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Sample records for centrifugal blood pump

  1. [Hemodynamic analysis of a centrifugal blood pump].

    Science.gov (United States)

    Wang, Yang; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Li, Qilei; Xu, Liang

    2015-01-01

    This paper built the mathematical model of a centrifugal blood pump, which was designed by ourselves, combined it with that of the human cardiovascular system and simulated the coupling system using Matlab. Then we set up the experiment platform, linked the blood pump to mock human cardiovascular system in case of three-stage heart failure, and measured aortic pressure and flow under different speed. The comparison between experiment results and simulation results not only indicates the coupling model is correct and the blood pump works well, but also shows that with the increase of blood pump speed, the pulsation of aortic pressure and flow will be reduced, this situation will affect the structure and function of blood vessels. PMID:26027287

  2. A multiple disk centrifugal pump as a blood flow device.

    Science.gov (United States)

    Miller, G E; Etter, B D; Dorsi, J M

    1990-02-01

    A multiple disk, shear force, valveless centrifugal pump was studied to determine its suitability as a blood flow device. A pulsatile version of the Tesla viscous flow turbine was designed by modifying the original steady flow pump concept to produce physiological pressures and flows with the aid of controlling circuitry. Pressures and flows from this pump were compared to a Harvard Apparatus pulsatile piston pump. Both pumps were connected to an artificial circulatory system. Frequency and systolic duration were varied over a range of physiological conditions for both pumps. The results indicated that the Tesla pump, operating in a pulsatile mode, is capable of producing physiologic pressures and flows similar to the Harvard pump and other pulsatile blood pumps. PMID:2312140

  3. Centrifugal pumps

    CERN Document Server

    Anderson, HH

    1981-01-01

    Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

  4. Centrifugal pumps

    CERN Document Server

    Gülich, Johann Friedrich

    2014-01-01

    This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

  5. [Numerical assessment of impeller features of centrifugal blood pump based on fast hemolysis approximation model].

    Science.gov (United States)

    Shou, Chen; Guo, Yongjun; Su, Lei; Li, Yongqian

    2014-12-01

    The impeller profile, which is one of the most important factors, determines the creation of shear stress which leads to blood hemolysis in the internal flow of centrifugal blood pump. The investigation of the internal flow field in centrifugal blood pump and the estimation of the hemolysis within different impeller profiles will provide information to improve the performance of centrifugal blood pump. The SST kappa-omega with low Reynolds correction was used in our laboratory to study the internal flow fields for four kinds of impellers of centrifugal blood pump. The flow fields included distributions of pressure field, velocity field and shear stress field. In addition, a fast numerical hemolysis approximation was adopted to calculate the normalized index of hemolysis (NIH). The results indicated that the pressure field distribution in all kinds of blood pump were reasonable, but for the log spiral impeller pump, the vortex and backflow were much lower than those of the other pumps, and the high shear stress zone was just about 0.004%, and the NIH was 0.0089. PMID:25868241

  6. Design optimization of flow channel and performance analysis for a new-type centrifugal blood pump

    Science.gov (United States)

    Ji, J. J.; Luo, X. W.; Y Wu, Q.

    2013-12-01

    In this paper, a new-type centrifugal blood pump, whose impeller is suspended inside a pump chamber with hydraulic bearings, is presented. In order to improve the hydraulic performance of the pump, an internal flow simulation is conducted to compare the effects of different geometrical parameters of pump flow passage. Based on the numerical results, the pumps can satisfy the operation parameters and be free of hemolysis. It is noted that for the pump with a column-type supporter at its inlet, the pump head and hydraulic efficiency decreases compared to the pump with a step-type support structure. The performance drop is caused by the disturbed flow upstream impeller inlet. Further, the unfavorable flow features such as reverse flow and low velocity in the pump may increases the possibility of thrombus. It is also confirmed that the casing shape can little influence pump performance. Those results are helpful for design optimization in blood pump development.

  7. Numerical analysis of the internal flow field in screw centrifugal blood pump based on CFD

    Science.gov (United States)

    Han, W.; Han, B. X.; Y Wang, H.; Shen, Z. J.

    2013-12-01

    As to the impeller blood pump, the high speed of the impeller, the local high shear force of the flow field and the flow dead region are the main reasons for blood damage. The screw centrifugal pump can effectively alleviate the problems of the high speed and the high shear stress for the impeller. The softness and non-destructiveness during the transfer process can effectively reduce the extent of the damage. By using CFD software, the characteristics of internal flow are analyzed in the screw centrifugal pump by exploring the distribution rules of the velocity, pressure and shear deformation rate of the blood when it flows through the impeller and the destructive effects of spiral blades on blood. The results show that: the design of magnetic levitation solves the sealing problems; the design of regurgitation holes solves the problem of the flow dead zone; the magnetic levitated microcirculation screw centrifugal pump can effectively avoid the vortex, turbulence and high shear forces generated while the blood is flowing through the pump. Since the distribution rules in the velocity field, pressure field and shear deformation rate of the blood in the blood pump are comparatively uniform and the gradient change is comparatively small, the blood damage is effectively reduced.

  8. Numerical Analysis of the FDA Centrifugal Blood Pump

    OpenAIRE

    Marinova, V.; Kerroumi, I.; Lintermann, Andreas; Göbbert, Jens Henrik; Moulinec, C.; Rible, S.; Fournier, Y.; Behbahani, M.

    2016-01-01

    Ventricular Assist Devices (VADs) are commonly implanted to assist patients suffering fromheart diseases. They provide long- and short-term support for the human heart and help patientsto recover from heart attacks and from congestive heart failure. It is essential to design bloodsensitiveVADs to minimise the risk of hemolysis and thrombosis. The blood pump, however,must operate at a wide range of flow rates and pressure heads which makes a low-risk design achallenging task. In this study the...

  9. Evaluation of erythrocyte flow at a bearing gap in a hydrodynamically levitated centrifugal blood pump.

    Science.gov (United States)

    Murashige, Tomotaka; Kosaka, Ryo; Sakota, Daisuke; Nishida, Masahiro; Kawaguchi, Yasuo; Yamane, Takashi; Maruyama, Osamu

    2015-01-01

    We have developed a hydrodynamically levitated centrifugal blood pump for extracorporeal circulatory support. In the blood pump, a spiral groove bearing was adopted for a thrust bearing. In the spiral groove bearing, separation of erythrocytes and plasma by plasma skimming has been postulated to occur. However, it is not clarified that plasma skimming occurs in a spiral groove bearing. The purpose of this study is to verify whether plasma skimming occurs in the spiral groove bearing of a hydrodynamically levitated centrifugal blood pump. For evaluation of plasma skimming in the spiral groove bearing, an impeller levitation performance test using a laser focus displacement meter and a microscopic visualization test of erythrocyte flow using a high-speed microscope were conducted. Bovine blood diluted with autologous plasma to adjust hematocrit to 1.0% was used as a working fluid. Hematocrit on the ridge region in the spiral groove bearing was estimated using image analysis. As a result, hematocrits on the ridge region with gaps of 45 μm, 31 μm, and 25 μm were calculated as 1.0%, 0.6%, and 0.3%, respectively. Maximum skimming efficiency in this study was calculated as 70% with a gap of 25 μm. We confirmed that separation of erythrocyte and plasma occurred in the spiral groove bearing with decrease in bearing gap in a hydrodynamically levitated centrifugal blood pump. PMID:26736252

  10. Numerical investigation of the effect of blade geometry on blood trauma in a centrifugal blood pump.

    Science.gov (United States)

    Chan, W K; Wong, Y W; Ding, Y; Chua, L P; Yu, S C M

    2002-09-01

    Fluid dynamic forces in centrifugal blood pump impellers are of key importance in destruction of red blood cells (RBCs) because high rotational speed leads to strong interaction between the impeller and the RBCs. In this paper, three-dimensional models of five different blade geometries are investigated numerically using the commercial software CFX-TASCflow, and the streaklines of RBCs are obtained using the Lagrangian particle tracking method. In reality, RBCs pass through the pump along complicated paths resulting in a highly irregular loading condition for each RBC. In order to enable the prediction of blood damage under the action of these complex-loading conditions, a cumulative damage model for RBCs was adopted in this paper. The numerically simulated percent hemoglobin (%HB) released as RBCs traversed the impeller and volute was examined. It was observed that the residence time of particles in the blade passage is a critical factor in determining hemolytic effects. This, in turn, is a function of the blade geometry. In addition, it was observed that the volute profile is an important influence on the computed HB% released. PMID:12197935

  11. Numerical study of a centrifugal blood pump with different impeller profiles.

    Science.gov (United States)

    Song, Guoliang; Chua, Leok Poh; Lim, Tau Meng

    2010-01-01

    Computational fluid dynamic simulations of the Kyoto-NTN magnetically suspended centrifugal blood pump with 16 forward-bending blades (16FB), 16 straight blades (16SB), and eight backward-bending blades (8BB) impellers were performed in this study. Commercial CFD software package FLUENT were used as the solver. The purpose of this study is to find out how the impeller blade profiles affect the inner flow and the performance of the centrifugal blood pump. The simulations were carried out with the same impeller rotating speed of 2,000 rpm and pump flow rate of 5 L/min to compare the three pump models. It was found that the 16SB impeller can produce higher pressure head than the 16FB and 8BB impellers under the same impeller rotating speed and pump flow rate. The flow particle tracing was carried out to estimate the blood damage level caused by the three different impeller profiles. It was found that the 16FB and 8BB models have caused the highest and lowest blood damage, respectively. The 16SB is recommended among the three pumps because it can generate the highest pressure head and induce mild blood damage index, although it was higher than that of the 8BB model. PMID:20019595

  12. Development of a compact, sealless, tripod supported, magnetically driven centrifugal blood pump.

    Science.gov (United States)

    Yuhki, A; Nogawa, M; Takatani, S

    2000-06-01

    In this study, a tripod supported sealless centrifugal blood pump was designed and fabricated for implantable application using a specially designed DC brushless motor. The tripod structure consists of 3 ceramic balls mounted at the bottom surface of the impeller moving in a polyethylene groove incorporated at the bottom pump casing. The follower magnet inside the impeller is coupled to the driver magnet of the motor outside the bottom pump casing, thus allowing the impeller to slide-rotate in the polyethylene groove as the motor turns. The pump driver has a weight of 230 g and a diameter of 60 mm. The acrylic pump housing has a weight of 220 g with the priming volume of 25 ml. At the pump rpm of 1,000 to 2,200, the generated head pressure ranged from 30 to 150 mm Hg with the maximum system efficiency being 12%. When the prototype pump was used in the pulsatile mock loop to assist the ventricle from its apex to the aorta, a strong correlation was obtained between the motor current and bypass flow waveforms. The waveform deformation index (WDI), defined as the ratio of the fundamental to the higher order harmonics of the motor current power spectral density, was computed to possibly detect the suction occurring inside the ventricle due to the prototype centrifugal pump. When the WDI was kept under the value of 0.20 by adjusting the motor rpm, it was successful in suppressing the suction due to the centrifugal pump in the ventricle. The prototype sealless, centrifugal pump together with the control method based on the motor current waveform analysis may offer an intermediate support of the failing left or right ventricle bridging to heart transplantation. PMID:10886073

  13. Prediction of shear stress-related hemolysis in centrifugal blood pumps by computational fluid dynamics

    Institute of Scientific and Technical Information of China (English)

    WANG Fangqun; LI Lan; FENG Zhigang; QIAN Kunxi

    2005-01-01

    A quantitative evaluation of shear stress-related hemolysis in centrifugal blood pumps with different impeller designs has been investigated. Computational fluid dynamics (CFD) is applied to track the shear stress history of the streamlines of red cells. The power law model of the relations among the hemolysis, shear stress and exposure time is used to evaluate the hemolysis in the pumps.Hemolysis tests are also conducted to verify the estimations. Both the estimations and experimentally measured hemolysis levels show that the hemolysis in the streamlined impeller pump developed by the authors is lower than the pump with straight-vane under the same boundary conditions. The approach is proved to be acceptable and practical to predict hemolysis levels of blood pumps.

  14. Numerical study of a bio-centrifugal blood pump with straight impeller blade profiles.

    Science.gov (United States)

    Song, Guoliang; Chua, Leok Poh; Lim, Tau Meng

    2010-02-01

    Computational fluid dynamic simulations of the flow in the Kyoto-NTN (Kyoto University, Kyoto, Japan) magnetically suspended centrifugal blood pump with a 16-straight-bladed impeller were performed in the present study. The flow in the pump was assumed as unsteady and turbulent, and blood was treated as a Newtonian fluid. At the impeller rotating speed of 2000 rpm and flow rate of 5 L/min, the pump produces a pressure head of 113.5 mm Hg according to the simulation. It was found that the double volute of the pump has caused symmetrical pressure distribution in the volute passages and subsequently caused symmetrical flow patterns in the blade channels. Due to the tangentially increasing pressure in the volute passages, the flow through the blade channels initially increases at the low-pressure region and then decreases due to the increased pressure. The reverse flow and vortices have been identified in the impeller blade channels. The high shear stress of the flow in the pump mainly occurred at the inlet and outlet of the blade channels, the beginning of the volute passages and the regions around the tips of the cutwater and splitter plate. Higher shear stress is obtained when the tips of the cutwater and splitter plate are located at the impeller blade trailing edges than when they are located at the middle of the impeller blade channel. It was found that the blood damage index assessed based on the blood corpuscle path tracing of the present pump was about 0.94%, which has the same order of magnitude as those of the clinical centrifugal pumps reported in the literature. PMID:19817732

  15. A new model of centrifugal blood pump for cardiopulmonary bypass: design improvement, performance, and hemolysis tests.

    Science.gov (United States)

    Leme, Juliana; Fonseca, Jeison; Bock, Eduardo; da Silva, Cibele; da Silva, Bruno Utiyama; Dos Santos, Alex Eugênio; Dinkhuysen, Jarbas; Andrade, Aron; Biscegli, José F

    2011-05-01

    A new model of blood pump for cardiopulmonary bypass (CPB) application has been developed and evaluated in our laboratories. Inside the pump housing is a spiral impeller that is conically shaped and has threads on its surface. Worm gears provide an axial motion of the blood column. Rotational motion of the conical shape generates a centrifugal pumping effect and improves pumping performance. One annular magnet with six poles is inside the impeller, providing magnetic coupling to a brushless direct current motor. In order to study the pumping performance, a mock loop system was assembled. Mock loop was composed of Tygon tubes (Saint-Gobain Corporation, Courbevoie, France), oxygenator, digital flowmeter, pressure monitor, electronic driver, and adjustable clamp for flow control. Experiments were performed on six prototypes with small differences in their design. Each prototype was tested and flow and pressure data were obtained for rotational speed of 1000, 1500, 2000, 2500, and 3000 rpm. Hemolysis was studied using pumps with different internal gap sizes (1.35, 1.45, 1.55, and 1.7 mm). Hemolysis tests simulated CPB application with flow rate of 5 L/min against total pressure head of 350 mm Hg. The results from six prototypes were satisfactory, compared to the results from the literature. However, prototype #6 showed the best results. Best hemolysis results were observed with a gap of 1.45 mm, and showed a normalized index of hemolysis of 0.013 g/100 L. When combined, axial and centrifugal pumping principles produce better hydrodynamic performance without increasing hemolysis. PMID:21595709

  16. Microhaemodynamics within the blade tip clearance of a centrifugal turbodynamic blood pump.

    Science.gov (United States)

    Antaki, J F; Diao, C-G; Shu, F-J; Wu, J-C; Zhao, R; Kameneva, M V

    2008-05-01

    A persistent challenge facing the quantitative design of turbodynamic blood pumps is the great disparity of spatial scales between the primary and auxiliary flow paths. Fluid passages within journals and adjacent to the blade tips are often on the scale of several blood cells, confounding the application of macroscopic continuum models. Yet, precisely in these regions there exists the highest shear stress, which is most likely to cause cellular trauma. This disparity has motivated these microscopic studies to visualize the kinematics of the blood cells within the small clearances of a miniature turbodynamic blood pump. A transparent model of a miniature centrifugal pump having an adjustable tip clearance (50-200 microm) was prepared for direct optical visualization of the region between the impeller blade tip and the stationary housing. Synchronized images of the blood cells were obtained by a microscopic visualization system, consisting of an inverted microscope fitted with long-working-distance objective lens (40x), mercury lamp, and high-resolution charge-coupled device camera electronically triggered by the rotation of the impeller. Experiments with 7 microm fluorescent particles revealed the influence of the gap dimension on the trajectory across the blade thickness. The lateral component of velocity (perpendicular to the blade) was dramatically enhanced in the 50 microm gap compared with the 200 microm gap, thereby reducing the exposure time. Studies with diluted bovine blood (Ht = 0.5 per cent) showed that the concentration of cells traversing the gap is also reduced dramatically (30 per cent) as the blade tip clearance is reduced from 200 microm to 50 microm. These results motivate further investigation into the microfluidic phenomena responsible for cellular trauma within turbodynamic blood pumps. PMID:18595366

  17. Left ventricular volume unloading with axial and centrifugal rotary blood pumps.

    Science.gov (United States)

    Giridharan, Guruprasad A; Koenig, Steven C; Soucy, Kevin G; Choi, Young; Pirbodaghi, Tohid; Bartoli, Carlo R; Monreal, Gretel; Sobieski, Michael A; Schumer, Erin; Cheng, Allen; Slaughter, Mark S

    2015-01-01

    Axial (AX) and centrifugal (CFG) rotary blood pumps have gained clinical acceptance for the treatment of advanced heart failure. Differences between AX and CFG designs and mechanism of blood flow delivery may offer clinical advantages. In this study, pump characteristics, and acute physiologic responses during support with AX (HeartMate II) and CFG (HVAD) left ventricular assist devices (LVAD) were investigated in mock loop and chronic ischemic heart failure bovine models. In the mock loop model, pump performance was characterized over a range of pump speeds (HeartMate II: 7,000-11,000 rpm, HVAD: 2,000-3,600 rpm) and fluid viscosities (2.7 cP, 3.2 cP, 3.7 cP). In the ischemic heart failure bovine model, hemodynamics, echocardiography, and end-organ perfusion were investigated. CFG LVAD had a flatter HQ curve, required less power, and had a more linear flow estimation relation than AX LVAD. The flow estimation error for the AX LVAD (±0.9 L/min at 2.7 cP, ±0.7 L/min at 3.2 cP, ±0.8 L/min at 3.7 cP) was higher than the CFG LVAD (±0.5 L/min at 2.7 cP, ±0.2 L/min at 3.2 cP, ±0.5 L/min at 3.7 cP). No differences in acute hemodynamics, echocardiography, or end-organ perfusion between AX and CFG LVAD over a wide range of support were statistically discernible. These findings suggest no pronounced acute differences in LV volume unloading between AX and CFG LVAD. PMID:25635936

  18. Bearing gap adjustment for improvement of levitation performance in a hydrodynamically levitated centrifugal blood pump.

