Numerical calculation and optimization designs in engine cooling water pump

다국어 초록 (Multilingual Abstract)

The cavitation damage in the Engine cooling water pump (ECWP) is the key factor that shortens the lifespan of automobile cooling systems, and causes vibration and noise. To improve cavitation performance and external characteristics of ECWP, three optimized models were designed on the basis of WP7 diesel ECWP. The whole flow fields in three models and the prototype pump were numerically simulated, employing the time averaged Navier-Stokes equation, the standard k-ε turbulent model and Zwart-Gerber-Belamri multiphase flow model by ANSYS-CFX software. Pressure distribution, turbulent kinetic energy distribution, bubble volume fraction distribution, external characteristics and cavitation performance of the prototype pump and optimized models were compared and analyzed. The results show that the external characteristics and cavitation performance of the optimized models are significantly better than that in the prototype pump. Through decreasing the inlet blade angle and wrap angle, extending the blade to inlets and extending a certain inclination in the blade, shock loss in blade inlet was reduced and so, the performance of pump will be improved. The flow condition at blade inlet will also be improved greatly, which in turn improves cavitation performance. When reducing the quantity of blades, the excretion coefficient will drop, flow area of blade inlet becomes bigger, but head has a little drop. And the pump optimized by reducing the quantity of blades has the optimal cavitation performance among three optimized models. With the decrease of impeller diameter, the absolute pressure in the critical cavitation point becomes bigger, the inlet bubble volume fraction at the same absolute pressure increases while cavitation performance gets worse. The obtained numerical results were compared with the experimental ones, and the outcome showed the same tendency between the two along with acceptable error.

참고문헌 (Reference)

1 L. Hua, "The study of characteristics prediction of car pumps based on hydraulic loss model" Shanghai Jiao Tong University 2012

2 "T81266.2, Internal combustion ECWPs, Part 2: Asemblies and test method" China Machine Press 2010

3 R. Cipollone, "Sliding vane rotary pump in engine cooling system for automotive sector" 76 : 157-166, 2015

4 S. Xiang, "Research of cooling system of automobile engine based on AMESim" Chang’an University 2014

5 Y. Z. Chen, "Pump Handbook" China Petrochemical Press 2003

6 Y. Yang, "Optimum design of automobile water pump based on CFD" 32 (32): 477-481, 2014

7 J. F. Zhang, "Numerical simulation of recirculation control at centrifugal pump inlet" 33 (33): 402-407, 2012

8 L. Jing, "Numerical simulation and performance prediction of car pumps" Shanghai Jiao Tong University 2013

9 Tang Xue-lin, "Numerical investigations on cavitating flows with thermodynamic effects in a diffuser-type centrifugal pump" 대한기계학회 27 (27): 1655-1664, 2013

10 XiaoMei Guo, "Numerical and experimental investigations on the cavitation characteristics of a high-speed centrifugal pump with a splitter-blade inducer" 대한기계학회 29 (29): 259-267, 2015

11 H. Song, "Fundamental research on intelligent cooling system for vehicle engines" Zhejiang University 2012

12 S. Duplaa, "Experimental study of a cavitating centrifugal pump during fast startups" 132 (132): 365-368, 2012

13 N. J. Liao, "Discussion on the pump cavitation in LJ465Q series engine" 2 : 177-183, 2010

14 D. H. Sheng, "Design and test research on electronic pump cooling system of engine" 40 (40): 5-9, 2012

15 Xianwu Luo, "Comparison of cavitation prediction for a centrifugal pump with or without volute casing" 대한기계학회 27 (27): 1643-1648, 2013

16 W. Li, "Cavitation performance prediction of engine cooling water pump based on CFD" 30 (30): 176-180, 2012

17 G. L. Chahine, "Cavitation and cavitation erosion" 2014

18 Y. Bo, "Auto Water pump structural development and heat dissipation effect research based on Pump Linx" 1 : 40-42, 2016

19 Houlin Liu, "Assessment of a turbulence model for numerical predictions of sheet-cavitating flows in centrifugal pumps" 대한기계학회 27 (27): 2743-2750, 2013

20 F. Salvatore, "An improved boundary element analysis of cavitating three-dimensional hydrofoils" 2001