2432 Internal Flow Analysis of Low Specific Speed Centrifugal Pump with Circular Casing

2006 ◽  
Vol 2006.2 (0) ◽  
pp. 183-184
Author(s):  
Jun MATSUI ◽  
Junichi KUROKAWA ◽  
Kouichi NISHINO ◽  
Young-Do Choi ◽  
Kouichi MOURI
Keyword(s):  
Centrifugal Pump ◽  
Flow Analysis ◽  
Internal Flow ◽  
Low Specific Speed ◽  
Specific Speed

scholarly journals Optimal Design of Slit Impeller for Low Specific Speed Centrifugal Pump Based on Orthogonal Test

2021 ◽  
Vol 9 (2) ◽  
pp. 121
Author(s):  
Yang Yang ◽  
Ling Zhou ◽  
Hongtao Zhou ◽  
Wanning Lv ◽  
Jian Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Large Scale ◽  
Internal Flow ◽  
Orthogonal Test ◽  
Centrifugal Pumps ◽  
Initial Model ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Four Levels

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.

Analysis on Effects of the Blade Wrap Angle and Outlet Angle on the Performance of the Low-Specific Speed Centrifugal Pump

2011 ◽  
Vol 354-355 ◽  
pp. 615-620 ◽  
Author(s):  
Wei Li ◽  
Wei Dong Shi ◽  
Ting Jiang ◽  
Yan Xu ◽  
Tong Tong Li
Keyword(s):  
Centrifugal Pump ◽  
Stokes Equations ◽  
Internal Flow ◽  
Navier Stokes ◽  
Outlet Angle ◽  
Study Results ◽  
Wrap Angle ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Blade Wrap Angle

In order to research the effect of the blade wrap angle and outlet angle on the hydraulic performance of the low-specific speed sewage pump, the Reynolds time-averaged Navier-Stokes equations was discretized based on the finite volume method, and the modified k-ε turbulence model were chosen in FLUENT. Numerical simulation of the internal flow within the centrifugal pump with the specific speed of 60 at different blade wrap angle and outlet angle is carried out. The analysis of the velocity and the turbulent kinetic energy distribution in different cases, and predicts the external characteristics of the several cases based on the loss analysis method. The study results show that the efficiency of pumps increase with decreasing the outlet angle and increasing the wrapping angle at the design of sewage pumps. According to the analysis, changing the blade outlet Angle has much more influence on the performance of the pump than changing the wrap angle.

A Study on the Internal Flow Characteristics of a Very Low Specific Speed Centrifugal Pump by PTV

2006 ◽  
Vol 9 (1) ◽  
pp. 9-18
Author(s):  
Young-Do Choi ◽  
Jun Matsui ◽  
Junichi Kurokawa ◽  
Young-Ho Lee
Keyword(s):  
Centrifugal Pump ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Low Specific Speed ◽  
Specific Speed

scholarly journals Effects of the impeller–volute tongue interaction on the internal flow in a low-specific-speed centrifugal pump with splitter blades

2017 ◽  
Vol 232 (2) ◽  
pp. 170-180 ◽  
Author(s):  
Yandong Gu ◽  
Shouqi Yuan ◽  
Ji Pei ◽  
Jinfeng Zhang ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Energy Loss ◽  
Centrifugal Pump ◽  
Time History ◽  
Internal Flow ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Impeller Outlet ◽  
Pressure Peak ◽  
Low Specific Speed ◽  
Specific Speed

To investigate the effects of the main blades and splitter blades interacting with the volute tongue on the internal flow in a low-specific-speed centrifugal pump, the Reynolds-averaged Navier–Stokes equation, coupled with SST k-ω turbulence model, is employed to simulate the transient turbulent flow in the whole flow passage. The numerical simulation results have been verified with the experimental measurements by comparing the head and efficiency. The pressure fluctuation caused by impeller–volute tongue interaction, including time–history and frequency characteristics, is calculated and analyzed at five monitoring points adjoining the impeller outlet and tongue, as well as the torque of a single main blade and a single splitter blade. After that, both the energy loss and vorticity distributions on the middle section are discussed when the impeller rotates to four circumferential positions relative to the cutwater. The results show that the maximum pressures at the monitoring points occur before the blades reach the closest circumferential position with respect to the cutwater, and the peak pressure near the trailing edge of splitter blades is larger than main blades. There is only one torque peak of a single blade in one revolution when the angle between the monitoring blade and tongue is about 15°. Additionally, the torque peak arises before the torque valley, but the pressure valley at monitoring points in the impeller comes earlier than the pressure peak. Both the energy loss and vorticity are enlarged around the volute tongue evidently after the blades pass by the cutwater, and the splitter blades produce more unsteadiness and energy dissipation than main blades.