    Science.gov (United States)

    Kosaka, Ryo; Yoshida, Fumihiko; Nishida, Masahiro; Maruyama, Osamu; Kawaguchi, Yasuo; Yamane, Takashi

    2015-01-01

    The purpose of the present study is to investigate a bearing gap adjustment for improvement of levitation performance in a hydrodynamically levitated centrifugal blood pump to realize a blood pump with a low hemolysis level. The impeller levitates axially by balancing a gravitational force, buoyancy, a magnetic force, and hydrodynamic forces on the top and bottom sides of the impeller. To adjust the levitation position of the impeller, the balance of acting forces on the impeller was adjusted by changing the shroud area on the bottom impeller. Three pumps having various shroud area were prepared as tested models: 817 mm(2) (HH-S), 875 mm(2) (HH-M) and 931 mm(2) (HH-L). First, for evaluating the bearing gap adjustment, the bearing gap was estimated by calculating a balancing position of the acting forces on the impeller. We actually measured the gravitational force, buoyancy and the magnetic force, and numerically analyzed hydrodynamic forces on the top and bottom sides of the impeller. Second, to verify accuracy of the estimated bearing gap, the measurement test of the bearing gap was performed. Finally, an in-vitro hemolysis test was performed to evaluate a hemolysis level of the pump. As a result, bottom bearing gaps were estimated as 40 μm (HH-S), 60 μm (HH-M) and 238 μm (HH-L). In the measurement test, bottom bearing gaps were measured as 63 μm (HH-S), 219 μm (HH-M), and 231 μm (HH-L). The estimated bearing gaps had positively correlated with the measured bearing gaps in relation to the shroud area on the impeller. In the hemolysis test, hemolysis level in every model was almost equivalent to that of BPX-80, when the bearing gap was adjusted greater than 60 μm. We could adjust the bearing gap by changing the shroud area on the impeller for improvement of levitation performance to realize a blood pump with a low hemolysis level. PMID:26736996

  19. [Research on magnetic coupling centrifugal blood pump control based on a self-tuning fuzzy PI algorithm].

    Science.gov (United States)

    Yang, Lei; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Wang, Wei; Zhang, Haibo; Han, Lu; Xu, Liang

    2014-10-01

    The purpose of this paper is to report the research and design of control system of magnetic coupling centrifugal blood pump in our laboratory, and to briefly describe the structure of the magnetic coupling centrifugal blood pump and principles of the body circulation model. The performance of blood pump is not only related to materials and structure, but also depends on the control algorithm. We studied the algorithm about motor current double-loop control for brushless DC motor. In order to make the algorithm adjust parameter change in different situations, we used the self-tuning fuzzy PI control algorithm and gave the details about how to design fuzzy rules. We mainly used Matlab Simulink to simulate the motor control system to test the performance of algorithm, and briefly introduced how to implement these algorithms in hardware system. Finally, by building the platform and conducting experiments, we proved that self-tuning fuzzy PI control algorithm could greatly improve both dynamic and static performance of blood pump and make the motor speed and the blood pump flow stable and adjustable. PMID:25764720

  20. Blood flow/pump rotation ratio as an artificial lung performance monitoring tool during extracorporeal respiratory support using centrifugal pumps

    OpenAIRE

    Park, Marcelo; Mendes, Pedro Vitale; Hirota, Adriana Sayuri; dos Santos, Edzangela Vasconcelos; Costa, Eduardo Leite Vieira; Azevedo, Luciano Cesar Pontes

    2015-01-01

    Objective To analyze the correlations of the blood flow/pump rotation ratio and the transmembrane pressure, CO2 and O2 transfer during the extracorporeal respiratory support. Methods Five animals were instrumented and submitted to extracorporeal membrane oxygenation in a five-step protocol, including abdominal sepsis and lung injury. Results This study showed that blood flow/pump rotations ratio variations are dependent on extracorporeal membrane oxygenation blood flow in a positive logarithm...

  1. Centrifugal pumps for rocket engines

    Science.gov (United States)

    Campbell, W. E.; Farquhar, J.

    1974-01-01

    The use of centrifugal pumps for rocket engines is described in terms of general requirements of operational and planned systems. Hydrodynamic and mechanical design considerations and techniques and test procedures are summarized. Some of the pump development experiences, in terms of both problems and solutions, are highlighted.

  2. Evaluation of a Spiral Groove Geometry for Improvement of Hemolysis Level in a Hydrodynamically Levitated Centrifugal Blood Pump.

    Science.gov (United States)

    Murashige, Tomotaka; Kosaka, Ryo; Sakota, Daisuke; Nishida, Masahiro; Kawaguchi, Yasuo; Yamane, Takashi; Maruyama, Osamu

    2015-08-01

    The purpose of this study is to evaluate a spiral groove geometry for a thrust bearing to improve the hemolysis level in a hydrodynamically levitated centrifugal blood pump. We compared three geometric models: (i) the groove width is the same as the ridge width at any given polar coordinate (conventional model); (ii) the groove width contracts inward from 9.7 to 0.5 mm (contraction model); and (iii) the groove width expands inward from 0.5 to 4.2 mm (expansion model). To evaluate the hemolysis level, an impeller levitation performance test and in vitro hemolysis test were conducted using a mock circulation loop. In these tests, the driving conditions were set at a pressure head of 200 mm Hg and a flow rate of 4.0 L/min. As a result of the impeller levitation performance test, the bottom bearing gaps of the contraction and conventional models were 88 and 25 μm, respectively. The impeller of the expansion model touched the bottom housing. In the hemolysis test, the relative normalized index of hemolysis (NIH) ratios of the contraction model in comparison with BPX-80 and HPM-15 were 0.6 and 0.9, respectively. In contrast, the relative NIH ratios of the conventional model in comparison with BPX-80 and HPM-15 were 9.6 and 13.7, respectively. We confirmed that the contraction model achieved a large bearing gap and improved the hemolysis level in a hydrodynamically levitated centrifugal blood pump. PMID:26146791

  3. Centrifugal pumps and allied machinery

    CERN Document Server

    Anderson, HH

    1994-01-01

    This book will be of vital interest to all engineers and designers concerned with centrifugal pumps and turbines. Including statistical information derived from 20000 pumps and 700 turbines with capacities of 5gpm to 5000000gpm, this book offers the widest range and scope of information currently available. Statistical analyses suggest practical methods of increasing pump performance and provide valuable data for new design aspects.

  4. Implantable centrifugal blood pump with dual impeller and double pivot bearing system: electromechanical actuator, prototyping, and anatomical studies.

    Science.gov (United States)

    Bock, Eduardo; Antunes, Pedro; Leao, Tarcisio; Uebelhart, Beatriz; Fonseca, Jeison; Leme, Juliana; Utiyama, Bruno; da Silva, Cibele; Cavalheiro, Andre; Filho, Diolino Santos; Dinkhuysen, Jarbas; Biscegli, Jose; Andrade, Aron; Arruda, Celso

    2011-05-01

    An implantable centrifugal blood pump has been developed with original features for a left ventricular assist device. This pump is part of a multicenter and international study with the objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations and wear evaluation in bearing system were performed followed by prototyping and in vitro tests. In addition, previous blood tests for assessment of normalized index of hemolysis show results of 0.0054±2.46 × 10⁻³ mg/100 L. An electromechanical actuator was tested in order to define the best motor topology and controller configuration. Three different topologies of brushless direct current motor (BLDCM) were analyzed. An electronic driver was tested in different situations, and the BLDCM had its mechanical properties tested in a dynamometer. Prior to evaluation of performance during in vivo animal studies, anatomical studies were necessary to achieve the best configuration and cannulation for left ventricular assistance. The results were considered satisfactory, and the next step is to test the performance of the device in vivo. PMID:21595708

  5. 磁液悬浮式离心血泵实验研究%The Experimental Research on Magnetic Fluid Suspension Centrifugal Blood Pump

    Institute of Scientific and Technical Information of China (English)

    姜洋; 高航; 王伟; 苏静静; 刘雯

    2012-01-01

    Magnetic fluid suspension centrifugal blood pump is the core component of the third generation assisted heart system. The performance of the blood pump is a very important parameter of the assisted heart system. In this paper, we study the performance of a new kind of magnetic fluid suspension centrifugal blood pump by designing an experimental system and evaluating this blood pump, providing the experimental data for the research of the magnetic fluid suspension centrifugal blood pump.%磁液悬浮式离心血泵是第三代人工辅助心脏系统的核心部件,血泵的好坏直接影响到整个系统的工作性能。本文针对一种新型磁液悬浮式离心血泵开展血泵性能测试的实验研究,通过设计实验系统测试获得血泵各项性能参数,并对此种新型血泵的综合性能进行评价,为新型磁液悬浮式离心血泵的研制工作提供实验依据。

  6. Effect of a bearing gap on hemolytic property in a hydrodynamically levitated centrifugal blood pump with a semi-open impeller.

    Science.gov (United States)

    Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu; Yambe, Tomoyuki; Imachi, Kou; Yamane, Takashi

    2013-01-01

    We have developed a hydrodynamically levitated centrifugal blood pump with a semi-open impeller for long-term circulatory assist. The pump uses hydrodynamic bearings to enhance durability and reliability without additional displacement-sensors or control circuits. However, a narrow bearing gap of the pump has a potential for hemolysis. The purpose of this study is to develop the hydrodynamically levitated centrifugal blood pump with a semi-open impeller, and to evaluate the effect of a bearing gap on hemolytic property. The impeller levitates using a spiral-groove type thrust bearing, and a herringbone-groove type radial bearing. The pump design was improved by adopting a step type thrust bearing and optimizing the pull-up magnetic force. The pump performance was evaluated by a levitation performance test, a hemolysis test and an animal experiment. In these tests, the bearing gap increased from 1 to 63 μm. In addition, the normalized index of hemolysis (NIH) improved from 0.415 to 0.005 g/100 l, corresponding to the expansion of the bearing gap. In the animal experiment for 24 h, the plasma-free hemoglobin remained within normal ranges (<4.0 mg/dl). We confirmed that the hemolytic property of the pump was improved to the acceptable level by expanding the bearing gap greater than 60 μm. PMID:23442235

  7. Performance of a Centrifugal Slurry Pump

    OpenAIRE

    Hawas Yahya Bajawi; Basharat Salim; Ziyadh Suhibani

    2014-01-01

    The aim of this study was to experimentally investigate the effect of speed, concentration and size of slurry on the performance of a centrifugal pump. For this purpose a facility was built where the performance of a centrifugal slurry pump was examined using aggregate slurry. Three sizes of slurry with three concentrations and at three impeller speeds were used for the performance investigations of a centrifugal slurry pump. As a reference performance the performance of centrifugal slurry pu...

  8. Engineering Aspects in Blood Pump Development

    Science.gov (United States)

    Golding, Leonard; Veres, Joseph P.

    1997-01-01

    NASA turbomachinery computer codes assisted in the design of the Cleveland Clinic Foundation's centrifugal bladed blood pump. The codes were originally developed for the aerospace industry, but are applicable to the blood pump because of a high degree of synergy with this application. Traditional turbomachinery design criteria were used in the design of the blood pump centrifugal impeller and volute casing. The fluid dynamic performance of the blood pump is meeting the engineering design goals of flow rate and pressure rise.

  9. Effect of Impeller Geometry on Lift-Off Characteristics and Rotational Attitude in a Monopivot Centrifugal Blood Pump.

    Science.gov (United States)

    Nishida, Masahiro; Nakayama, Kento; Sakota, Daisuke; Kosaka, Ryo; Maruyama, Osamu; Kawaguchi, Yasuo; Kuwana, Katsuyuki; Yamane, Takashi

    2016-06-01

    The effect of the flow path geometry of the impeller on the lift-off and tilt of the rotational axis of the impeller against the hydrodynamic force was investigated in a centrifugal blood pump with an impeller supported by a single-contact pivot bearing. Four types of impeller were compared: the FR model with the flow path having both front and rear cutouts on the tip, the F model with the flow path having only a front cutout, the R model with only a rear cutout, and the N model with a straight flow path. First, the axial thrust and the movement about the pivot point, which was loaded on the surface of the impeller, were calculated using computational fluid dynamics (CFD) analysis. Next, the lift-off point and the tilt of the rotational axis of the impeller were measured experimentally. The CFD analysis showed that the axial thrust increased gently in the FR and R models as the flow rate increased, whereas it increased drastically in the F and N models. This difference in axial thrust was likely from the higher pressure caused by the smaller circumferential velocity in the gap between the top surface of the impeller and the casing in the FR and R models than in the F and N models, which was caused by the rear cutout. These results corresponded with the experimental results showing that the impellers lifted off in the F and N models as the flow rate increased, whereas it did not in the FR and R models. Conversely, the movement about the pivot point increased in the direction opposite the side with the pump outlet as the flow rate increased. However, the tilt of the rotational axis of the impeller, which oriented away from the pump outlet, was less than 0.8° in any model under any conditions, and was considered to negligibly affect the rotational attitude of the impeller. These results confirm that a rear cutout prevents lift-off of the impeller caused by a decrease in the axial thrust. PMID:27097844

  10. Cavitation Effects in Centrifugal Pumps- A Review

    Directory of Open Access Journals (Sweden)

    Maxime Binama

    2016-05-01

    Full Text Available Cavitation is one of the most challenging fluid flow abnormalities leading to detrimental effects on both the centrifugal pump flow behaviors and physical characteristics. Centrifugal pumps’ most low pressure zones are the first cavitation victims, where cavitation manifests itself in form of pitting on the pump internal solid walls, accompanied by noise and vibration, all leading to the pump hydraulic performance degradation. In the present article, a general description of centrifugal pump performance and related parameters is presented. Based on the literature survey, some light were shed on fundamental cavitation features; where different aspects relating to cavitation in centrifugal pumps were briefly discussed

  11. Real-Time Observation of Thrombus Growth Process in an Impeller of a Hydrodynamically Levitated Centrifugal Blood Pump by Near-Infrared Hyperspectral Imaging.

    Science.gov (United States)

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Fujiwara, Tatsuki; Nishida, Masahiro; Maruyama, Osamu

    2015-08-01

    Understanding the thrombus formation in cardiovascular devices such as rotary blood pumps is the most important issue in developing more hemocompatible devices. The objective of this study was to develop a hyperspectral imaging (HSI) method to visualize the thrombus growth process within a rotary blood pump and investigate the optical properties of the thrombus. An in vitro thrombogenic test was conducted using fresh porcine blood and a specially designed hydrodynamically levitated centrifugal blood pump with a transparent bottom. The pump rotating at 3000 rpm circulated the blood at 1.0 L/min. The bottom surface of the pump was illuminated with white light pulsed at the same frequency as the pump rotation, and the backward-scattered light was imaged using the HSI system. Using stroboscopic HSI and an image construction algorithm, dynamic spectral imaging at wavelengths ranging from 608 to 752 nm within the rotating pump was achieved. After completing the experiment, we collected the red thrombus formed in the pump impeller and quantified the thrombus hemoglobin concentration (Hbthrombus ). The spectrum changed around the center of the impeller, and the area of change expanded toward the impeller flow path. The shape corresponded approximately to the shape of the thrombus. The spectrum change indicated that the light scattering derived from red blood cells decreased. The Hbthrombus was 4.7 ± 1.3 g/dL versus a total hemoglobin of 13 ± 0.87 g/dL. The study revealed that Hbthrombus was reduced by the surrounding blood flow. PMID:26234451

  12. 基于溶血性能的离心式旋转血泵设计%Design of Centrifugal Blood Pump Based on Hemolysis Estimation

    Institute of Scientific and Technical Information of China (English)

    阮晓东; 陈松松; 钱伟; 邹俊; 付新

    2011-01-01

    Hemolytic performance is an important index of blood pump. Based on average shear stress model,we optimized the parameters of the impeller to reduce the time of red blood cells flowing through the impeller and the average shear stress they suffered in the process. Computational fluid dynamic simulations of the flow in the centrifugal blood pump were used in the present study. The traces and flow parameters of red cells in the blood pump were acquired. With the help of empirical formulas of hemolysis, hemolytic performances of pump in different flow rates were acquired. The predicted blood damage index was between 0. 006 and 0. 015, which showed that hemolysis performance of the blood pump is satisfactory. In conclusion the design method for blood pump is applicable.%溶血性能是衡量血泵性能的一个重要指标.基于平均剪切应力模型,通过减少红细胞流经叶轮的时间和降低它在此过程中所受平均剪切应力的方法,对离心血泵进行设计,进而改善溶血性能.采用商用流体仿真软件Fluent,对血泵内的三维不可压湍流流场进行数值模拟,得到红细胞在血泵内的流动迹线和流动参数;应用溶血估算公式,分析不同流量下血泵的溶血性能,计算得到溶血估算值在0.006-0.015之间,有较好的溶血性能,满足血泵对溶血性能的要求.

  13. Return Vane Installed in Multistage Centrifugal Pump

    OpenAIRE

    Miyano, Masafumi; Kanemoto, Toshiaki; Kawashima, Daisuke; Wada, Akihiro; Hara, Takashi; Sakoda, Kazuyuki

    2008-01-01

    To optimize the stationary components in the multistage centrifugal pump, the effects of the return vane profile on the performances of the multistage centrifugal pump were investigated experimentally, taking account of the inlet flow conditions for the next stage impeller. The return vane, whose trailing edge is set at the outer wall position of the annular channel downstream of the vane and which discharges the swirl-less flow, gives better pump performances. By equipping such return vane w...

  14. CFD Analysis of Centrifugal Pump: A Review

    OpenAIRE

    Narayan P. Jaiswal

    2014-01-01

    The main objective of this work is to understand role of the computational fluid dynamics (CFD) technique in analyzing and predicting the performance of centrifugal pump. Computational Fluid Dynamics (CFD) is the present day state-of-art technique for fluid flow analysis. The critical review of CFD analysis of CFD analysis of centrifugal pump along with future scope for further improvement is presented in this paper. Different solver like ANSYS-CFX, FLUENT etc can be used for ...

  15. Performance of a Centrifugal Slurry Pump

    Directory of Open Access Journals (Sweden)

    Hawas Yahya Bajawi

    2014-02-01

    Full Text Available The aim of this study was to experimentally investigate the effect of speed, concentration and size of slurry on the performance of a centrifugal pump. For this purpose a facility was built where the performance of a centrifugal slurry pump was examined using aggregate slurry. Three sizes of slurry with three concentrations and at three impeller speeds were used for the performance investigations of a centrifugal slurry pump. As a reference performance the performance of centrifugal slurry pump was also tested with clean water. The performance of pump has been reported as variations of head, power and efficiency at various flow rates along with the system characteristics of the pump. The results reveal that the pump performance is grossly affected by the type of slurry, its concentration and size. Besides this the variation in speed also affects the performance as is observed in pumps with water. The maximum decrease in the head, with respect to clear water, at the operating point was found to be 47% for aggregate for size 20 mm, 15% concentration and 2600 rpm. The maximum decrement in efficiency at operating point for aggregate was found to be 47% for 4 mm size, 15% concentration and at 2200 rpm. The power increment requirement for aggregate was 9% for 4 mm size, 15% concentration and 2600 rpm.

  16. Vibration analysis of large centrifugal pump rotors

    Science.gov (United States)

    Y Zhao, W.; Ge, J. G.; Ma, D.; Li, C. M.; Bao, S. B.

    2013-12-01

    Through the critical speed of centrifugal pumps, internal flow field and the force of the impeller, we analyze centrifugal pump vibration. Using finite element analysis software ANSYS to calculate the natural frequency of the rotor system and the critical speed; with the help of the Fluent software to simulate pump internal flow field, we conclude that speed increase will not cause intense vibration of the fluid in the pump. Using unsteady numerical simulation we discovered that in an impeller suffering transient radial force cyclical change periodically, as well as the frequency size determined by the product of the impeller speed and number of blades, resonance phenomena should make impeller to transient radial force frequency. If wanting to avoid pump resonance when it is running away, the transient radial force frequency should avoid the frequency range which can cause resonance.

