Weidong Shi ◽  
Weiqiang Li
Keyword(s):  
High Speed ◽  
Cooling System ◽  
Cooling Water ◽  
High Speed Photography ◽  
Asymmetric Distribution ◽  
Water Pump ◽  
Engine Cooling ◽  
Cavitation Performance ◽  
Working Medium ◽  
Different Temperatures

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.

Numerical calculation and optimization designs in engine cooling water pump

2017 ◽  
Vol 31 (5) ◽  
pp. 2319-2329 ◽  
Author(s):  
Li Wei ◽  
Chuan Wang ◽  
Weidong Shi ◽  
Xiaofan Zhao ◽  
Yongfei Yang ◽  
...  
Keyword(s):  
Numerical Calculation ◽  
Cooling Water ◽  
Water Pump ◽  
Engine Cooling

Investigation of Internal Flow and Characteristic Instability of a Mixed Flow Pump

2009 ◽  
Author(s):  
Masahiro Miyabe ◽  
Akinori Furukawa ◽  
Hideaki Maeda ◽  
Isamu Umeki
Keyword(s):  
Flow Rate ◽  
Internal Flow ◽  
Rotating Stall ◽  
Leakage Flow ◽  
Suction Surface ◽  
Mixed Flow ◽  
Vaned Diffuser ◽  
Flow Angle ◽  
Pressure Surface ◽  
Flow Pump

The relationship between pump characteristic instabilities and internal flow was investigated in a mixed flow pump with specific speed of 700 (min−1 m3/min, m) or 1.72 (non-dimensional) by using a commercial CFD code and a dynamic PIV (DPIV) measurement. This pump has two positive slopes of a head-flow characteristic at the flow rates of about 60%Qopt and 82%Qopt. In the authors’ previous study, it was clarified that the characteristic instability at 82%Qopt is caused by the diffuser rotating stall (DRS) and the backflow near the hub of the vaned diffuser plays an important role on the onset of the diffuser rotating stall. In the present paper, the investigation is focused on the instability at about 60% Qopt. Based on both of experimental and numerical results, it was clarified that the characteristic instability at 60%Qopt is caused by the backflow at the inlet of the impeller tip and the leakage flow from the impeller pressure surface to the suction surface plays an important role on the onset of the backflow. The behaviors of backflow at the impeller inlet were visualized by the DPIV measurements and CFD simulation. Moreover, internal flow was investigated in detail and the occurrence of characteristic instability is assumed as follows: At the partial flow rate, the flow angle at the inlet of the impeller tip decreases and the flow hits the impeller pressure surface. Then, the blade loading at the inlet of impeller tip is increased and the recirculation at the leading edge and the leakage flow rate from pressure surface to suction surface increases. The leakage flow causes to generate vortices at the inlet of the suction surface of the impeller. As the flow rate is further decreased, the vortices develop to backflow with swirl. The leakage flow has peripheral component of absolute velocity and the swirling energy is continuously supplied by the backflow. Therefore, even the passage flow at the inlet of the impeller has been getting pre-swirling. The theoretical head, the Euler head is decreased due to the pre-swirling. Moreover, based on the CFD results, the pre-swirling and unsteady vortices near the suction surface of the impeller causes pump characteristic instability. When the flow rate is decreased further more, total head rises because the flow pattern in the impeller changes to centrifugal type due to the backflow from the vaned diffuser at the hub region.

scholarly journals Hydraulic performance prediction and optimization of an engine cooling water pump using computational fluid dynamic analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253309
Author(s):  
Libin Tan ◽  
Yuejin Yuan ◽  
Man Zhang
Keyword(s):  
Computational Fluid Dynamic ◽  
Performance Prediction ◽  
Fluid Dynamic ◽  
Cooling Water ◽  
Hydraulic Performance ◽  
Pump Efficiency ◽  
Optimized Design ◽  
Water Pump ◽  
Engine Cooling ◽  
Pump Head

In current research, the hydraulic performance prediction and optimization of an engine cooling water pump was conducted by computational fluid dynamic (CFD) analysis. Through CFD simulation, the pump head, shaft power and efficiency for the original pump at volume flow rate 25 L/min and impeller rotating speed 4231 r/min were 3.87 m, 66.7 W and 23.09% respectively. For improving hydraulic performance, an optimization study was carried out. After optimization, four potential optimized designs were put forward. The efficiency of the optimized design No.1 for engine cooling water pump was nearly 6% higher than that of the original pump model; and the head of the optimized design No.2 for engine cooling water pump was 9% higher than that of the original pump model. Under the condition of maintaining the pump head and considering comprehensive improvement effect, the optimized design No.3 was considered as the best design and selected as the test case for validating the optimum design. The hydraulic performance predictions for this optimum engine cooling water pump agreed well with experimental data at design condition with relative discrepancies of 2.9% and 5.5% for the pump head and pump efficiency, respectively. It proved that performance prediction calculation model and the automatic optimization model were effective. This research work can provide theoretical basis for the design, development and optimization of engine cooling water pump.

The Effect of Hub Inlet Boundary Layer Skewing on the Endwall Shear Flow in an Annular Turbine Cascade

1979 ◽  
Author(s):  
J. P. Bindon
Keyword(s):  
Boundary Layer ◽  
Leading Edge ◽  
High Energy ◽  
Surface Flow ◽  
Inlet Section ◽  
Turbine Cascade ◽  
Suction Surface ◽  
Pressure Surface ◽  
Displacement Thickness ◽  
Real Machine

The inner annulus endwall boundary layer between the blades was examined experimentally in an annular turbine cascade for conditions of inlet boundary layer skewing similar to that in a real machine and for the collateral inlet as in all cascade tests. Skewing was introduced by rotating the hub ahead of the cascade. The slot created ahead of the cascade by the rotating hub caused major changes in the endwall surface flow visualization patterns seen as compared to an uninterrupted inlet section. Skewing did not alter the basic pattern except to increase the surface crossflow angles. Traverses taken at 15 points between the blades showed a sharp thickening followed by sharp thinning of the boundary layer near the pressure surface leading edge. The overall distribution of displacement thickness was not greatly influenced by skewing and generally showed a thicker layer near the suction surface and an extremely thin layer near the pressure surface at exit. Skewing increased significantly the amount of fluid involved in crossflow. While surface crossflow angles were everywhere greater with increasing inlet skewing, the increases were more marked in the mid to upper reaches of the shear layer. Loss profiles near the inlet showed the presence of high energy fluid near the surface but near the exit skewed and collateral profiles were more similar.

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