New Centrifugal Pump in Very Low Specific Speed Range

2011 ◽  
Author(s):  
Shusaku Kagawa ◽  
Junichi Kurokawa
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
Cfd Simulation ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Rotating Disk ◽  
Capacity Curve ◽  
Speed Range ◽  
Low Specific Speed ◽  
Specific Speed

In the range of very low specific speed, such as ns < 80 [min.−1, m3/min., m], or Ns < 533 [min.−1, USGPM, ft.], stable head-capacity curve is one of the most important issues. The head-capacity curve of a conventional closed impeller tends to be unstable with a positive slope characteristic in such a very low ns range. To solve this problem, a new type of centrifugal pump “J-groove pump” is proposed and tested in this study. The J-groove pump is composed of a rotating disk mounted with many shallow radial grooves and a circular casing. The experimental results reveal that the proposed J-groove pump is quite effective in the very low specific speed range. The pump head is about 1.2 times higher than that of a conventional centrifugal pump and the head-capacity curve is almost stable, though the efficiency becomes a little lower because of a large friction power of the stationary wall. The cavitation performance is also measured and is shown to be almost same as that of a conventional centrifugal pump. This pump is applicable to high speed pump, as it has no small clearance, high strength due to simple impeller configuration, and easy to assemble. In order to determine the internal flow characteristics of the J-groove pump, CFD simulation is carried out. It is revealed that the high head of the J-groove pump is caused by a strong vortex flow existing in both clearances near the impeller tip over the whole flow range.

scholarly journals Effects of the outlet position of splitter blade on the flow characteristics in low-specific-speed centrifugal pump

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878952 ◽  
Author(s):  
Jinfeng Zhang ◽  
Guidong Li ◽  
Jieyun Mao ◽  
Shouqi Yuan ◽  
Yefei Qu ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Pressure Coefficient ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Suction Side ◽  
Trailing Edge ◽  
Pressure Surface ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Good Agreement

To elucidate the influences of the outlet position of splitter blades on the performance of a low-specific-speed centrifugal pump, two different splitter blade schemes were proposed: one located in the middle of the channel and the other having a deviation angle at the trailing edge of splitter blade toward the suction side of the main blade. Experiments on the model pump with different splitter blade schemes were conducted, and numerical simulations on internal flow characteristics in the impellers were studied by means of the shear stress transport k- ω turbulence model. The results suggest that there is a good agreement between the experimental and numerical results. The splitter blade schemes can effectively optimize the structure of the jet-wake pattern and improve the internal flow states in the impeller channel. In addition, the secondary flow and inlet circulation on the pressure surface of main blade, the flow separation on the suction side of splitter blade, the pressure coefficient distributions on blade surface can achieve an evident amelioration when the trailing edge of splitter blade toward the suction side of the main blade is mounted at an appropriate position.

scholarly journals Internal Flow in a Centrifugal Pump of a Low Specific Speed with Semi-Open Impeller.

2002 ◽  
Vol 68 (668) ◽  
pp. 1174-1180 ◽  
Author(s):  
Jun MATSUI ◽  
Young-Do CHOI ◽  
Junichi KUROKAWA ◽  
Hiroshi IMAMURA ◽  
Manabu HARA
Keyword(s):  
Centrifugal Pump ◽  
Internal Flow ◽  
Low Specific Speed ◽  
Specific Speed

Unsteady Flow in the Vaned Diffuser of a Low Specific Speed Centrifugal Pump With an Unshrouded Impeller

2019 ◽  
Author(s):  
Asuma Ichinose ◽  
Tomoki Takeda ◽  
Kazuyoshi Miyagawa ◽  
Yohei Ogawa ◽  
Hideyo Negishi ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Internal Flow ◽  
The Other ◽  
Vaned Diffuser ◽  
Design Point ◽  
Other Hand ◽  
Impeller Outlet ◽  
Outlet Flow ◽  
Low Specific Speed ◽  
Specific Speed

Abstract The unsteady internal flow in a low specific speed centrifugal pump was experimentally and numerically investigated. Unshrouded impellers enable high head designs but on the other hand, they exhibit complicated internal flow and an efficiency decline compared to shrouded impellers. Furthermore, the complicated impeller outlet flow induces unsteady internal flow in the vaned diffuser. Therefore, a detailed investigation of the internal flow is required in order to increase the efficiency of these low specific speed centrifugal pumps. The aims of this paper are to clarify the loss mechanisms in the impeller and to investigate the effect of impeller outlet flow to the diffuser internal flow at the design point. The detailed pump internal flow is investigated using unsteady computation, which enables the computation of the 3D flow pattern. The reversed flow and the secondary flow are induced by the tip leakage flow, and this creates a high loss region in the blade-to-blade region. On the other hand, the mixing effect is remarkable at the impeller outlet, and this affects the creation of the wake. This flow behavior makes the internal flow of the diffuser unsteady and the diffuser performance fluctuates due to the impeller wake at the design point.

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