  17. Vibration analysis of large centrifugal pump rotors

    International Nuclear Information System (INIS)

    Through the critical speed of centrifugal pumps, internal flow field and the force of the impeller, we analyze centrifugal pump vibration. Using finite element analysis software ANSYS to calculate the natural frequency of the rotor system and the critical speed; with the help of the Fluent software to simulate pump internal flow field, we conclude that speed increase will not cause intense vibration of the fluid in the pump. Using unsteady numerical simulation we discovered that in an impeller suffering transient radial force cyclical change periodically, as well as the frequency size determined by the product of the impeller speed and number of blades, resonance phenomena should make impeller to transient radial force frequency. If wanting to avoid pump resonance when it is running away, the transient radial force frequency should avoid the frequency range which can cause resonance

  18. Centrifugal Force Based Magnetic Micro-Pump Driven by Rotating Magnetic Fields

    International Nuclear Information System (INIS)

    This paper presents a centrifugal force based magnetic micro-pump for the pumping of blood. Most blood pumps are driven by an electrical motor with wired control. To develop a wireless and battery-free blood pump, the proposed pump is controlled by external rotating magnetic fields with a synchronized impeller. Synchronization occurs because the rotor is divided into multi-stage impeller parts and NdFeB permanent magnet. Finally, liquid is discharged by the centrifugal force of multi-stage impeller. The proposed pump length is 30 mm long and 19 mm in diameter which much smaller than currently pumps; however, its pumping ability satisfies the requirement for a blood pump. The maximum pressure is 120 mmHg and the maximum flow rate is 5000ml/min at 100 Hz. The advantage of the proposed pump is that the general mechanical problems of a normal blood pump are eliminated by the proposed driving mechanism.

  19. Fault Detection and Isolation in Centrifugal Pumps

    DEFF Research Database (Denmark)

    Kallesøe, Carsten

    Centrifugal pumps are used in a variety of different applications, such as water supply, wastewater, and different industrial applications. Some pump installations are crucial for the applications to work. Failures can lead to substantial economic losses and can influence the life of many people...... when they occur. Therefore, detection of faults, if possible in an early stage, and isolation of their causes are of great interest. Especially fault detection, which can be used for predictive maintenance, can decrease working expenses and increase the reliability of the application in which the pump...... is placed. The topic of this work is Fault Detection and Identification in centrifugal pumps. Different approaches are developed with special focus on robustness. Robustness with respect to disturbances, unknown parts of the system, and parameter variations are considered. All developed algorithms...

  20. Centrifugal Pump Experiment for Chemical Engineering Undergraduates

    Science.gov (United States)

    Vanderslice, Nicholas; Oberto, Richard; Marrero, Thomas R.

    2012-01-01

    The purpose of this paper is to describe a Centrifugal Pump Experiment that provided an experiential learning experience to chemical engineering undergraduates at the University of Missouri in the spring of 2010 in the Unit Operations Laboratory course. Lab equipment was used by senior students with computer-based data and control technology. In…

  1. Design Optimization of Centrifugal Pump Using Radial Basis Function Metamodels

    OpenAIRE

    Yu Zhang; Jinglai Wu; Yunqing Zhang; Liping Chen

    2014-01-01

    Optimization design of centrifugal pump is a typical multiobjective optimization (MOO) problem. This paper presents an MOO design of centrifugal pump with five decision variables and three objective functions, and a set of centrifugal pumps with various impeller shroud shapes are studied by CFD numerical simulations. The important performance indexes for centrifugal pump such as head, efficiency, and required net positive suction head (NPSHr) are investigated, and the results indicate that th...

  2. Flow Analysis of the Cleveland Clinic Centrifugal Pump

    Science.gov (United States)

    Veres, Joseph P.; Golding, Leonard A. R.; Smith, William A.; Horvath, David; Medvedev, Alexander

    1997-01-01

    An implantable ventricular assist rotordynamic blood pump is being developed by the Cleveland Clinic Foundation in cooperation with the NASA Lewis Research Center. At the nominal design condition, the pump provides blood flow at the rate of 5 liters per minute at a pressure rise of 100 mm of mercury and a rotative speed of 3000 RPM. Bench testing of the centrifugal pump in a water/glycerin mixture has provided flow and pressure data at several rotative speeds. A one-dimensional empirical based pump flow analysis computer code developed at NASA Lewis Research Center has been used in the design process to simulate the flow in the primary centrifugal pump stage. The computer model was used to size key impeller and volute geometric parameters that influence pressure rise and flow. Input requirements to the computer model include a simple representation of the pump geometry. The model estimates the flow conditions at the design and at off-design operating conditions at the impeller leading and trailing edges and the volute inlet and exit. The output from the computer model is compared to flow and pressure data obtained from bench testing.

  3. Potential flow through centrifugal pumps and turbines

    Science.gov (United States)

    Sorensen, E

    1941-01-01

    The methods of conformal transformation up to the present have been applied to the potential flows in the rotation of solid bodies only to a limited extent. This report deals with aspects of centrifugal pumps and turbines such as: the complex potential for rotation, potential for the flow due to the blade rotation, velocities at the blade tip, comparison with "infinite number of blades," and a variable number of blades.

  4. Improvements to self priming centrifugal pumps

    International Nuclear Information System (INIS)

    This invention concerns a self priming centrifugal pump for dangerous liquids, high radioactive, flammable, explosive and very toxic liquids for instance, for which it is necessary to enclose the equipment in a biological protection cell, as is done in the nuclear industry (reprocessing of irradiated fuels). The device ensures that all the gases and radioactive and toxic aerosols present in the delivery pipe are returned through leak tight pipes into the drawing tank, the gaseous top of which is connected to a gas processing plant, without it being possible for them to escape from the plant and contaminate the cell or penetrate into an apparatus such as a filter under pressure that cannot work in their presence. The pump impeller cage is provided with horizontal partitions which define the pump body, a lower suction chamber, a middle delivery chamber and an upper venting chamber respectively connected to a suction pipe, a delivery pipe and a venting pipe connected to a gas processing unit significantly at atmospheric pressure. Leak tightness between these different chambers and the body of the pump is provided by three ring seals resting on the truncated part of the pump body as well as by an internal gasket fixed between the motor shaft and the upper wall of the venting chamber. As all the pipes are attached to the fixed pump body, the removable unit may be easily taken out or placed back simply by moving it vertically upwards

  5. Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump

    OpenAIRE

    Tao Li; Weiming Zhang; Ming Jiang; Zhengyang Li

    2013-01-01

    A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Re...

  6. Numerical Investigations on the Transient Performance of a Centrifugal Pump

    OpenAIRE

    Asim, Taimoor; Mishra, Rakesh

    2015-01-01

    Centrifugal pumps are an integral part of plants used in process industries. The flow structure within a centrifugal pump is very complex due to the interaction between the rotating impeller and the geometric features around it. In the present study, numerical investigations on a centrifugal pump have been carried out using a Computational Fluid Dynamics (CFD) based solver. This study employs finite volume technique in order to analyse the influence of variations in the rotational speed of th...

  7. Latex Micro-balloon Pumping in Centrifugal Microfluidic Platforms

    OpenAIRE

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Al-Faqheri, Wisam; Thio, Tzer Hwai Gilbert; Kazemzadeh, Amin; Wadi harun, Sulaiman; Madou, Marc

    2014-01-01

    Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-stepped processes on a single microfluidics disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force. In this paper, a novel micro-balloon pumping method that relies on elastic energy stored in a...

  8. Parametric representation of centrifugal pump homologous curves

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, Marcelo A.; Mattos, Joao R.L. de, E-mail: velosom@cdtn.br, E-mail: jrmattos@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)

  9. Rotordynamic Forces on Centrifugal Pump Impellers

    OpenAIRE

    Franz, R.; Arndt, N.; Caughey, T. K.; Brennen, C. E.; Acosta, A.J

    1987-01-01

    The asymmetric flow around an impeller in a volute exerts a force upon the impeller. To study the rotordynamic force on an impeller which is vibrating around its machine axis of rotation, the impeller, mounted on a dynamometer, is made to whirl in a circular orbit within the volute. The measured force is expressed as the sum of a steady radial force and an unsteady force due to the eccentric motion of the impeller. These forces were measured in separate tests on a centrifugal pump with rad...

  10. The CentriMag centrifugal blood pump as a benchmark for in vitro testing of hemocompatibility in implantable ventricular assist devices.

    Science.gov (United States)

    Chan, Chris H H; Pieper, Ina Laura; Hambly, Rebecca; Radley, Gemma; Jones, Alyssa; Friedmann, Yasmin; Hawkins, Karl M; Westaby, Stephen; Foster, Graham; Thornton, Catherine A

    2015-02-01

    Implantable ventricular assist devices (VADs) have proven efficient in advanced heart failure patients as a bridge-to-transplant or destination therapy. However, VAD usage often leads to infection, bleeding, and thrombosis, side effects attributable to the damage to blood cells and plasma proteins. Measuring hemolysis alone does not provide sufficient information to understand total blood damage, and research exploring the impact of currently available pumps on a wider range of blood cell types and plasma proteins such as von Willebrand factor (vWF) is required to further our understanding of safer pump design. The extracorporeal CentriMag (Thoratec Corporation, Pleasanton, CA, USA) has a hemolysis profile within published standards of normalized index of hemolysis levels of less than 0.01 g/100 L at 100 mm Hg but the effect on leukocytes, vWF multimers, and platelets is unknown. Here, the CentriMag was tested using bovine blood (n = 15) under constant hemodynamic conditions in comparison with a static control for total blood cell counts, hemolysis, leukocyte death, vWF multimers, microparticles, platelet activation, and apoptosis. The CentriMag decreased the levels of healthy leukocytes (P pump which could be used as a standard in blood damage assays to inform the design of new implantable blood pumps. PMID:25066768

  11. Rotary blood pump

    Science.gov (United States)

    Benkowski, Robert J. (Inventor); Kiris, Cetin (Inventor); Kwak, Dochan (Inventor); Rosenbaum, Bernard J. (Inventor); Bacak, James W. (Inventor); DeBakey, Michael E. (Inventor)

    1999-01-01

    A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein.

  12. Design Method for Single-Blade Centrifugal Pump Impeller

    Science.gov (United States)

    Nishi, Yasuyuki; Fujiwara, Ryota; Fukutomi, Junichiro

    The sewage pumps are demanded a high pump efficiency and a performance in passing foreign bodies. Therefore, the impeller used by these usages requires the large passed particle size (minimum particle size in the pump). However, because conventional design method of pump impeller results in small impeller exit width, it is difficult to be applied to the design of single-blade centrifugal pump impeller which is used as a sewage pump. This paper proposes a design method for single-blade centrifugal pump impeller. As a result, the head curve of the impeller designed by the proposed design method satisfied design specifications, and pump efficiency was over 62% more than conventional single-blade centrifugal pump impeller. By comparing design values with CFD analysis values, the suction velocity ratio of the design parameter agreed well with each other, but the relative velocity ratio did not agree due to the influence of the backflow of the impeller entrance.

  13. Prediction of performance of centrifugal pumps during starts under pressure

    Science.gov (United States)

    Rostafinski, W.

    1969-01-01

    Method which calculates start-up characteristics of centrifugal pumps reveals a capacity to predict pressure drop characteristics of pumps with vaned diffusers. Calculations are based on pump geometry, design-point flow, speed, and pressure rise, and the pump characteristic within range of approximately ten percent of the design-point flow.

  14. Stability of centrifugal pump characteristic curve

    OpenAIRE

    Chmatil, Ľuboš

    2011-01-01

    Předložená diplomová práce obsahuje teoretický rozbor charakteristik odstředíveho čerpadla, podmínky stability Y(Q) charakteristiky, výpočet charakteristiky ßč(ns), úpravy vedúce k stabilizaci spirálního telesa a oběžného kola, návrh spirály, obežného kola a následný výpočet v programe Fluent. This master's thesis includes theoretical analysis of characteristics of a centrifugal pump, conditions of stability of Y(Q) characteristic, calculation of characteristics ßč(ns), modifications leadi...

  15. Rotordynamic forces on centrifugal pump impellers

    Science.gov (United States)

    Franz, R.; Arndt, N.; Caughey, T. K.; Brennen, C. E.; Acosta, A. J.

    1987-01-01

    The asymmetric flow around an impeller in a volute exerts a force upon the impeller. To study the rotordynamic force on an impeller which is vibrating around its machine axis of rotation, the impeller, mounted on a dynamometer, is made to whirl in a circular orbit within the volute. The measured force is expressed as the sum of a steady radial force and an unsteady force due to the eccentric motion of the impeller. These forces were measured in separate tests on a centrifugal pump with radically increased shroud clearance, a two-dimensional impeller, and an impeller with an inducer, the impeller of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine). In each case, a destabilizing force was observed over a region of positive whirl.

  16. Whole blood pumping with a microthrottle pump

    OpenAIRE

    Davies, M J; Johnston, I. D.; Tan, C. K. L.; Tracey, M. C.

    2010-01-01

    We have previously reported that microthrottle pumps (MTPs) display the capacity to pump solid phase suspensions such as polystyrene beads which prove challenging to most microfluidic pumps. In this paper we report employing a linear microthrottle pump (LMTP) to pump whole, undiluted, anticoagulated, human venous blood at 200 μl min−1 with minimal erythrocyte lysis and no observed pump blockage. LMTPs are particularly well suited to particle suspension transport by virtue of their relatively ...

  17. Performance analysis of mini centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Wada, T.; Shinohara, H.

    2013-12-01

    Design method for a mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Then, a semi-open impeller for the mini centrifugal pump with 55mm impeller diameter is adopted in this research to take simplicity and maintenance into consideration. Splitter blades are adopted in this research to improve the performance and internal flow condition of mini centrifugal pump having large blade outlet angle. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on the performance and internal flow condition of the mini centrifugal pump. A three dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Flow condition at outlet of the rotor becomes uniform and back flow regions are suppressed in the case with the splitter blades. Further, the volute efficiency increases and the vortex loss decreases. In the present paper, the performance of the mini centrifugal pump is shown and the flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the performance analyses of the mini centrifugal pumps with and without the splitter blades are conducted.

  18. Design of a Bearingless Blood Pump

    Science.gov (United States)

    Barletta, Natale; Schoeb, Reto

    1996-01-01

    In the field of open heart surgery, centrifugal blood pumps have major advantages over roller pumps. The main drawbacks to centrifugal pumps are however problems with the bearings and with the sealing of the rotor shaft. In this paper we present a concept for a simple, compact and cost effective solution for a blood pump with a totally magnetically suspended impeller. It is based on the new technology of the 'Bearingless Motor' and is therefore called the 'Bearingless Blood Pump.' A single bearingless slice motor is at the same time a motor and a bearing system and is able to stabilize the six degrees of freedom of the pump impeller in a very simple way. Three degrees of freedom are stabilized actively (the rotation and the radial displacement of the motor slice). The axial and the angular displacement are stabilized passively. The pump itself (without the motor-stator and the control electronics) is built very simply. It consists of two parts only: the impeller with the integrated machine rotor and the housing. So the part which gets in contact with blood and has therefore to be disposable, is cheap. Fabricated in quantities, it will cost less than $10 and will therefore be affordable for the use in a heart-lung-machine.

  19. Numerical Calculation on Cavitation Pressure Pulsation in Centrifugal Pump

    OpenAIRE

    Weidong Shi; Chuan Wang; Wei Wang; Bing Pei

    2014-01-01

    In order to study the internal flow in centrifugal pump when cavitation occurs, numerical calculation of the unsteady flow field in the WP7 automobile centrifugal pump is conducted based on the Navier-Stokes equations with the RNG k-ε turbulence model and Zwart-Gerber-Belamri cavitation model. The distributions of bubble volume fraction and pressure pulsation laws in the pump are analyzed when cavitation occurs. The conclusions are as follows: the bubble volume fraction is larger on the sucti...

  20. 血液灌注量和破坏指标约束下的无叶片离心血泵结构优选方法的研究%Study on Optimal Selection of Structure of Vaneless Centrifugal Blood Pump with Constraints on Blood Perfusion and on Blood Damage Indexes

    Institute of Scientific and Technical Information of China (English)

    胡兆燕; 潘友联; 陈正龙; 张天逸; 路力军

    2012-01-01

    本文主要探索无叶片离心血泵的结构优选方法.根据临床使用要求确定优选目标;由无叶片离心血泵的结构特点制订优选方案集合;以灌注量和血液破坏程度为指标,经过两轮优选出最佳结构血泵.数值仿真结果表明可以满足设计要求,即体外循环对灌注量(压力0~380 mm Hg,流量0~8 L/min)、血液剪切破坏(叶轮表面剪切力不超过200 Pa)和撞击破坏的要求.该结构优选方法可以快速地在方案集合中确定最佳结构方案.%This paper is aimed to study the optimal selection of structure of vaneless centrifugal blood pump. The optimal objective is determined according to requirements of clinical use. Possible schemes are generally worked out based on structural feature of vaneless centrifugal blood pump. The optimal structure is selected from possible schemes with constraints on blood perfusion and blood damage indexes. Using an optimal selection method one can find the optimum structure scheme from possible schemes effectively. The results of numerical simulation of optimal blood pump showed that the method of constraints of blood perfusion and blood damage is competent for the requirements of selection of the optimal blood pumps.

  1. Investigation on complete characteristics and hydraulic transient of centrifugal pump

    International Nuclear Information System (INIS)

    An improved method was developed to obtain the complete characteristic of centrifugal pump. The conversion formula of complete characteristics is established based on the normal performance curve. An example was presented to illuminate the new method, and the complete characteristic curves of 14SA-10 centrifugal pump were obtained by the new method. The hydraulic transient of the centrifugal pump failure and start-up was simulated by method of characteristics (MOC), which quote the complete characteristics data. The results show that the inversion method is available to obtain the complete pump characteristic curves provided the normal performance curve. For hydraulic transient simulation, more accurate numerical result can be obtained, if the new model is adopted to convert the experimental normal performance curve to complete characteristics curve of centrifugal pump

  2. Investigation of Flow in a Centrifugal Pump

    Science.gov (United States)

    Fischer, Karl

    1946-01-01

    The investigation of the flow in a centrifugal pump indicated that the flow patterns in frictional fluid are fundamentally different from those in frictionless fluid. In particular, the dead air space adhering to the section side undoubtedly causes a reduction of the theoretically possible delivery head. The velocity distribution over a parallel circle is also subjected to a noticeable change as a result of the incomplete filling of the passages. The relative velocity on the pressure side of the vane, which for passages completely filled with active flow would differ little from zero even at comparatively lower than normal delivery volume, is increased, so that no rapid reverse flow occurs on the pressure side of the vane even for smaller delivery volume. It was established, further, that the flow ceases to be stationary for very small quantities of water. The inflow to the impeller can be regarded as radial for the operating range an question. The velocity triangles at the exit are subjected to a significant alteration in shape ae a result of the increased peripheral velocity, which may be of particular importance in the determination of the guide vane entrance angle.

