Cavitation Performance Study Based on Numerical Simulation of the Magnetic Driving Pump

Author(s):  
Fanyu Kong ◽  
Xiaokai Shen ◽  
Xufeng Zhang ◽  
Kuanrong Xue ◽  
Shuiqing Zhou ◽  
...  

A new magnetic driving pump with low-NPSHR had been developed to ensure leakage-free for transporting fluid. In hydraulic design, several common measures, according to the equation of cavitation, were applied to lower down the NPSHR of the pump. Moreover, a variable-pitch inducer whose pitch increases gradually was installed at the inlet of impeller. Cavitation performance of the magnetic driving pump and the reasons why the NPSHR was reduced by installing a variable-pitch inducer were analyzed according to the simulation predicted flow field at the pump inlet and inducer. The test of cavitation performance showed that the magnetic driving pump had the excellent cavitation performance, and met the design requirements in flow, head and vibration. The magnetic driving pump presented the reliability after a long period of operation in a petrochemical corporation. Therefore, magnetic driving pumps with low-NPSHR would have a great future in petrochemical, shipping and other important fields.

2014 ◽  
Vol 6 ◽  
pp. 191697
Author(s):  
Xiaoke He ◽  
Jianrui Liu ◽  
Dengpeng Fu

Based on the design theory of liquid-solid two-phase flow centrifugal pump, a new type TLB600-700 desulphurization pump was designed with huge distortions blades design method and impeller inlet super long extension blades design method. Three-dimensional model of internal flow field in TLB600-700 desulphurization pump was built by software PROE5.0, and the three-dimensional unsteady numerical simulation of the internal flow field was calculated, which revealed that the rotor-stator interaction between rotating impeller and volute is the reason why unstable flow generated. Statics analysis was carried out on the impeller in the stationary flow state with the method of fluid-structure interaction, and results indicated that the impeller strength and stiffness meet the design requirements. External characteristic test results of TLB600-700 desulphurization pump showed that all parameters of desulphurization pump designed by innovative method meet design requirements; especially the pump efficiency was increased by 4.15% higher than Chinese national standard.


Author(s):  
Cong Wang ◽  
Yongxue Zhang ◽  
Hucan Hou ◽  
Zhiyi Yuan

Low efficiency and bad cavitation performance restrict the development of the ultra-low specific-speed centrifugal pump (ULSSCP). In this research, combined turbulent boundary layer theory with two-dimension design and two-dimension viscous hydraulic design method has been proposed to redesign a ULSSCP. Through the solution of the displacement thickness in the boundary layer, a less curved blade profile with a larger outlet angle was obtained. Then the hydraulic and cavitation performance of the reference pump and the designed pump were numerically studied. The comparison of performance of the reference pump calculated by the numerical and experimental results revealed a better agreement. Research shows that the average hydraulic efficiency and head of the designed pump improve by 2.9% and 3.3%, respectively. Besides, the designed pump has a better cavitation performance. Finally, through the internal flow analysis with entropy production diagnostic model, a 24.8% drop in head loss occurred in the designed pump.


Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.


2020 ◽  
Vol 1670 ◽  
pp. 012030
Author(s):  
Shiming Chen ◽  
GuichunYang ◽  
Shuang Zhou ◽  
Wenzhuo Chen ◽  
Jinfa Guan ◽  
...  

2020 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Hitoshi Tanaka ◽  
Nguyen Xuan Tinh ◽  
Xiping Yu ◽  
Guangwei Liu

A theoretical and numerical study is carried out to investigate the transformation of the wave boundary layer from non-depth-limited (wave-like boundary layer) to depth-limited one (current-like boundary layer) over a smooth bottom. A long period of wave motion is not sufficient to induce depth-limited properties, although it has simply been assumed in various situations under long waves, such as tsunami and tidal currents. Four criteria are obtained theoretically for recognizing the inception of the depth-limited condition under waves. To validate the theoretical criteria, numerical simulation results using a turbulence model as well as laboratory experiment data are employed. In addition, typical field situations induced by tidal motion and tsunami are discussed to show the usefulness of the proposed criteria.


Sign in / Sign up

Export Citation Format

Share Document