  3. BIOMATERIALS FOR ROTARY BLOOD PUMPS

    NARCIS (Netherlands)

    VANOEVEREN, W

    1995-01-01

    Rotary blood pumps are used for cardiac assist and cardiopulmonary support since mechanical blood damage is less than with conventional roller pumps. The high shear rate in the rotary pump and the reduced anticoagulation of the patient during prolonged pumping enforces high demands on the biocompati

  4. Blood Pump Bearing System

    Science.gov (United States)

    Aber, Gregory S. (Inventor)

    2000-01-01

    An apparatus is provided for a blood pump bearing system within a pump housing to support long-term highspeed rotation of a rotor with an impeller blade having a plurality of individual magnets disposed thereon to provide a small radial air gap between the magnets and a stator of less than 0.025 inches. The bearing system may be mounted within a flow straightener, diffuser, or other pump element to support the shaft of a pump rotor. The bearing system includes a zirconia shaft having a radiused end. The radiused end has a first radius selected to be about three times greater than the radius of the zirconia shaft. The radiused end of the zirconia shaft engages a flat sapphire endstone. Due to the relative hardness of these materials a flat is quickly produced during break-in on the zirconia radiused end of precisely the size necessary to support thrust loads whereupon wear substantially ceases. Due to the selection of the first radius, the change in shaft end-play during pump break-in is limited to a total desired end-play of less than about 0.010 inches. Radial loads are supported by an olive hole ring jewel that makes near line contact around the circumference of the Ir shaft to support big speed rotation with little friction. The width of olive hole ring jewel is small to allow heat to conduct through to thereby prevent heat build-up in the bearing. A void defined by the bearing elements may fill with blood that then coagulates within the void. The coagulated blood is then conformed to the shape of the bearing surfaces.

  5. Effect of pumping chamber on performance of non-overload centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    谷云庆; 吴登昊; 牟介刚; 蒋兰芳; 代东顺; 施瀚昱; 郑水华

    2015-01-01

    In order to specify the characteristics of un-overloaded centrifugal pumps, the IH100-65-200 pump was chosen as the model pump. Different calculation models for centrifugal pumps were established under different pumping chamber sectional parameters. In the numerical simulation of the centrifugal pumps flow field, the shaft power, head, efficiency, and the changes of the internal flow field under different sectional areas and sectional shapes were studied with the RNGk−εturbulence model, and the influence of the pumping chamber section characteristics of the non-overloaded centrifugal pumps were analyzed. The results show that sectional areas have a significant impact on the non-overload characteristics of centrifugal pumps. The shaft power and head of centrifugal pump are increasing with a lager sectional area, by which the gradient of head curves decreases. The efficiency is improved under a large flow rate condition, but the head and the efficiency are reduced at a small flow rate. It is also observed that the sectional shapes have less influence on the shaft power, the hydraulic performance and flow field characteristics of a centrifugal pump.

  6. Experimental Study on Series Operation of Sliding Vane Pump and Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Tao Li

    2013-01-01

    Full Text Available A platform for sliding vane pump and centrifugal pump tests is installed to study the series operation of them under different characteristics of pipeline. Firstly, the sliding vane pump and the centrifugal pump work independently, and the performance is recorded. Then, the two types of pumps are combined together, with the sliding vane pump acting as the feeding pump. Comparison is made between the performance of the independently working pump and the performance of series operation pump. Results show that the system flow rate is determined by the sliding vane pump. In order to ensure the stability of the series operation pumping system, the energy consumption required by the pipeline under the system flow should be greater than the pressure energy centrifugal pump can generate. Otherwise, the centrifugal pump can not operate stably, with reflux, swirl, gas-liquid two-phase flow in the runner and strong vibration and noise. The sliding vane pump can be in serial operation with the centrifugal pump under limited conditions.

  7. Centrifugal pumping of gas-liquid mixtures: a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Estevam, Valdir [PETROBRAS, Rio de Janeiro, RJ (Brazil); Franca, Fernando A. [Universidade Estadual de Campinas, SP (Brazil); Alhanati, Francisco J.S. [C-Fer Technologies, Edmonton, Alberta (Canada)

    2004-07-01

    Centrifugal pumps are known to show a 'surging' behavior at certain conditions of free gas and liquid flow rate at the intake. In the 'surging region' on a pump characteristic curve, the head generated is significantly lower than if the pump were handling a gas-liquid homogeneous mixture. The surging happens, as one shows in this paper, due to the existence of a gas pocket, referred as 'elongated bubble', at the pump impeller inlet region. Therefore, to be able to predict the performance of centrifugal pumps under two-phase conditions, one has to disclose and model the mechanisms that set existence of the elongated bubble at the impeller inlet, besides calculating its length inside the impeller. This paper reports on the results of experimental and mechanistic modelling work conducted with the objective of better predicting the gas-liquid performance of centrifugal pumps under all range of conditions, including those characterized by 'surging'. The focus was on small diameter centrifugal pumps used to produce oil wells. A mechanistic two-fluid model devised to calculate the head generated by the pump was developed. The predictions of the model show good agreement with data collected for this study, and with data recently collected by other research organizations. (author)

  8. Model Based Fault Detection in a Centrifugal Pump Application

    DEFF Research Database (Denmark)

    Kallesøe, Carsten; Cocquempot, Vincent; Izadi-Zamanabadi, Roozbeh

    2006-01-01

    A model based approach for fault detection in a centrifugal pump, driven by an induction motor, is proposed in this paper. The fault detection algorithm is derived using a combination of structural analysis, observer design and Analytical Redundancy Relation (ARR) design. Structural considerations...... the algorithm is capable of detecting four different faults in the mechanical and hydraulic parts of the pump....

  9. Hemocompatibility of Axial Versus Centrifugal Pump Technology in Mechanical Circulatory Support Devices.

    Science.gov (United States)

    Schibilsky, David; Lenglinger, Matthias; Avci-Adali, Meltem; Haller, Christoph; Walker, Tobias; Wendel, Hans Peter; Schlensak, Christian

    2015-08-01

    The hemocompatible properties of rotary blood pumps commonly used in mechanical circulatory support (MCS) are widely unknown regarding specific biocompatibility profiles of different pump technologies. Therefore, we analyzed the hemocompatibility indicating markers of an axial flow and a magnetically levitated centrifugal device within an in vitro mock loop. The HeartMate II (HM II; n = 3) device and a CentriMag (CM; n = 3) adult pump were investigated in a human whole blood mock loop for 360 min using the MCS devices as a driving component. Blood samples were analyzed by enzyme-linked immunosorbent assay for markers of coagulation, complement system, and inflammatory response. There was a time-dependent activation of the coagulation (thrombin-antithrombin complexes [TAT]), complement (SC5b-9), and inflammation system (polymorphonuclear [PMN] elastase) in both groups. The mean value of TAT (CM: 4.0 μg/L vs. 29.4 μg/L, P centrifugal CM device showed significantly lower activation of coagulation and inflammation than that of the HM II axial flow pump. Both HM II and CM have demonstrated an acceptable hemocompatibility profile in patients. However, there is a great opportunity to gain a clinical benefit by developing techniques to lower the blood surface interaction within both pump technologies and a magnetically levitated centrifugal pump design might be superior. PMID:26234452

  10. Parametric performance evaluation of a hydraulic centrifugal pump

    International Nuclear Information System (INIS)

    Parametric study of a hydraulic centrifugal pump with backward curved blades has been performed numerically using three-dimensional Reynolds-averaged Navier-Stokes equations. The shear stress transport turbulence model was used for analysis of turbulence. The finite volume method and an unstructured grid system were used for the numerical solution. The optimal grid system in the computational domain was selected through a grid dependency test. Tested parameters were related to the geometry of the impeller and volute: seven variables defining the hub and shroud contours and the blades angle of impeller, and two variables defining the inlet width and expansion angle of volute. The effects of these parameters on the hydrodynamic performance of the centrifugal pump have been investigated. It was found that the centrifugal water pump with the twisted blades has the enhancing efficiency compared to the straight blades pump

  11. Parametric performance evaluation of a hydraulic centrifugal pump

    Science.gov (United States)

    Heo, M. W.; Y Kim, K.; Ma, S. B.; Yoo, I. S.; Choi, W. C.; Kim, J. H.; Choi, Y. S.

    2014-03-01

    Parametric study of a hydraulic centrifugal pump with backward curved blades has been performed numerically using three-dimensional Reynolds-averaged Navier-Stokes equations. The shear stress transport turbulence model was used for analysis of turbulence. The finite volume method and an unstructured grid system were used for the numerical solution. The optimal grid system in the computational domain was selected through a grid dependency test. Tested parameters were related to the geometry of the impeller and volute: seven variables defining the hub and shroud contours and the blades angle of impeller, and two variables defining the inlet width and expansion angle of volute. The effects of these parameters on the hydrodynamic performance of the centrifugal pump have been investigated. It was found that the centrifugal water pump with the twisted blades has the enhancing efficiency compared to the straight blades pump.

  12. Damages on pumps and systems the handbook for the operation of centrifugal pumps

    CERN Document Server

    Merkle, Thomas

    2014-01-01

    Damage on Pumps and Systems. The Handbook for the Operation of Centrifugal Pumps offers a combination of the theoretical basics and practical experience for the operation of circulation pumps in the engineering industry. Centrifugal pumps and systems are extremely vulnerable to damage from a variety of causes, but the resulting breakdown can be prevented by ensuring that these pumps and systems are operated properly. This book provides a total overview of operating centrifugal pumps, including condition monitoring, preventive maintenance, life cycle costs, energy savings and economic aspects. Extra emphasis is given to the potential damage to these pumps and systems, and what can be done to prevent breakdown. Addresses specific issues about pumping of metal chips, sand, abrasive dust and other solids in fluidsEmphasis on economic and efficiency aspects of predictive maintenance and condition monitoring Uses life cycle costs (LCC) to evaluate and calculate the costs of pumping systems

  13. A REVIEW PAPER ON DEVELOPMENT OF IMPELLER OF CENTRIFUGAL PUMP USING COMPUTATIONAL FLUID DYNAMICS

    OpenAIRE

    Mr. Nilesh Nemgonda Patil

    2015-01-01

    Nowadays, the centrifugal pumps became very popular because of recent development of high speed electric motors, steam turbines etc.Centrifugal pumps can be single-stage or may be multistage pumps. It depends upon the number of impellers used in the pump. Single stage pump consists of only one impeller while in multistage pumps the impellers are mounted in the series in pumps. These Centrifugal pumps can be analyzed by software code like Computational Fluid Dynamics (CFD).This CFD...

  14. A centrifugal pump concept designed for multiple use in space

    Science.gov (United States)

    Wunderlich, E.; Wulz, H. G.

    A centrifugal pump concept was elaborated for a multiple application in future spacecrafts. Based on this concept a prototype of a small centrifugal pump was manufactured and comprehensively tested. The model pump has been approved in different test series with the fluids liquid ammonia and demineralized water. The design of the model pump was driven by strict requirements of COLUMBUS, namely long life, noiseless operation, minimum mass and low energy consumption. Because of its modular design and as a result of selected materials of multiple compatibility, this pump is suited for the delivery of various further fluids, such as freons, hydrocarbons, propellants (hydrazine) etc.. It is also capable of pumping corrosive or toxic fluids for laboratory processes in space. The wide speed range from about 1,00 to 20,000 rpm which corresponds to a flow from about 1 to 20 l/min, permits an energy saving adaption and flow control.

  15. Fault Diagnosis in a Centrifugal Pump Using Active Magnetic Bearings

    OpenAIRE

    Nordmann Rainer; Aenis Martin

    2004-01-01

    The number of rotors running in active magnetic bearings (AMBs) has increased over the last few years. These systems offer a great variety of advantages compared to conventional systems. The aim of this article is to use the AMBs together with a developed built-in software for identification, fault detection, and diagnosis in a centrifugal pump. A single-stage pump representing the turbomachines is investigated. During full operation of the pump, the AMBs are used as actuators to generate def...

  16. [Temporary use of centrifugal pump for pump thrombosis in patients with paracorporeal ventricular assist device].

    Science.gov (United States)

    Kimura, Mitsutoshi; Kinoshita, Osamu; Nawata, Kan; Yamauchi, Haruo; Itoda, Yoshifumi; Hoshino, Yasuhiro; Kashiwa, Koichi; Kubo, Hitoshi; Kurosawa, Hideo; Takahashi, Mai; Koga, Sayaka; Ono, Minoru

    2015-05-01

    Nipro paracorporeal ventricular assist device( VAD) is often associated with pump thrombosis which causes severe complications such as brain infarction, often requiring pump change. However, Nipro VAD pump is an expensive device and it is difficult to change pumps frequently at a short interval. We have temporarily used Rotaflow centrifugal pump for recurrent pump thrombosis in patients with Nipro VADs. From January 2012 through December 2013, 19 patients underwent Nipro VADs implantation at our institution, and 9 of them underwent pump change from Nipro pumps to Rotaflow centrifugal pumps. A total of 25 Rotaflow centrifugal pumps were used in these 9 patients, with the total circulatory support duration of 526 days. The median support period was 15 days (range;2-128 days). There were 2 cerebrovascular accidents and 1 Rotaflow pump circuit thrombosis during this period. Change from Rotaflow to Nipro VAD pump resulted in decrease in hematocrit by about 3 point. There was no difference in liver or renal function between before and after the pump change. Our results suggest that temporary use of Rotaflow centrifugal pump for recurrent pump thrombosis in patients with Nipro VADs may be a promising alternative. PMID:25963778

  17. Effect of centrifugal pump impeller shapes on cavitation erosion

    International Nuclear Information System (INIS)

    The cavitation erosion test and suction performance test for five types of centrifugal pump impellers with different blade inlet angles and different position of blade inlet edges are carried out by using the open-type pump test loop and painting method. The relationship among the shape of impellers, flow rate, pump running time and position, degree of cavitation erosion inside impellers are made clear under the state of 3% pump head dropping. The experimental results are discussed with the internal flow pattern and inlet reverse flow occurred in the pump

  18. Fault diagnosis of monoblock centrifugal pump using SVM

    Directory of Open Access Journals (Sweden)

    V. Muralidharan

    2014-09-01

    Full Text Available Monoblock centrifugal pumps are employed in variety of critical engineering applications. Continuous monitoring of such machine component becomes essential in order to reduce the unnecessary break downs. At the outset, vibration based approaches are widely used to carry out the condition monitoring tasks. Particularly fuzzy logic, support vector machine (SVM and artificial neural networks were employed for continuous monitoring and fault diagnosis. In the present study, the application of SVM algorithm in the field of fault diagnosis and condition monitoring is discussed. The continuous wavelet transforms were calculated for different families and at different levels. The computed transformation coefficients form the feature set for the classification of good and faulty conditions of the components of centrifugal pump. The classification accuracies of different continuous wavelet families at different levels were calculated and compared to find the best wavelet for the fault diagnosis of the monoblock centrifugal pump.

  19. Small centrifugal pumps for low thrust rockets

    Science.gov (United States)

    Gulbrandsen, N. C.; Furst, R. B.; Burgess, R. M.; Scheer, D. D.

    1985-01-01

    This paper presents the results of a combined analytical and experimental investigation of low specific speed pumps for potential use as components of propellant feed systems for low thrust rocket engines. Shrouded impellers and open face impellers were tested in volute type and vaned diffuser type pumps. Full- and partial-emission diffusers and full- and partial-admission impellers were tested. Axial and radial loads, head and efficiency versus flow, and cavitation tests were conducted. Predicted performance of two pumps are compared when pumping water and liquid hydrogen. Detailed pressure loss and parasitic power values are presented for two pump configurations. Partial-emission diffusers were found to permit use of larger impeller and diffuser passages with a minimal performance penalty. Normal manufacturing tolerances were found to result in substantial power requirement variation with only a small pressure rise change. Impeller wear ring leakage was found to reduce pump pressure rise to an increasing degree as the pump flowrate was decreased.

  20. The effect of gas fraction on centrifugal pump

    Science.gov (United States)

    Zhu, Z. T.; Wang, Y.; Zhao, L. F.; Ning, C.; Xie, S. F.; Liu, Z. C.

    2015-01-01

    In order to study the multiphase flow field in M125 centrifugal pump, three-dimensional modeling was used for internal flow through three-dimensional software Pro/E. Then based on SST turbulence model combining with Rayleigh-Plesset cavitation model, and structured grid to simulate the hydraulic characteristics of volute and impeller within different gas conditions. The velocity, pressure and gas volume fraction distributions of the interior flow field of volute and impeller were obtained and analyzed, which revealed the effect of gas fractions on the flow characteristic of the centrifugal pump.

  1. Flow in a Low Specific Speed Centrifugal Pump Using PIV

    OpenAIRE

    Cui Dai; Liang Dong

    2013-01-01

    The interflow plays important roles in centrifugal pump design. In order to study the effect of rotation and z-axis on internal flow, two-dimensional particle image velocimetry (PIV) measurements have been performed to measure the steady velocity field on three planes in all impeller passages of a low specific-speed centrifugal pump. The results show that the relative velocity flows in blade passages are obviously different in terms of the positions of the blade relative to the tongue. The in...

  2. Characterization of a centrifugal pump in He II

    Science.gov (United States)

    Weisend, J. G., II; Van Sciver, S. W.

    1988-01-01

    As part of an effort to determine the feasibility of helium transfer in space, a centrifugal pump was tested in He II at a variety of flow rates, pump speeds, and fluid temperatures. The pump, which has a straight bladed impeller 6.86 cm in diameter, generated a maximum pressure rise of 15 kPa and a maximum flow rate of 22 g/s for the conditions of the test. Pump performance seems to be independent of fluid temperature and is in good agreement with the values predicted by the manufacturer. Over the range of flow coefficients, the measured maximum efficiency is around 50 percent. Cavitation is observed in the pump and is thought to be highly dependent on the local heating of the helium in the pump. Preliminary measurements of the noise spectra of the pump suggest a possible mechanism to predict the onset of cavitation.

  3. Computer-aided design and optimization of centrifugal pumps

    Energy Technology Data Exchange (ETDEWEB)

    Asuaje, M.; Bakir, F.; Kouidri, S.; Noguera, R.; Rey, R.

    2005-03-15

    Improvement in computer power and the development of numerical computational methods over the last few years have allowed the emergence of computational fluid dynamic (CFD) codes, making possible the numerical simulation of flow and energy transfer in turbo machines. To improve the efficiency of these tools, fast design software must be used. Within the framework of the optimization process of centrifugal pumps, HELIOX software was developed. It is a tool for design and performance analysis of centrifugal pumps. HELIOX allows quick design of new pumps and improvement of existing ones. HELIOX's performance analysis has been validated through many industrial cases: approximately 100 machines of different sizes and mechanical power. Heliox can be linked to quasi-and three-dimensional analysis tools; these tools enable a better understanding of physical phenomena so as to control the flow fields inside pumps. (Author)

  4. Axial and centrifugal pump meanline performance analysis

    Science.gov (United States)

    Veres, Joseph P.

    1994-01-01

    A meanline pump flow modeling method has been developed to provide a fast capability for modeling pumps of cryogenic rocket engines. Based on this method, a meanline pump flow code (PUMPA) has been written that can predict the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The design point rotor efficiency is obtained from empirically derived correlations of loss to rotor specific speed. The rapid input setup and computer run time for the meanline pump flow code makes it an effective analysis and conceptual design tool. The map generation capabilities of the PUMPA code provide the information needed for interfacing with a rocket engine system modeling code.

  5. Measurements of the rotordynamic shroud forces for centrifugal pumps

    Science.gov (United States)

    Guinzburg, A.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1990-01-01

    An experiment was designed to measure the rotordynamic shroud forces on a centrifugal pump impeller. The measurements were done for various whirl/impeller speed ratios and for different flow rates. A destabilizing tangential force was measured for small positive whirl ratios and this force decreased with increasing flow rate.

  6. Small, submersible, centrifugal pump for liquid nitrogen

    DEFF Research Database (Denmark)

    Rustad, B.M.; Nielsen, A.; Passell, L.

    1965-01-01

    Full details are given of a pump designed to circulate several liters/min. It can be evacuated before use to exclude oxygen and may be used at pressures of several atmospheres.......Full details are given of a pump designed to circulate several liters/min. It can be evacuated before use to exclude oxygen and may be used at pressures of several atmospheres....

  7. Improvement of Pump Performance and Suppression of Cavitation in a Centrifugal Pump by J-Groove

    OpenAIRE

    Young-Do, Choi; Kurokawa, Junichi; Shiraki, Satoshi; Kimura, Tomonori; Nagahara, Takahide

    2006-01-01

    The purpose of the present study is not only to develop a simple method to improve pump performance but also to suppress the occurrence of cavitation in the centrifugal pump by use of J-Groove. J-Groove is a shallow groove installed on the casing wall in the meridional direction. The application of J-Groove to a centrifugal pump with a new type impeller of "semi-closed impeller" has proved its effectiveness as a useful countermeasure of the unstable pump performance and cavitation. The result...

  8. Impeller inlet geometry effect on performance improvement for centrifugal pumps

    International Nuclear Information System (INIS)

    This research treats the effect of impeller inlet geometry on performance improvement for a boiler feed pump, who is a centrifugal pump having specific speed of 183 m.m3min-1.min-1 and close type impeller with exit diameter of 450 mm. The hydraulic performance and cavitation performance of the pump have been tested experimentally. In order to improve the pump, five impellers have been considered by extending the blade leading edge or applying much larger blade angle at impeller inlet compared with the original impeller. The 3-D turbulent flow inside those pumps has been analyzed basing on RNG k-ε turbulence model and VOF cavitation model. It is noted that the numerical results are fairly good compared with the experiments. Based on the experimental test and numerical simulation, the following conclusions can be drawn: (1) Impeller inlet geometry has important influence on performance improvement in the case of centrifugal pump. Favorite effects on performance improvement have been achieved by both extending the blade leading edge and applying much larger blade angle at impeller inlet: (2) It is suspected that the extended leading edge have favorite effect for improving hydraulic performance, and the much larger blade angle at impeller inlet have favorite effect for improving cavitation performance for the test pump: (3) Uniform flow upstream of impeller inlet is helpful for improving cavitation performance of the pump

  9. A small centrifugal pump for circulating cryogenic helium

    International Nuclear Information System (INIS)

    A small centrifugal pump is described which has been developed to circulate supercritical helium through a test loop for superconducting magnets. The pump has a fully enclosed warm and which contains the adjustable speed brushless DC drive motor and self-acting bearings operating in helium gas. The drive and bearing system is designed to minimize contaimination to the circulating supercritical helium in the test loop. The performance data which have been obtained show that the pump operates very close to its design specifications. Additional tests are planned to provide a more complete range of performance data for the pump. Subsequent record discussion concerned the pump shaft and the efficiency of the heat leak to the heat station. Efficiency of at least 65% is attainable with this pump, including all heat leak

  10. Experiment of a centrifugal pump during changing speed operation

    International Nuclear Information System (INIS)

    In this paper, a method of changing rotational speed of impeller periodically as the pulsatile working condition is developed to realize pulse outputs both of flow discharge and of head for a centrifugal pump through experiment. The performance of the centrifugal pump under pulsatile working operation condition is measured which indicates this model pump could produce desired pulse flow under such condition. Flow patterns at four testing points under pulsatile conditions are obtained by means of the particle image velocimetry (PIV) technology both with laser induced fluorescence (LIF) particles and refractive index matched (RIM) fluid. Results of PIV measurement show the distributions of velocity, streamlines, and the principal Reynolds normal stress (PRNS). Under the design flow rate condition, the relative velocity in the blade channel distributes smoothly and decreases from inlet to exit. And at the impeller exit, the relative velocity is lower close to suction side than that near pressure side of blade in most of blade channels.

  11. Experiment of a centrifugal pump during changing speed operation

    Science.gov (United States)

    Yuan, H. J.; Shao, J.; Wu, Y. L.; Liu, S. H.

    2012-11-01

    In this paper, a method of changing rotational speed of impeller periodically as the pulsatile working condition is developed to realize pulse outputs both of flow discharge and of head for a centrifugal pump through experiment. The performance of the centrifugal pump under pulsatile working operation condition is measured which indicates this model pump could produce desired pulse flow under such condition. Flow patterns at four testing points under pulsatile conditions are obtained by means of the particle image velocimetry (PIV) technology both with laser induced fluorescence (LIF) particles and refractive index matched (RIM) fluid. Results of PIV measurement show the distributions of velocity, streamlines, and the principal Reynolds normal stress (PRNS). Under the design flow rate condition, the relative velocity in the blade channel distributes smoothly and decreases from inlet to exit. And at the impeller exit, the relative velocity is lower close to suction side than that near pressure side of blade in most of blade channels.

  12. Numerical investigation of suction vortices behavior in centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    An, Young Joon; Shin, Byeong Rog [Changwon National University, Changwon (Korea, Republic of)

    2011-03-15

    A numerical simulation on suction vortices behavior in a centrifugal pump was carried out to investigate their influence on the internal flow through impellers including formation and shedding of cavitation by using a finite-volume method and k-{omega} Shear Stress Transport turbulence model. For cavitating flow, a two phase homogeneous cavitation model was used. A full three-dimensional flow in a single section centrifugal pump consisting of a six blade impeller and shroud ring was computed with structured mesh. A constant suction vortex is imposed as a boundary condition. Vortices behavior was investigated according to the variation of flow rates of two pump systems with and without suction vortices. From the results, suction vortices induced biased flow structure and more cavitations, especially at the low flow rate condition. Complicated internal flow phenomena through impellers such as formation of cavitations, growing and shedding of the vortex, flow separation and flow unsteadiness due to the suction vortices are investigated and discussed.

  13. Numerical investigation of suction vortices behavior in centrifugal pump

    International Nuclear Information System (INIS)

    A numerical simulation on suction vortices behavior in a centrifugal pump was carried out to investigate their influence on the internal flow through impellers including formation and shedding of cavitation by using a finite-volume method and k-ω Shear Stress Transport turbulence model. For cavitating flow, a two phase homogeneous cavitation model was used. A full three-dimensional flow in a single section centrifugal pump consisting of a six blade impeller and shroud ring was computed with structured mesh. A constant suction vortex is imposed as a boundary condition. Vortices behavior was investigated according to the variation of flow rates of two pump systems with and without suction vortices. From the results, suction vortices induced biased flow structure and more cavitations, especially at the low flow rate condition. Complicated internal flow phenomena through impellers such as formation of cavitations, growing and shedding of the vortex, flow separation and flow unsteadiness due to the suction vortices are investigated and discussed

  14. Optimization of centrifugal pump cavitation performance based on CFD

    Science.gov (United States)

    Xie, S. F.; Wang, Y.; Liu, Z. C.; Zhu, Z. T.; Ning, C.; Zhao, L. F.

    2015-01-01

    In order to further improve the cavitation performance of a centrifugal pump, slots on impeller blade near inlet were studied and six groups of hydraulic model were designed. Base on cavitating flow feature inside a centrifugal pump, bubble growth and implosion are calculated from the Rayleigh-Plesset equation which describes the dynamic behavior of spherical bubble and RNG κ-epsilon model was employed to simulate and analyze the internal two-phase flow of the model pump under the same conditions. The simulation results show that slots on blade near inlet could improve the cavitation performance and cavitation performance improvement of the second group was more obvious. Under the same conditions, the pressure on the back of blade near inlet was higher than the pressure on the back of unmodified blade near inlet, and energy distribution in the flow channel between the two blades was more uniform with a small change of head.

  15. 应用多相流技术探究离心式血泵的性能%Research on the Performance of the Centrifugal Blood Pump by Using the Multi-Phase Flow Analysis Technique

    Institute of Scientific and Technical Information of China (English)

    刘晓军; 杨俊培; 黄碧娟; 刘莉

    2015-01-01

    Objective To explore the impacts of different structures on the performance of blood pump by using the CFD multi-phase lfow analysis technique.Methods The centrifugal blood pumps with two different structures were designed and introduced with Interface. Then under the same working condition, the multi-phase lfow simulation on the pumps were conducted. The hydraulic performance and hemolytic properties of the blood pump were analyzed by examining the distribution of the lfow ifeld velocity vector and the shear stress cloud.Results Under the condition thatQ=6.24 L/min, and the supply pressure 100 mmHg, the rotational speed of the blood pump with XZ structure was 1950 rpm, lower than that speed (2082 rpm) with L structure. The lfow inside the two structures worked well. However, the highest speed inside L was 6.33 m/s, higher than that speed of XZ (5.44 m/s). The area with its shear stress larger than 150 Pa covered respectively 0.0022% and 0.206% respectively in XZ structure and L structure.Conclusion The pump with XZ structure showed better hydraulic performance and hemolytic properties. But the simple arc streamlined blades required for further improvements in deceleration and decompression.%目的:应用计算流体动力学多相流分析技术,探究不同结构对血泵性能的影响。方法设计2种不同结构的离心式血泵,引入CED软件中的Interface概念,相同工况下,进行多相流模拟,通过流场的速度矢量分布、剪切应力云图等分析血泵的水力性能和溶血性能。结果流量Q=6.24 L/min,供压100 mmHg工况下,12只斜直叶片(XZ)结构的血泵转速为1950 rpm<8只流线型叶片(L)结构的2082 rpm。2种结构内部流场流动情况良好,结构L内部最大速度6.33 m/s>XZ结构的5.44 m/s。XZ和L结构剪切应力>150 Pa的区域分别为0.0022%和0.2060%。结论 XZ结构的血泵在水力性能和溶血性能上均有较好的表现,简单圆弧流线型叶片在降速

  16. Cavitating flow investigation inside centrifugal impellers for a condensate pump

    International Nuclear Information System (INIS)

    In order to investigate the effect of blade inlet angle on centrifugal pump cavitation performance, numerical simulation of cavitating turbulent flow is conducted for a condensate pump with different impellers based on SST k−ω turbulence model and a mixture cavitation model. The results indicate that for a condensate pump having meridional section with larger area at blade leading edge compared with conventional pumps, the reverse flows inside the blade-to-blade channels are not negligible. It is noted that large incidence at blade leading edge is helpful to improve the cavitation performance for the pump. The possible reason may be the growth of cavities inside the impeller has less influence on the flow in the channel between two neighboring blades. Further, uniform incidence angle along the blade leading edge is preferable for the improvement of cavitation performance.

  17. Diagnosis of Centrifugal Pump Faults Using Vibration Methods

    International Nuclear Information System (INIS)

    Pumps are the largest single consumer of power in industry. This means that faulty pumps cause a high rate of energy loss with associated performance degradation, high vibration levels and significant noise radiation. This paper investigates the correlations between pump performance parameters including head, flow rate and energy consumption and surface vibration for the purpose of both pump condition monitoring and performance assessment. Using an in-house pump system, a number of experiments have been carried out on a centrifugal pump system using five impellers: one in good condition and four others with different defects, and at different flow rates for the comparison purposes. The results have shown that each defective impeller performance curve (showing flow, head, efficiency and NPSH (Net Positive Suction Head) is different from the benchmark curve showing the performance of the impeller in good condition. The exterior vibration responses were investigated to extract several key features to represent the healthy pump condition, pump operating condition and pump energy consumption. In combination, these parameter allow an optimal decision for pump overhaul to be made.

  18. Rotating and positive-displacement pumps for low-thrust rocket engines. Volume 1: Pump Evaluation and design. [of centrifugal pumps

    Science.gov (United States)

    Macgregor, C.; Csomor, A.

    1974-01-01

    Rotating and positive displacement pumps of various types were studied for pumping liquid fluorine for low-thrust, high-performance rocket engines. Included in the analysis were: centrifugal, pitot, Barske, Tesla, drag, gear, vane, axial piston, radial piston, diaphragm, and helirotor pump concepts. The centrifugal pump and the gear pump were selected and these were carried through detailed design and fabrication. Mechanical difficulties were encountered with the gear pump during the preliminary tests in Freon-12. Further testing and development was therefore limited to the centrifugal pump. Tests on the centrifugal pump were conducted in Freon-12 to determine the hydrodynamic performance and in liquid fluorine to demonstrate chemical compatibility.

  19. Origins of hydrodynamic forces on centrifugal pump impellers

    OpenAIRE

    Adkins, Douglas R.; Brennen, Christopher E.

    1986-01-01

    Hydrodynamic interactions that occur between a centrifugal pump impeller and volute are experimentally and theoretically investigated. The theoretical analysis considers the inability of the blades to perfectly guide the flow through the impeller, and also includes a quasi-one dimensional treatment of the flow in the volute. The disturbance at the impeller discharge and the resulting forces are determined by the theoretical model. The model is then extended to obtain the hydrodynamic force pe...

  20. Analyses of Hydrodynamic Radial Forces on Centrifugal Pump Impellers

    OpenAIRE

    Adkins, D. R.; Brennen, C. E.

    1988-01-01

    Hydrodynamic interactions that occur between a centrifugal pump impeller and a volute are experimentally and theoretically investigates. The theoretical analysis considers the inability of the blades to perfectly guide the flow through the impeller, and also includes a quasi-one dimensional treatment of flow in the volute. Flow disturbances at the impeller discharge and the resulting forces are determined by the theoretical model. The model is then extended to obtain the hydrodynamic force...

  1. Influence of blade angle distribution along leading edge on cavitation performance of a centrifugal pump

    Science.gov (United States)

    Xu, Y.; Tan, L.; Cao, S. L.; Wang, Y. C.; Meng, G.; Qu, W. S.

    2015-01-01

    The influence of blade angle distribution along leading edge on cavitation performance of centrifugal pumps is analysed in the present paper. Three sets of blade angle distribution along leading edge for three blade inlet angles are chosen to design nine centrifugal pump impellers. The RNG k-epsilon turbulence model and the Zwart-Gerber-Belamri cavitation model are employed to simulate the cavitation flows in centrifugal pumps with different impellers and the same volute. The numerical results are compared with the experimental data, and the comparison proves that the numerical simulation can accurately predict the cavitation performance of centrifugal pumps. On the basis of the numerical simulations, the pump head variations with pump inlet pressure, and the flow details in centrifugal pump are revealed to demonstrate the influence of blade angle distribution along leading edge on cavitation performances of centrifugal pumps.

  2. Modelling of flow with cavitation in centrifugal pump

    International Nuclear Information System (INIS)

    The paper concerns flow modelling in centrifugal pump with special consideration of cavitation phenomena. Cavitation occurs when local pressure drops below the saturation pressure according to the temperature of the flow. Vapour bubbles are created and then they flow through the areas with higher pressure. The bubbles collapse rapidly generating pressure wave, noise and vibration. Working under cavitation condition is very dangerous to a pump and can significantly shorten its lifetime. The investigated centrifugal pump consists of three two-flow rotors and stators working on a single shaft. The modelling process started with grid independence study. When the grid was chosen, the pump performance curve was obtained using the single phase fluid model. Next, using the results from pump performance curve calculations, the cavitation characteristic was obtained. The constant capacity was held when the pressure at the inlet was reduced. The two – phase model was used with Zwart cavitation model. The results indicate that the pump work in safe range of parameters. The analysis also provides wide range of information about the areas of vapour appearance. The most endangered regions are leading edges of rotor. When pressure at the inlet drops to about one third of pressure that calculations started from the cavitation cloud appears in whole rotor. The intense of vapour bubbles creation is greater near the shroud of the pump, rather than near the hub. As cavitation is strongly unsteady phenomena, the transient calculations were performed to check if the results are close to those obtained using the steady state type. The differences are not significant.

  3. Modelling of flow with cavitation in centrifugal pump

    Science.gov (United States)

    Homa, D.; Wróblewski, W.

    2014-08-01

    The paper concerns flow modelling in centrifugal pump with special consideration of cavitation phenomena. Cavitation occurs when local pressure drops below the saturation pressure according to the temperature of the flow. Vapour bubbles are created and then they flow through the areas with higher pressure. The bubbles collapse rapidly generating pressure wave, noise and vibration. Working under cavitation condition is very dangerous to a pump and can significantly shorten its lifetime. The investigated centrifugal pump consists of three two-flow rotors and stators working on a single shaft. The modelling process started with grid independence study. When the grid was chosen, the pump performance curve was obtained using the single phase fluid model. Next, using the results from pump performance curve calculations, the cavitation characteristic was obtained. The constant capacity was held when the pressure at the inlet was reduced. The two - phase model was used with Zwart cavitation model. The results indicate that the pump work in safe range of parameters. The analysis also provides wide range of information about the areas of vapour appearance. The most endangered regions are leading edges of rotor. When pressure at the inlet drops to about one third of pressure that calculations started from the cavitation cloud appears in whole rotor. The intense of vapour bubbles creation is greater near the shroud of the pump, rather than near the hub. As cavitation is strongly unsteady phenomena, the transient calculations were performed to check if the results are close to those obtained using the steady state type. The differences are not significant.

  4. Active magnetic bearings: As applied to centrifugal pumps

    Science.gov (United States)

    Nelik, Lev; Cooper, Paul; Jones, Graham; Galecki, Dennis; Pinckney, Frank; Kirk, Gordon

    1992-01-01

    Application of magnetic bearings to boiler feed pumps presents various attractive features, such as longer bearing life, lower maintenance costs, and improved operability through control of the rotordynamics. Magnetic bearings were fitted to an eight-stage, 600 hp boiler feed pump, which generates 2600 ft of heat at 680 gpm and 3560 rpm. In addition to the varied and severe operating environment in steady state operation of this pump in a power plant, it is also subjected to transient loads during frequent starts and stops. These loads can now be measured by the in-built instrumentation of the magnetic bearings. Following site installation, a follow-up bearing tune-up was performed, and pump transient response testing was conducted. The bearing response was completely satisfactory, ensuring trouble-free pump operation even in the range of reduced load. The experience gained so far through design and testing proves feasibility of magnetic bearings for boiler feed pumps, which sets the stage for application of even higher energy centrifugal pumps equipped with magnetic bearings.

  5. Internal Flow Measurement of a Very Low Specific-Speed Centrifugal Pump by PIV

    OpenAIRE

    Choi, Y.-D.; Kurokawa, Junichi; Nishino, K; Matsui, J.; Imamura, H.

    2002-01-01

    As the performance characteristics of a very low specific-speed centrifugal pump are much different from those of a normal specific-speed pump, there is strong demand of full understanding for the internal flow of the very low specific-speed centrifugal pump in order to improve the pump performance. The purpose of this study is to establish a method of visualization by PIV for a very low specific-speed centrifugal pump and to make clear the internal flow characteristics of the pump. Test pump...

  6. Cavitation Performance of a Centrifugal Pump with Water and Mercury

    Science.gov (United States)

    Hammitt, F. G.; Barton, R. K.; Cramer, V. F.; Robinson, M. J.

    1961-01-01

    The cavitation performance of a given centrifugal pump with water (hot and cold) and mercury is compared. It is found that there are significant scale effects with all fluids tested, with the Thoma cavitation parameter decreasing in all cases for increased pump speed or fluid Reynolds' number. The data for a fixed flow coefficient fall into a single curve when plotted against pump speed (or fluid velocity), rather than against Reynolds' number. Conversely, the Thoma parameter for a given Reynolds' number is approximately twice as large for mercury as for water. The direction of this variation is as predicted from consideration of the cavitation thermodynamic parameters which vary by a factor of 10(exp 7) between these fluids. No difference in cavitation performance between hot and cold water (approximately 160 F and 80 F) was observed, However, the thermodynamic parameters vary only by a factor of 5.

  7. Approaches to Stable Operation of Shaftless Centrifugal Pump

    Institute of Scientific and Technical Information of China (English)

    Ryunosuke Kawashima; Mitsuo Uno; Toshiaki Kanemoto

    2009-01-01

    The shaft-less impeller of the centrifugal pump, which is driven by the magnetic induction, was developed. The impeller rotates under the floating condition without any control device. The floating condition of the impeller is realized by utilizing the pressure in pump casing. The pump performance and the rotational behavior of the im-peUer were investigated experimentally. It has found that the floating position of the impeller become quite unsta-ble in a partial flow rate operation. And the pressure distribution at the casing wall affects the rotational posture of the impeller. This paper presents the effect of the casing treatment on the rotational posture of the impeller and the pressure distribution. The reasonable casing treatment is available for the stable rotational posture of the impeller.

  8. Study of blade clearance effects on centrifugal pumps

    Science.gov (United States)

    Hoshide, R. K.; Nielson, C. E.

    1972-01-01

    A program of analysis, design, fabrication, and testing has been conducted to develop and experimentally verify analytical models to predict the effects of impeller blade clearance on centrifugal pumps. The effect of tip clearance on pump efficiency, and the relationship between the head coefficient and torque loss with tip clearance was established. Analysis were performed to determine the cost variation in design, manufacture, and test that would occur between unshrouded and shrouded impellers. An impeller, representative of typical rocket engine impellers, was modified by removing its front shroud to permit variation of its blade clearances. It was tested in water with special instrumentation to provide measurements of blade surface pressures during operation. Pump performance data were obtained from tests at various impeller tip clearances. Blade pressure data were obtained at the nominal tip clearance. Comparisons of predicted and measured data are given.

  9. Prediction of centrifugal pump-cleaning ability in waste sludge

    International Nuclear Information System (INIS)

    Radioactive waste at the Savannah River Plant (SRP) is being transferred from older waste tanks to new, stress-relieved tanks for more effective waste management. The technology developed for waste removal involves the use of long-shaft, recirculating, centrifugal pumps (slurry pumps). Testing completed at the Savannah River Laboratory's 30-meter-diameter mock-up waste tank related the effective cleaning radius (ECR) of a slurry pump to critical pump and materials characteristics. Presently, this theory is being applied to radioactive waste at SRP. However, the technology can be applied to other remote handling situations where the slurry rheology can be determined. For SRP waste, an equation of the form: ECR α DV0 (rho/tau0)/sup 1/2/ was determined where D is the nozzle diameter, V0 is the average initial velocity, rho is the density of the slurry, and tau0 is the yield stress of the slurry. Using this relationship, the cleaning performance of a pump operating in any SRP sludge environment can be predicted. Specifically, yield stress and density measurements on sludge samples can be used to predict the required number and effective location for slurry pumps in actual SRP waste tanks

  10. Analysis of Centrifugal Pump in Diffuser Vane By Using CFD

    Directory of Open Access Journals (Sweden)

    V.R.Sivakumar

    2014-02-01

    Full Text Available Flow analysis in centrifugal pumps has long been an intensive subject of research. Computational Fluid Dynamics (CFD is the present day state are created in different parts of the pump at off radial gaps. The operating characteristic curves predicted by the numerical simulation were compared with the results of model testing and are found in good agreement. The test case consists of an enshrouded centrifugal impeller with seven blades and a radial vane diffuser with 7 vanes. A large number of measurements are available in the radial gap between the impeller and the diffuse, makin of steady and unsteady calculations of the flow in the pump are compared with the experimental ones, and four different turbulent models are analyzed. The steady K frozen rotor concept, while the unsteady simulation uses a fully resolved sliding grid approach. The comparisons show that the unsteady numerical results accurately predict the unsteadiness of the flow, demonstrating the validit and applicability of that methodology for unsteady incompressible turbo machinery flow computations. The steady approach is less accurate, with an unphysical advection of the impeller wakes, but accurate enough for a crude approximation. The different turbulence models predict the flow at the same level of accuracy, with slightly different results.

  11. The Effect of Viscosity on Performance of a Low Specific Speed Centrifugal Pump

    OpenAIRE

    Rouhollah Torabi; Seyyed Ahmad Nourbakhsh

    2016-01-01

    Centrifugal pump delivery head and flow rate drop effectively during the pumping of viscous fluids. Several methods and correlations have been developed to predict reduction rate in centrifugal pump performance when handling viscous fluids, but their results are not in very good agreement with each other. In this study, a common industrial low specific speed pump, which is extensively used in different applications, is studied. The entire pump, including impeller, volute, pipes, front and rea...

  12. Main characteristic parameters of centrifugal pump and safe operation of reactor

    International Nuclear Information System (INIS)

    Based on main characteristic parameters of centrifugal pump, the problems are discussed during the reactor operation. To High-Flux Engineering Test Reactor, ten-type typical faults are generalized in the reactor operation. Making use of basic knowledge of centrifugal pump, it can help reactor operators to find out whether centrifugal pump is out of order and to handle it. So, the safety of reactor can be assured

  13. Analyses of hydrodynamic radial forces on centrifugal pump impellers

    Science.gov (United States)

    Adkins, D. R.; Brennen, C. E.

    1988-01-01

    An experimental and theoretical study of the hydrodynamic interactions occurring between a centrifugal pump impeller and a volute is presented. The theoretical analysis provides a quasi-one-dimensional treatment of the flow in the volute, and it is extended to include the hydrodynamic force perturbations caused by the impeller whirling eccentrically in the volute. It is noted that these perturbations are often destabilizing. The theoretical models were found to accurately predict the radial forces caused by the flow through the impeller. The pressure acting on the front shroud of the impeller is shown to have a significant effect on the destabilizing hydrodyamic forces.

  14. Evaluation of a multiple disk centrifugal pump as an artificial ventricle.

    Science.gov (United States)

    Miller, G E; Sidhu, A; Fink, R; Etter, B D

    1993-07-01

    A multiple-disk centrifugal pump based on the Tesla Turbine design has been modified for potential use as an artificial ventricle or ventricular assist device. The pump consists of a series of interconnected parallel disks placed within a spiral volute housing. This pump normally operates as a continuous flow device; however, a controller circuit has been developed to also allow for pulsatile operation. Frequency, systolic duration, systolic rise time, and diastolic decay time can be independently controlled to produce a wide range of pulsatile pressures and flows. This pumping system was tested in vitro on a mock circulatory system using a blood analogue. Inlet and outlet pressures, outlet flow, and motor rotations per minute were continually monitored over a wide range of physiologic operating conditions. The disk pump output was compared with that of other artificial ventricles and produced favorable results. Direct experimental comparisons were made with a Harvard Apparatus pulsatile piston pump. Unlike the Harvard pump, the disk pump does not use valves. Rather, a slight forward rotation of the disks is used to offset the adverse diastolic pressure gradient, which avoids backflow through the device. PMID:8338431

  15. In Vitro Testing of a Novel Blood Pump Designed for Temporary Extracorporeal Support

    OpenAIRE

    Spurlock, DJ; Ranney, DN; Fracz, E; Mazur,; Bartlett, RH; Haft, JW

    2012-01-01

    Extracorporeal blood pumps are used as temporary ventricular assist devices or for extracorporeal membrane oxygenation. The ideal pump would be intrinsically self-regulating, carry no risk of cavitation or excessive inlet suction, be afterload insensitive, and valveless thus reducing thrombogenicity. Currently used technology, including roller, centrifugal, and pneumatic pulsatile pumps, does not meet these requirements. We studied a non-occlusive peristaltic pump (M-Pump) in two mock circula...

  16. Inlet and outlet devices for rotary blood pumps.

    Science.gov (United States)

    Song, Xinwei; Wood, Houston G; Allaire, Paul E; Antaki, James F; Olsen, Don B

    2004-10-01

    The purposes of inlet and outlet devices for rotary blood pumps, including inducers and diffusers for axial pumps, inlet and exit volutes for centrifugal pumps, and inlet and outlet cannulas, are to guide the blood into the impeller, where the blood is accelerated, and to convert the high kinetic energy into pressure after the impeller discharge, respectively. The designs of the inlet and outlet devices have an important bearing on the pump performance. Their designs are highly dependent on computational fluid dynamics (CFD) analysis, guided by intuition and experience. For inlet devices, the design objectives are to eliminate separated flow, to minimize recirculation, and to equalize the radial components of velocity. For outlet devices, the design goals are to reduce speed, to minimize energy loss, and to avoid flow separation and whirl. CFD analyses indicate the velocity field and pressure distribution. Geometrical optimization of these components has been implemented in order to improve the flow pattern. PMID:15384997

  17. Exit flow measurements of a centrifugal pump impeller

    International Nuclear Information System (INIS)

    Discharge flows from a centrifugal pump impeller with a specific speed of 150 [rpm, m3/min, m] were experimentally investigated. A large axisymmetric collector instead of a volute casing was installed to obtain circumferentially uniform flow, i.e. without interaction of the impeller and the volute. The unsteady flow was measured at the impeller exit and vaneless diffuser using a hot film probe and a pressure transducer. The flow at impeller exit showed pronounced jet-wake flow patterns. The wake, which was on the suction/hub side at high flow rate, became enlarged pitchwisely on both the hub and the shroud side as the flow rate decreases. The pitchwise non-uniformity of the flow rapidly decreased along the downstream and the non-uniformity almost disappeared at radius ratio of 1.18 for medium flow rate. The mean vaneless diffuser flow was reasonably predicted using a one dimensional analysis when an empirical constant was used to specify the skin friction coefficient. The data can be used for a centrifugal pump impeller design and validation of CFD codes and flow modeling

  18. Influence of clearance model on numerical simulation of centrifugal pump

    Science.gov (United States)

    Wang, Z.; Gao, B.; Yang, L.; Du, W. Q.

    2016-05-01

    Computing models are always simplified to save the computing resources and time. Particularly, the clearance that between impeller and pump casing is always ignored. But the completer model is, the more precise result of numerical simulation is in theory. This paper study the influence of clearance model on numerical simulation of centrifugal pump. We present such influence via comparing performance, flow characteristic and pressure pulsation of two cases that the one of two cases is the model pump with clearance and the other is not. And the results show that the head decreases and power increases so that efficiency decreases after computing with front and back cavities. Then no-leakage model would improve absolute velocity magnitude in order to reach the rated flow rate. Finally, more disturbance induced by front cavity flow and wear-ring flow would change the pressure pulsation of impeller and volute. The performance of clearance flow is important for the whole pump in performance, flow characteristic, pressure pulsation and other respects.

  19. Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

    OpenAIRE

    Babayigit Osman; Kocaaslan Osman; Aksoy Muharrem Hilmi; Guleren Kursad Melih; Ozgoren Muammer

    2015-01-01

    Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics sof...

  20. Determination of Possible Wear on the Centrifugal Pump Wheel Used for Agricultural Irrigation Purposes

    OpenAIRE

    Yuksel, E; B. Eker

    2009-01-01

    The extent of this work is operating characteristics of a horizontal shafted centrifugal pump which has been operated for 6 ½ to 7 hours on the average. A closed circuit pump system (circulating within itself) which was formed by attaching a horizontal shafted centrifugal pump which can be used in irrigation applications with a drum has been operated for 180 hours at laboratory conditions. To define the operating properties of the pump, its operating characteristics were measured in respect t...

  1. A modal approach for vibration analysis and condition monitoring of a centrifugal pump

    OpenAIRE

    Ramana Podugu; J.Suresh Kumar*; B.V.Ramana murthy; N.Syam Kumar

    2011-01-01

    The modal analysis of the centrifugal pump and its assembly is performed using FEM technology. The mathematical model and FEA model are built for the original centrifugal casing and simulation is made to find the pump natural frequencies. The first ten natural frequencies were compared to pump operating speed and their multiples up to pump vane passing frequency as per HIS (Hydraulic Institute Standards -9.6.4-2000) guidelines. In the original design, the first natural frequency in vertical d...

  2. A REVIEW PAPER ON DEVELOPMENT OF IMPELLER OF CENTRIFUGAL PUMP USING COMPUTATIONAL FLUID DYNAMICS

    Directory of Open Access Journals (Sweden)

    Mr. Nilesh Nemgonda Patil

    2015-09-01

    Full Text Available Nowadays, the centrifugal pumps became very popular because of recent development of high speed electric motors, steam turbines etc.Centrifugal pumps can be single-stage or may be multistage pumps. It depends upon the number of impellers used in the pump. Single stage pump consists of only one impeller while in multistage pumps the impellers are mounted in the series in pumps. These Centrifugal pumps can be analyzed by software code like Computational Fluid Dynamics (CFD.This CFD tool or code helps to optimize the pump performance. The complex internal flows are to be predicted with the CFD code. The optimized pumps are used for various applications like drainage and drinking water system, chemical Industries- Catalyst transfer, acid transfer and neutralizing, waste water/Chemicals- Industrial effluents, purifying water, in process industriespaper pulp, chemicals, and pharmaceuticals etc

  3. Numerical Calculation of the Three-Dimensional Swirling Flow Inside the Centrifugal Pump Volutes

    Directory of Open Access Journals (Sweden)

    E. Cezmi Nursen

    2003-01-01

    Full Text Available The flow inside the volute of a centrifugal pump is threedimensional and, depending upon the position of the inlet relative to the cross-section center line, a single or double swirling flow occurs. The purpose of this study was the calculation of the three-dimensional swirling flow inside the centrifugal pump volute.

  4. Method for Reducing Pumping Damage to Blood

    Science.gov (United States)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Robert J. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    Methods are provided for minimizing damage to blood in a blood pump wherein the blood pump comprises a plurality of pump components that may affect blood damage such as clearance between pump blades and housing, number of impeller blades, rounded or flat blade edges, variations in entrance angles of blades, impeller length, and the like. The process comprises selecting a plurality of pump components believed to affect blood damage such as those listed herein before. Construction variations for each of the plurality of pump components are then selected. The pump components and variations are preferably listed in a matrix for easy visual comparison of test results. Blood is circulated through a pump configuration to test each variation of each pump component. After each test, total blood damage is determined for the blood pump. Preferably each pump component variation is tested at least three times to provide statistical results and check consistency of results. The least hemolytic variation for each pump component is preferably selected as an optimized component. If no statistical difference as to blood damage is produced for a variation of a pump component, then the variation that provides preferred hydrodynamic performance is selected. To compare the variation of pump components such as impeller and stator blade geometries, the preferred embodiment of the invention uses a stereolithography technique for realizing complex shapes within a short time period.

  5. Small centrifugal pumps for low-thrust rocket engines

    Science.gov (United States)

    Furst, R. B.

    1986-01-01

    Six small, low specific speed centrifugal pump configurations were designed, fabricated, and tested. The configurations included shrouded, and 25 and 100% admission open face impellers with 2 inch tip diameters; 25, 50, and 100% emission vaned diffusers; and volutes with conical exits. Impeller tip widths varied from 0.030 inch to 0.052 inch. Design specific speeds (N sub s = RPM*GPM**0.5.FT**0.75) were 430 (four configurations) and 215 (two configurations). The six configurations were tested with water as the pumped fluid. Noncavitating performance results are presented for the design speed of 24,500 rpm over a flowrate range from 1 to 6 gpm for the N sub s = 430 configurations and test speeds up to 29,000 rpm over a flowrate range from 0.3 to 1.2 gpm for the N sub s = 215 configurations. Cavitating performance results are presented over a flowrate range from 60 to 120% of design flow. Fabrication of the small pump conponents is also discussed.

  6. Transient analysis of charging system with centrifugal charging pumps

    International Nuclear Information System (INIS)

    The CARD (CVCS Analysis for Design) code has been developed for the transient analysis of the letdown and charging system of Korea Standard Nuclear Power Plant. The computer code has been already verified and validated by comparing with actual test results. Analyzed in this paper are the flow and pressure transients in the charging line. The sensitivity studies are performed to select the acceptable control parameters of charging line backpressure controller and seal injection flow controller. In addition, the seal injection system transient is evaluated for the pressurizer auxiliary spray operation. It is shown that the charging line backpressure controller control parameters yield a significant effect on the charging system stability. The results obtained from this study will be used to verify the system design and to select the optimum control parameters for the charging system with centrifugal charging pumps

  7. Origins of hydrodynamic forces on centrifugal pump impellers

    Science.gov (United States)

    Adkins, Douglas R.; Brennen, Christopher E.

    1987-01-01

    Hydrodynamic interactions that occur between a centrifugal pump impeller and volute are experimentally and theoretically investigated. The theoretical analysis considers the inability of the blades to perfectly guide the flow through the impeller, and also includes a quasi-one dimensional treatment of the flow in the volute. The disturbance at the impeller discharge and the resulting forces are determined by the theoretical model. The model is then extended to obtain the hydrodynamic force perturbations that are caused by the impeller whirling eccentrically in the volute. Under many operating conditions, these force perturbations were found to be destablizing. Comparisons are made between the theoretical model and the experimental measurements of pressure distributions and radial forces on the impeller. The theoretical model yields fairly accurate predictions of the radial forces caused by the flow through the impeller. However, it was found that the pressure acting on the front shroud of the impeller has a substantial effect on the destablizing hydrodynamic forces.

  8. DETECTION OF CAVITATION IN CENTRIFUGAL PUMP BY VIBRATION METHODS

    Institute of Scientific and Technical Information of China (English)

    NI Yongyan; YUAN Shouqi; PAN Zhongyong; YUAN Jianping

    2008-01-01

    For the purpose of detecting the cavitation of centrifugal pump onsite and real time, the vibration signals on varied operation conditions of both cavitation and non-cavitation obtained through acceleration sensors were analyzed. When cavitation occurs, the cavities near the leading edge of the blade will appear periodic oscillating, which will induce quasi-synchronous vibration. The frequency of the quasi-synchronous vibration symmetrically appears on the two sides of the blade passing frequency, by which the cavitation incipiency can be detected. During the developing process of the cavitation, as the severe complexity of the unsteady flow, it is very difficult to detect the development of cavitation by classical analysis methods. Fractal method of Higuchi is successfully used for detecting the incipiency, fully development of cavitation and the development between them.

  9. EXPERIMENTAL STUDY ON HIGH-SPEED CENTRIFUGAL PUMPS WITH DIFFERENT IMPELLERS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The experimental study is carded out on high-speed centrifugal pumps with three different impellers. The ex-perimental results and analysis show that high-speed centrifugal pumps with a closed complex impeller can achieve thehighest efficiency and the lowest head coefficient followed by those with half-open impeller and open-impeller, and canobtain much easily stable head-capacity characrastic curve, while those with a half-open complex impeller can't. Thecharacteristic curve with a open impeller is almost constant horizontal line before dropping sharply. The results also showthat the axial clearance between pump casing and impeller can influence greatly on the performance of centrifugal pumps.

  10. Research on energy conversion mechanism of rotodynamic pump and design of non-overload centrifugal pump

    Science.gov (United States)

    Zhang, X. L.; Hu, S. B.; Shen, Z. Z.; Wu, S. P.; Li, K.

    2016-05-01

    In this paper, an attempt has been made for the calculation of an expression for the intrinsic law of input power which has not yet been given by current theory of Rotodynamic pump. By adequate recognition of the characteristics of non-inertial system within the rotating impeller, it is concluded that the input power consists of two power components, the first power component, whose magnitude increases with the increase of the flow rate, corresponds to radial velocity component, and the second power component, whose magnitude decreases with the increase of the flow rate, corresponds to tangential velocity component, therefore, the law of rise, basic levelness and drop of input power curves of centrifugal pump, mixed-flow pump and axial-flow pump can be explained reasonably. Through further analysis, the main ways for realizing non-overload of centrifugal pump are obtained, and its equivalent design factor is found out, the factor correlates with the outlet angle of leading face and back face of the blade, wrap angle, number of blades, outlet width, area ratio, and the ratio of operating flow rate to specified flow rate and so on. These are verified with actual example.

  11. EXPERIMENTAL INVESTIGATION OF FLOW INSTABILITIES AND ROTATING STALL IN A HIGH-ENERGY CENTRIFUGAL PUMP STAGE

    OpenAIRE

    Berten, Stefan; Dupont, Philippe; Fabre, Laurent; Kayal, Maher; Avellan, Francois; Farhat, Mohamed

    2009-01-01

    In centrifugal pumps, the interaction between the rotating impeller and the stationary diffuser generates specific pressure fluctuation patterns. When the pump is operated at off design conditions, these pressure fluctuations increase. The resulting rise of mechanical vibration levels may negatively affect the operational performance and the life span of mechanical components. This paper presents detailed pressure fluctuation measurements performed in a high speed centrifugal pump...

  12. Vibration Characteristics Induced by Cavitation in a Centrifugal Pump with Slope Volute

    OpenAIRE

    Ning Zhang; Minguan Yang; Bo Gao; Zhong Li

    2015-01-01

    Cavitation is one of the instability sources in centrifugal pump, which would cause some unexpected results. The goal of this paper was to analyze the influence of cavitation process on different frequency bands in a centrifugal pump with slope volute. And special attention was paid to low frequency signals, which were often filtered in the reported researches. Results show that at noncavitation condition, vibration level is closely related to flow structure interior pump. At partial flow rat...

  13. Startup Characteristics of a Centrifugal Pump Delivering Gas-Liquid Two-Phase Flow

    OpenAIRE

    Yu-Liang Zhang; Jun-Jian Xiao; Jian-Ping Yu; Ying-Yu Ji

    2014-01-01

    The transient performance of centrifugal pumps during the startup period has drawn more and more attention in recent years due to urgent engineering needs. In order to make certain the transient startup characteristics of a high specific-speed prototype centrifugal pump delivering the gas-liquid two-phase flow, the transient flows inside the pump are numerically simulated during the startup period using the dynamic slip region method in this paper. The results show that the difference in head...

  14. Optimization and Analysis of Centrifugal Pump considering Fluid-Structure Interaction

    OpenAIRE

    Yu Zhang; Sanbao Hu; Yunqing Zhang; Liping Chen

    2014-01-01

    This paper presents the optimization of vibrations of centrifugal pump considering fluid-structure interaction (FSI). A set of centrifugal pumps with various blade shapes were studied using FSI method, in order to investigate the transient vibration performance. The Kriging model, based on the results of the FSI simulations, was established to approximate the relationship between the geometrical parameters of pump impeller and the root mean square (RMS) values of the displacement response at ...

  15. Experimental Investigation and Passive Flow Control of a Cavitating Centrifugal Pump

    OpenAIRE

    Spyridon D. Kyparissis; Dionissios P. Margaris

    2012-01-01

    Passive flow control techniques are used to improve the flow field and efficiency of centrifugal pumps and turbomachines, in general. An important phenomenon that mechanical engineers have to take into account is cavitation. It leads to the decrease of the pump performance and total head. In the present experimental study, a centrifugal pump is investigated in cavitating conditions. A passive flow control is realized using three different blade leading edge angles in order to reduce the cavit...

  16. Intelligent Diagnosis Method for Centrifugal Pump System Using Vibration Signal and Support Vector Machine

    OpenAIRE

    Hongtao Xue; Zhongxing Li; Huaqing Wang; Peng Chen

    2014-01-01

    This paper proposed an intelligent diagnosis method for a centrifugal pump system using statistic filter, support vector machine (SVM), possibility theory, and Dempster-Shafer theory (DST) on the basis of the vibration signals, to diagnose frequent faults in the centrifugal pump at an early stage, such as cavitation, impeller unbalance, and shaft misalignment. Firstly, statistic filter is used to extract the feature signals of pump faults from the measured vibration signals across an optimum ...

  17. Simulation and sensitivity analysis on process of switching double centrifugal pump

    International Nuclear Information System (INIS)

    The experimental and simulating processes of switching centrifugal pump in the double centrifugal pump water supply system were studied. The experiment results verified the validity of the model. Based on the sensitivity analysis of the experimental process with the model, we can get the following conclusions: In the process of switching centrifugal pump in the double centrifugal pump water supply system, the smaller the system flow and the greater the centrifugal moment of inertia, the greater the loss water, the smaller the minimum flow rate, the longer the system recovery stability; the smaller the characteristic time of the check valves, the more stable the flow volatility of the main circuit, but the volatility of the system flow during switching is very limited. (authors)

  18. Numerical studies in a centrifugal pump with the improved blade considering cavitation

    Science.gov (United States)

    Song, P. F.; Zhang, Y. X.; Xu, C.; Zhou, X.; Zhang, J. Y.

    2015-01-01

    In this paper, a centrifugal pump with the improved blade for cavitation is studied numerically. A 3D impeller with logarithmic spiral blade profile was designed by the in-house hydraulic design code using a centrifugal pump geometric parameters, and the blade profile curve of suction side on the designed impeller is replaced by a combination of tangent line and circle arc line. The cavitation flows in the centrifugal pump with designed impeller, modified impeller and centrifugal pump spectrum impeller are respectively calculated by two-phase CFD simulation at three flow rates. The tests of the centrifugal pump have been conducted to verify numerical simulation. The effects of designed impeller and modified impeller on hydraulic efficiency, critical cavitation number, cavitation length, head drop performance and vapor cavity distribution in impeller are investigated. The results show that the modification of blade profile curve of suction side can improve the cavitation performance of an impeller and hydraulic efficiency of centrifugal pump. Compared with designed impeller, the critical cavitation number of centrifugal pump with modified impeller decrease by 26.5% under the same flow rate coefficient, and the cavitation intensity in the modified impeller is weakened effectively. The hydraulic efficiency of modified impeller also increases by 4.9%.

  19. Optimization and analysis of centrifugal pump considering fluid-structure interaction.

    Science.gov (United States)

    Zhang, Yu; Hu, Sanbao; Zhang, Yunqing; Chen, Liping

    2014-01-01

    This paper presents the optimization of vibrations of centrifugal pump considering fluid-structure interaction (FSI). A set of centrifugal pumps with various blade shapes were studied using FSI method, in order to investigate the transient vibration performance. The Kriging model, based on the results of the FSI simulations, was established to approximate the relationship between the geometrical parameters of pump impeller and the root mean square (RMS) values of the displacement response at the pump bearing block. Hence, multi-island genetic algorithm (MIGA) has been implemented to minimize the RMS value of the impeller displacement. A prototype of centrifugal pump has been manufactured and an experimental validation of the optimization results has been carried out. The comparison among results of Kriging surrogate model, FSI simulation, and experimental test showed a good consistency of the three approaches. Finally, the transient mechanical behavior of pump impeller has been investigated using FSI method based on the optimized geometry parameters of pump impeller. PMID:25197690

  20. Numerical Study of a Fuel Centrifugal Pump with Variable Impeller Width for Aero-engines

    Science.gov (United States)

    Wang, Bin; Guan, Huasheng; Ye, Zhifeng

    2015-12-01

    As typical pump with large flow rate and high reliability, centrifugal pumps in fuel system of aero-engines mostly regulate flow rate by flow bypass, which leads to low efficiency and large fuel temperature rise especially at low flow rate. An innovative fuel centrifugal pump with variable impeller width is a more effective way to regulate flow rate than flow bypass. To find external characteristics of the centrifugal pump with variable impeller width proposed in this paper, flow domain within the pump is simulated numerically and some primary performance parameters and their correlation are analyzed. Results show that flow rate of the pump can be regulated by variable impeller width and that efficiency for this scheme is higher than that for flow bypass. The higher outlet static pressure the pump runs at, the wider range of flow rates can be obtained with stronger nonlinear relationship between flow rate and impeller width.

  1. Effect of Blade Exit Shape on Performance and Vibration of a Double Volute Centrifugal Pump

    OpenAIRE

    Atia E. Khalifa

    2014-01-01

    The fluid-structure interaction phenomenon is the main cause of flow-induced vibrations at the blade passing frequency in large and high pressure centrifugal pumps. One way to reduce the effects of this interaction and pump vibration is to increase the effective gap by cutting the blade exit of the impeller. However, this cut of the impeller blade will affect the pump head and the flow pattern inside the pump volute. A single stage of a double volute centrifugal pump is used to investigate th...

  2. Roller and Centrifugal Pumps: A Retrospective Comparison of Bleeding Complications in Extracorporeal Membrane Oxygenation.

    Science.gov (United States)

    Halaweish, Ihab; Cole, Adam; Cooley, Elaine; Lynch, William R; Haft, Jonathan W

    2015-01-01

    Centrifugal pumps are increasingly used for extracorporeal membrane oxygenation (ECMO) rather than roller pumps. However, shear forces induced by these types of continuousflow pumps are associated with acquired von Willebrand factor deficiency and bleeding complications. This study was undertaken to compare adverse bleeding complications with the use of centrifugal and roller pumps in patients on prolonged ECMO support. The records of all adult ECMO patients from June 2002 to 2013 were retrospectively reviewed using the University of Michigan Health System database and the Extracorporeal Life Support Organization registry, focusing on patients supported for at least 5 days. Ninety-five ECMO patients met criteria for inclusion (48 roller vs. 47 centrifugal pump). Indications included pulmonary (79%), cardiac (15%), and extracorporeal cardiopulmonary resuscitation (6%), without significant difference between the two groups. Despite lower heparin anticoagulation (10.9 vs. 13.7 IU/kg/hr) with centrifugal pumps, there was a higher incidence of nonsurgical bleeding (gastrointestinal, pulmonary, and neurological) in centrifugal pump patients (26.1 vs. 9.0 events/1,000 patient-days, p = 0.024). In conclusion, in our historical comparison, despite reduced anticoagulation, ECMO support using centrifugal pumps was associated with a higher incidence of nonsurgical bleeding. The mechanisms behind this are multifactorial and require further investigation. PMID:25914954

  3. Numerical experiment optimization to obtain the characteristics of the centrifugal pump steps package

    Science.gov (United States)

    Boldyrev, S. V.; Boldyrev, A. V.

    2014-12-01

    The numerical simulation method of turbulent flow in a running space of the working-stage in a centrifugal pump using the periodicity conditions has been formulated. The proposed method allows calculating the characteristic indices of one pump step at a lower computing resources cost. The comparison of the pump characteristics' calculation results with pilot data has been conducted.

  4. Computational Fluid Dynamics Analysis of Blade Tip Clearances on Hemodynamic Performance and Blood Damage in a Centrifugal Ventricular Assist Device

    OpenAIRE

    Wu, Jingchun; Paden, Bradley E.; Borovetz, Harvey S.; Antaki, James F.

    2009-01-01

    An important challenge facing the design of turbodynamic ventricular assist devices (VADs) intended for long-term support is the optimization of the flow path geometry to maximize hydraulic performance while minimizing shear-stress-induced hemolysis and thrombosis. For unshrouded centrifugal, mixed-flow and axial-flow blood pumps, the complex flow patterns within the blade tip clearance between the lengthwise upper surface of the rotating impeller blades and the stationary pump housing have a...

  5. Performance and internal flow condition of mini centrifugal pump with splitter blades

    International Nuclear Information System (INIS)

    Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. The blade-to-blade low velocity regions are suppressed in the case with the splitter blades and the total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

  6. Performance and internal flow condition of mini centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Kaji, K.; Wada, T.

    2012-11-01

    Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. The blade-to-blade low velocity regions are suppressed in the case with the splitter blades and the total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

  7. 77 FR 65360 - Grant of Authority for Subzone Status (Centrifugal and Submersible Pumps); Auburn, NY

    Science.gov (United States)

    2012-10-26

    ... subzone at the centrifugal and submersible pump manufacturing and warehousing facilities of Xylem Water..., filed 10-21-2011); Whereas, notice inviting public comment has been given in the Federal Register (76 FR... Foreign-Trade Zones Board Grant of Authority for Subzone Status (Centrifugal and Submersible...

  8. Numerical Calculation of the Three-Dimensional Swirling Flow Inside the Centrifugal Pump Volutes

    OpenAIRE

    Nursen C. E.; Ayder E.

    2003-01-01

    The flow inside the volute of a centrifugal pump is threedimensional and, depending upon the position of the inlet relative to the cross-section center line, a single or double swirling flow occurs. The purpose of this study was the calculation of the three-dimensional swirling flow inside the centrifugal pump volute.The developed flow solver provides detailed pressure and velocity distribution information inside the volute, and the calculated results are verified by means of the experimental...

  9. Influence of Prewhirl Regulation by Inlet Guide Vanes on Cavitation Performance of a Centrifugal Pump

    OpenAIRE

    Lei Tan; Baoshan Zhu; Shuliang Cao; Yuchuan Wang; Binbin Wang

    2014-01-01

    The influence of prewhirl regulation by inlet guide vanes (IGVs) on a centrifugal pump performance is investigated experimentally and numerically. The experimental results show that IGVs can obviously change the head and increase the efficiency of the tested centrifugal pump over a wide range of flow rates. Although the cavitation performance is degraded, the variation of the cavitation critical point is less than 0.5 m. Movement of the computed three-dimensional streamlines in suction pipe a...

  10. Analysis on Energy Conversion of Screw Centrifugal Pump in Impeller Domain Based on Profile Lines

    OpenAIRE

    Hui Quan; Rennian Li; Qingmiao Su; Wei Han; Pengcheng Wang

    2013-01-01

    In order to study the power capability of impeller and energy conversion mechanism of screw centrifugal pump, the methods of theoretical analysis and numerical simulation by computational fluid dynamics theory (CFD) were adopted, specifically discussing the conditions of internal flow such as velocity, pressure, and concentration. When the medium is sand-water two-phase flow and dividing the rim of the lines and wheel lines of screw centrifugal pump to segments to analyze energy conversion ca...

  11. Numerical studies of the velocity distribution within the volute of a centrifugal pump

    OpenAIRE

    Al-Obaidi, Ahmed; Pradhan, Suman; Asim, Taimoor; Mishra, Rakesh; Zala, Karina

    2014-01-01

    Centrifugal pumps play an essential role in engineering systems since they are widely used in the process and power industries. The performance of a centrifugal pump needs to be maximised due to its importance and this depends on the flow structure within the pump. The flow structure within a pump is very complex due to the presence of a rotating impeller and its interaction with the volute casing. In this paper, a numerical investigation using CFD analysis has been carried out to determine t...

  12. Study on High-Speed Centrifugal-Regenerative Pump with an Inducer

    Institute of Scientific and Technical Information of China (English)

    朱祖超; 陈鹰; 金庆明; 黄敦回

    2002-01-01

    The study on high-speed centrifugal-regenerative pumps with an inducer (HCRP) is carried out. Thecombined structure of inducer, centrifugal impeller, and regenerative impeller is presented, and a theoretical parallelcombinatorial hydraulic design method is investigated. The comparative experimental results show that efficiency insmaller capacity region, head coefficient and efficiency in larger capacity region of HCRPs is few lower, much higherand lower than those of high-speed centrifugal pumps, respectively, anci that the suction performance of HCRPs isdetermined only by inducer. HCRPs can be more suitably applied to deliver small-capacity high-head liquids inchemical and petrochemical industries.

  13. Parametric Study and Design Optimization of Centrifugal Pump Impeller-A Review

    Directory of Open Access Journals (Sweden)

    Vijaypratap R Singh ,

    2014-01-01

    Full Text Available Centrifugal pumps are widely used for irrigation, water supply plants, steam power plants, sewage, oil refineries, chemical plants, hydraulic power service, food processing factories and mines, because of their suitability in practically any service. Therefore it is necessary to find out the design parameters and working conditions that yield optimal output and maximum efficiency with lowest power consumption. Study indicates that Computational fluid dynamics (CFD analysis is being increasingly applied in the design of centrifugal pumps. With the aid of the CFD approach, the complex internal flows in water pump impellers, can be well predicted, to speed up the pump design procedure. This paper exposes the various research work carried out in this direction especially in the content of parametric study and optimization of centrifugal pump impeller using CFD tool and DoE technique. Literature surveys indicate that very restricted work has been done in this area.

  14. Unsteady internal flow conditions of mini-centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Kaji, K.; Wada, T.

    2013-02-01

    Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional unsteady numerical flow analysis was conducted to investigate the change of the internal flow according to the rotor rotation. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the splitter blades. The blade-to-blade low velocity region was suppressed in the case with the splitter blades. In addition to that, the unsteady flows near the volute casing tongue were suppressed due to the splitter blades. In the present paper, the performance of the mini centrifugal pump is shown and the unsteady flow condition is clarified with the results of the numerical flow analysis. Furthermore, the effects of the splitter blades on the performance and the unsteady internal flow condition are investigated.

  15. 2011 IEEE Visualization Contest Winner: Visualizing Unsteady Vortical Behavior of a Centrifugal Pump

    KAUST Repository

    Otto, Mathias

    2012-09-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump\\'s effectiveness. The winning entry split analysis of the pump into three parts based on the pump\\'s functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/ oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump. © 2012 IEEE.

  16. Experimental and numerical study of a centrifugal pump in the performance of viscous flow

    International Nuclear Information System (INIS)

    For pumping viscous fluids like oil and petrochemical products, by using the centrifugal pumps, fluid flow rate and pumping head are smaller than that of water, while the required power is increased. This is due to increased frictional losses in impeller passages. The characteristic curves for pumps, offered by different manufacturers are exclusively for water and can not be valid for viscous fluids. In the present project a centrifugal pump manufactured by pump iran has been tested on a test bed for different industrial oils as well as water. In order to investigate the effect of different design parameters on pump characteristics, a new impeller has been designed with reduced number of blades, the shroud has been taken away and with new dimensions for blades. The results obtained from different oil tests indicate that head, capacity and efficiency are increased. The numerical simulation of fluid flow inside the passage of impellers for two model by fluent code confirmed the results of hydraulic tests

  17. Research on energy conversion mechanism of a screw centrifugal pump under the water

    International Nuclear Information System (INIS)

    In order to research screw centrifugal pump impeller power capability and energy conversion mechanism, we used Navier-Stokes equation and standard k-ε equation turbulence model on the basis of the Euler equations to carry out screw centrifugal pump internal flow numerical simulation. This was explored by simulating specific design conditions; the medium is water, variation of speed and pressure of flow filed under the action of the impeller, and the screw centrifugal impeller shroud line and wheel line segment take monitoring sites. The monitoring points are between dynamic head and static head change to analyze the energy conversion capability along the impeller corners of screw centrifugal pump. The results show that the energy of fluid of the screw centrifugal pump is provided by spiral segment, the spiral segment in front of the impeller has played a multi-level role, it has significant reference value to research the energy conversion mechanism of screw centrifugal pump under solid-liquid two phase

  18. Optimization of Centrifugal Pump Characteristic Dimensions for Mechanical Circulatory Support Devices.

    Science.gov (United States)

    Korakianitis, Theodosios; Rezaienia, Mohammad A; Paul, Gordon M; Rahideh, Akbar; Rothman, Martin T; Mozafari, Sahand

    2016-01-01

    The application of artificial mechanical pumps as heart assist devices impose power and size limitations on the pumping mechanism, and therefore requires careful optimization of pump characteristics. Typically new pumps are designed by relying on the performance of other previously designed pumps of known performance using concepts of fluid dynamic similarity. Such data are readily available for industrial pumps, which operate in Reynolds numbers region of 10. Heart assist pumps operate in Reynolds numbers of 10. There are few data available for the design of centrifugal pumps in this characteristic range. This article develops specific speed versus specific diameter graphs suitable for the design and optimization of these smaller centrifugal pumps concentrating in dimensions suitable for ventricular assist devices (VADs) and mechanical circulatory support (MCS) devices. A combination of experimental and numerical techniques was used to measure and analyze the performance of 100 optimized pumps designed for this application. The data are presented in the traditional Cordier diagram of nondimensional specific speed versus specific diameter. Using these data, nine efficient designs were selected to be manufactured and tested in different operating conditions of flow, pressure, and rotational speed. The nondimensional results presented in this article enable preliminary design of centrifugal pumps for VADs and MCS devices. PMID:27258221

  19. Capabilities of Numerical Simulation of Multiphase Flows in Centrifugal Pumps using Modern CFD Software

    CERN Document Server

    Kochevsky, A N

    2005-01-01

    The paper describes capabilities of numerical simulation of liquid flows with solid and/or gas admixtures in centrifugal pumps using modern commercial CFD software packages, with the purpose to predict performance curves of the pumps treating such media. In particular, the approaches and multiphase flow models available in the package CFX-5 are described; their advantages and disadvantages are analyzed.

  20. Flow instability of a centrifugal pump determined using the energy gradient method

    Science.gov (United States)

    Li, Yi; Dong, Wenlong; He, Zhaohui; Huang, Yuanmin; Jiang, Xiaojun

    2015-02-01

    The stability of the centrifugal pump has not been well revealed because of the complexity of internal flow. To analyze the flow characteristics of a centrifugal pump operating at low capacity, methods of numerical simulation and experimental research were adopted in this paper. Characteristics of the inner flow were obtained. Standard k-ɛ turbulence models were used to calculate the inner flow of the pump under off-design conditions. The distribution of the energy gradient function K was obtained by three-dimensional numerical simulation at different flow rates. The relative velocity component was acquired from the absolute velocity obtained in particle image velocimetry. By comparing with experimental results, it was found that flow instability occurs at the position of maximum K. The flow stability reduces with an increasing flow rate. The research results provide a theoretical basis for the optimization design of a centrifugal pump.

  1. Performance analysis on solid-liquid mixed flow in a centrifugal pump

    Science.gov (United States)

    Ning, C.; Wang, Y.

    2016-05-01

    In order to study the solid-liquid mixed flow hydraulic characteristics of centrifugal pump, the Pro/E software was used for three-dimensional modeling of centrifugal pump chamber. By using the computational fluid dynamics software CFX, the numerical simulation calculation of solid-liquid two-phase flow within whole flow passage of centrifugal pump was conducted. Aim at different particle diameters, the Reynolds-averaged N-S equations with the RNG k-Ɛ turbulence model and SIMPLEC algorithm were used to simulate the two-phase flow respectively on the condition of different volume fraction. The influence of internal flow characteristic on pump performance was analyzed. On the conditions of different particle diameter and different volume fraction, the turbulence kinetic energy and particle concentration are analyzed. It can be found that the erosion velocity ratio on the flow channel wall increases along with the increasing of the volume fraction

  2. Critical cavitation coefficient analysis of a space low specific centrifugal pump with micro gravity

    Science.gov (United States)

    Liu, J. T.; Li, Y.; Gao, Y.; Hu, Q.; Zhou, C.; Wu, Y. L.

    2016-05-01

    Centrifugal pump was used in the loop as a baselined unit. The flow rate of the pump was very small, while the head was high. This space pump must work stable for a long time (more than a year), so the performance of the pump attracted public attention. The rotational speed of the impeller was limited for stability, so the pump belonged to low specific centrifugal pump. In this paper, a single-phase centrifugal pump, which was designed for single-phase fluid loops in satellites, was modeled for numerical simulation. The hydraulic region of the pump was discretized by structured mesh. Three dimensional (3-D) flow in the pump was studied by the use of computational fluid dynamics. Partially-Averaged Navier- Stokes (PANS) model based on RNG k-ε turbulence model was developed for the simulation of the unsteady flow. Velocity inlet and pressure outlet was used as the boundary conditions. Interface was used between the impeller and the casing, as well as the impeller and inlet pipe. Performances and pressure fluctuation of the pump were investigated. The dominant frequency of the pressure fluctuation is blade passing frequency at the region close to the tongue of the casing, while it is twice of blade passing frequency at the other region.

  3. Preclinical study of a novel hydrodynamically levitated centrifugal pump for long-term cardiopulmonary support : In vivo performance during percutaneous cardiopulmonary support.

    Science.gov (United States)

    Tsukiya, Tomonori; Mizuno, Toshihide; Takewa, Yoshiaki; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2015-12-01

    An extracorporeal centrifugal blood pump with a hydrodynamically levitated impeller was developed for use in a durable extracorporeal membrane oxygenation (ECMO) system. The present study examined the biocompatibility of the blood pump during long-term use by conducting a series of 30-day chronic animal experiments. The ECMO system was used to produce a percutaneous venoarterial bypass between the venae cavae and carotid artery in adult goats. No anticoagulation or antiplatelet therapy was administered during the experiments. Three out of four animals survived for the scheduled 30-day period, and the blood pumps and membrane oxygenators both exhibited sufficient hydrodynamic performance and good antithrombogenicity, while one animal died of massive bleeding from the outflow cannulation site. The animals' plasma free hemoglobin had returned to within the normal range by 1 week after the surgical intervention, and their hemodynamic and biochemistry parameters remained within their normal ranges throughout the experiment. The explanted centrifugal blood pumps did not display any trace of thrombus formation. Based on the biocompatibility demonstrated in this study, the examined centrifugal blood pump, which includes a hydrodynamically levitated impeller, is suitable for use in durable ECMO systems. PMID:25975380

  4. Development of the Floating Centrifugal Pump by Use of Non Contact Magnetic Drive and Its Performance

    Directory of Open Access Journals (Sweden)

    Mitsuo Uno

    2004-01-01

    Full Text Available This article focuses on the impeller construction, non contact driving method and performance of a newly developed shaftless floating pump with centrifugal impeller. The drive principle of the floating impeller pump used the magnet induction method similar to the levitation theory of the linear motor. In order to reduce the axial thrust by the pressure different between shroud and disk side, the balance hole and the aileron blade were installed in the floating impeller. Considering the above effect, floating of an impeller in a pump was realized. Moreover, the performance curves of a developed pump are in agreement with a general centrifugal pump, and the dimensionless characteristic curve also agrees under the different rotational speed due to no mechanical friction of the rotational part. Therefore, utility of a non contacting magnetic-drive style pump with the floating impeller was made clear.

  5. Suppression of secondary flows in a double suction centrifugal pump with different loading distributions

    International Nuclear Information System (INIS)

    Secondary flow is one of the main reasons for low efficiency in double suction centrifugal pump. In a 3-D inverse design method, the pump blade could be designed by a specified loading distribution to control the flow field in pump. In order to study the influence of loading distribution on secondary flow of a double suction centrifugal pump, the external characteristics and the internal flow field of the pump with three kinds of loading distributions are analysed by using CFD approach. According to the simulation results, it is found that the form of fore-loading distribution at shroud and aft-loading distribution at hub could improve the optimal efficiency and broaden the high efficiency area of the pump. Furthermore, the secondary flow in impeller exit region and volute could be significantly suppressed if the slope of loading distribution curve of shroud is set to be −0.7

  6. Suppression of secondary flows in a double suction centrifugal pump with different loading distributions

    Science.gov (United States)

    Leng, H. F.; Wang, F. J.; Zhang, Z. C.; Yao, Z. F.; Zhou, P. J.

    2013-12-01

    Secondary flow is one of the main reasons for low efficiency in double suction centrifugal pump. In a 3-D inverse design method, the pump blade could be designed by a specified loading distribution to control the flow field in pump. In order to study the influence of loading distribution on secondary flow of a double suction centrifugal pump, the external characteristics and the internal flow field of the pump with three kinds of loading distributions are analysed by using CFD approach. According to the simulation results, it is found that the form of fore-loading distribution at shroud and aft-loading distribution at hub could improve the optimal efficiency and broaden the high efficiency area of the pump. Furthermore, the secondary flow in impeller exit region and volute could be significantly suppressed if the slope of loading distribution curve of shroud is set to be -0.7.

  7. Experimental Investigation and Passive Flow Control of a Cavitating Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Spyridon D. Kyparissis

    2012-01-01

    Full Text Available Passive flow control techniques are used to improve the flow field and efficiency of centrifugal pumps and turbomachines, in general. An important phenomenon that mechanical engineers have to take into account is cavitation. It leads to the decrease of the pump performance and total head. In the present experimental study, a centrifugal pump is investigated in cavitating conditions. A passive flow control is realized using three different blade leading edge angles in order to reduce the cavitation development and enhance the pump performance. The experiments are carried out in a pump test rig specially designed and constructed, along with the impellers. The head drop and total efficiency curves are presented in order to examine the effect of the blade leading edge angle on the cavitation and pump performance. Finally, the vapour distribution along with the blades is illustrated for the tested blade leading edge angles.

  8. Displacement Pumping of Liquids Radially Inward on Centrifugal Microfluidic Platforms in Motion

    Directory of Open Access Journals (Sweden)

    Eric D. Salin

    2011-12-01

    Full Text Available We describe two novel centrifugal microfluidic platform designs that enable passive pumping of liquids radially inward while the platform is in motion. The first design uses an immiscible liquid to displace an aqueous solution back towards the center of the platform, while the second design uses an arbitrary pumping liquid with a volume of air between it and the solution being pumped. Both designs demonstrated the ability to effectively pump 55% to 60% of the solution radially inward at rotational frequencies as low as 400 rpm (6.7 Hz to 700 rpm (11.7 Hz. The pumping operations reached completion within 120 s and 400 s respectively. These platform designs for passive pumping of liquids do not require moving parts or complex fabrication techniques. They offer great potential for increasing the number of sequential operations that can be performed on centrifugal microfluidic platforms, thereby reducing a fundamental limitation often associated with these platforms.

  9. Diagnosis of Centrifugal Pump Faults Using Vibration Methods

    OpenAIRE

    Albraik, A.; Al Thobiani, Faisal; Gu, Fengshou; Ball, Andrew

    2012-01-01

    Pumps are the largest single consumer of power in industry. This means that faulty pumps cause a high rate of energy loss with associated performance degradation, high vibration levels and significant noise radiation. This paper investigates the correlations between pump performance parameters including head, flow rate and energy consumption and surface vibration for the purpose of both pump condition monitoring and performance assessment. Using an in-house pump system, a number of experiment...

  10. Experimental study on cavitation in centrifugal pump impellers

    International Nuclear Information System (INIS)

    Investigations concerning cavitation in centrifugal impellers were carried out in a closed circuit. The value of net positive suction head (NPSH) at different head drops and at breakdown were used to verify the affinity laws

  11. Performance Optimization in a Centrifugal Pump Impeller by Orthogonal Experiment and Numerical Simulation

    OpenAIRE

    Ling Zhou; Weidong Shi; Suqing Wu

    2013-01-01

    In order to improve the hydrodynamic performance of the centrifugal pump, an orthogonal experiment was carried out to optimize the impeller design parameters. This study employs the commercial computational fluid dynamics (CFD) code to solve the Navier-Stokes equations for three-dimensional steady flow and predict the pump performance. The prototype experimental test results of the original pump were acquired and compared with the data predicted from the numerical simulation, which presents a...

  12. Hydrogen test of a small, low specific speed centrifugal pump stage

    Science.gov (United States)

    1991-01-01

    A small, low specific speed centrifugal pump stage with a 2 inch tip diameter, .030 inch tip width shrouded impeller and volute collector was tested with liquid hydrogen as the pumped fluid. The hydrodynamic design of the pump stage is summarized and the noncavitating and cavitating performance results are presented. Test speeds were 60 and 80 percent of the 77,000 rpm design speed. Liquid hydrogen test results are compared with data from previous tests of the stage in water.

  13. Response of a radial-bladed centrifugal pump to sinusoidal disturbances for noncavitating flow

    Science.gov (United States)

    Anderson, D. A.; Blade, R. J.; Stevans, W.

    1971-01-01

    A radial-bladed centrifugal pump was run in water with sinusoidal fluctuations of pressure and flow rate imposed at the pump inlet. Since the flow was noncavitating, zero gain was assumed in computing pump impedance. The inertive reactance became greater than the resistance at relatively low frequencies. An electric circuit model was developed in order to explain the trends of inertance and resistance with frequency.

  14. Numerical simulation of an axial blood pump.

    Science.gov (United States)

    Chua, Leok Poh; Su, Boyang; Lim, Tau Meng; Zhou, Tongming

    2007-07-01

    The axial blood pump with a magnetically suspended impeller is superior to other artificial blood pumps because of its small size. In this article, the distributions of velocity, path line, pressure, and shear stress in the straightener, the rotor, and the diffuser of the axial blood pump, as well as the gap zone were obtained using the commercial software, Fluent (version 6.2). The main focus was on the flow field of the blood pump. The numerical results showed that the axial blood pump could produce 5.14 L/min of blood at 100 mm Hg through the outlet when rotating at 11,000 rpm. However, there was a leakage flow of 1.06 L/min in the gap between the rotor cylinder and the pump housing, and thus the overall flow rate the impeller could generate was 6.2 L/min. The numerical results showed that 75% of the scalar shear stresses (SSs) were less than 250 Pa, and 10% were higher than 500 Pa within the whole pump. The high SS region appeared around the blade tip where a large variation of velocity direction and magnitude was found, which might be due to the steep angle variation at the blade tip. Because the exposure time of the blood cell at the high SS region within the pump was relatively short, it might not cause serious damage to the blood cells, but the improvement of blade profile should be considered in the future design of the axial pump. PMID:17584481

  15. Liquid helium centrifugal pump characteristics from 80 g/s to 1200 g/s

    CERN Document Server

    Pengo, R; Junker, S

    2010-01-01

    The large amount of data collected from three different centrifugal liquid helium pumps tested, namely with 80, 600 and 1200 g/s nominal mass flow are reviewed. The data include the analysis of the characteristic curves, their total efficiencies, their Net Positive Suction Head (NPSH) and the slip factor. The 1200 g/s pumps tested are of the full emission type, with curved blades, whilst the other pumps have straight blades. The pumps were also tested at different rotary speeds. The pumps were manufactured by Barber \\& Nichols (Denver, USA). (C) 2009 Elsevier Ltd. All rights reserved.

  16. A Method to Determine the Slip Factor of Centrifugal Pumps through Experiment

    Science.gov (United States)

    Zhang, Yu-Liang; Zhu, Zu-Chao; Dou, Hua-Shu; Cui, Bao-Ling; Li, Yi; Xiao, Jun-Jian

    2015-04-01

    In this paper, a method to determine the slip factor of centrifugal impellers is proposed based on the experimental result of the external performance of centrifugal pumps. This proposed method is superior to the conventional experimental method, which needs not to measure the flow parameters at impeller outlet. The results show that the present method can be used to obtain the slip factor at offdesign condition in a wide range of flow rate besides at the design point.

  17. A New Method to Calculate Centrifugal Pump Performance Parameters for Industrial Oils

    Directory of Open Access Journals (Sweden)

    mohammad hassan shojaeefard

    2015-01-01

    Full Text Available Pumping of oil instead of water using centrifugal pumps causes rapid increase in the hydraulic losses which results significant reduction in head and efficiency. Therefore, deriving analytical methods to calculate variation of pump performance parameters versus working fluid viscosity is very important. In the present study, a novel method is proposed to calculate the head (H, efficiency ( and input power ( in P based on the loss analysis for pumps using industrial oils. A computer code is developed based on represented method and the results of this method are compared with experimental results for a centrifugal pump of type KWP KBloc65- 200. The results show good agreement between analytical and experimental methods. Finally, using such computer code, diagrams of head, efficiency and input power versus working fluid viscosity are plotted.The results show an interesting point known as “sudden rising head” which is observed experimentally and numerically in literatures.

  18. Influence of Prewhirl Regulation by Inlet Guide Vanes on Cavitation Performance of a Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Lei Tan

    2014-02-01

    Full Text Available The influence of prewhirl regulation by inlet guide vanes (IGVs on a centrifugal pump performance is investigated experimentally and numerically. The experimental results show that IGVs can obviously change the head and increase the efficiency of the tested centrifugal pump over a wide range of flow rates. Although the cavitation performance is degraded, the variation of the cavitation critical point is less than 0.5 m. Movement of the computed three-dimensional streamlines in suction pipe and impeller are analyzed in order to reveal the mechanism how the IGVs realize the prewhirl regulation. The calculated results show that the influence of IGVs on the cavitation performance of centrifugal pump is limited by a maximum total pressure drop of 1777 Pa, about 7.6% of the total pressure at the suction pipe inlet for a prewhirl angle of 24°.

  19. HYDRODYNAMIC OPTIMIZATION DESIGN OF LOW SOLIDITY VANED DIFFUSER FOR A CENTRIFUGAL PUMP USING GENETIC ALGORITHMS

    Institute of Scientific and Technical Information of China (English)

    LI Jun; FENG Zhen-ping; TSUKAMOTO Hiroshi

    2004-01-01

    This paper presents a hydrodynamic redesign of the conventional vaned diffuser into the low solidity vaned diffuser for the maximum static pressure recovery in a centrifugal pump. A Bezier curve representation for profile description was coupled with a blade-to-blade flow calculation and a real-coded genetic algorithm. A low solidity vaned diffuser of 0.89 in solidity was obtained through the present optimum design. Numerical analysis and experimental test were made to evaluate the hydrodynamic performance of the centrifugal pump with the designed low solidity vaned diffuser and original vaned diffuser. The obtained results demonstrate that the centrifugal pump with the optimized vaned diffuser has compact size compared with the original one while the performance requirements have been met.

  20. A modal approach for vibration analysis and condition monitoring of a centrifugal pump

    Directory of Open Access Journals (Sweden)

    Ramana Podugu

    2011-08-01

    Full Text Available The modal analysis of the centrifugal pump and its assembly is performed using FEM technology. The mathematical model and FEA model are built for the original centrifugal casing and simulation is made to find the pump natural frequencies. The first ten natural frequencies were compared to pump operating speed and their multiples up to pump vane passing frequency as per HIS (Hydraulic Institute Standards -9.6.4-2000 guidelines. In the original design, the first natural frequency in vertical direction of the pump is found to be thecause for resonance at the first multiple speed of the pump. The first natural frequency of the original model was found to be 63.25 Hz which is very close to 62.5 Hz of the pump operating speed by a margin of 1.2%. As per HIS clause 9.6.4.4, the first natural frequency should be 10% above or below the pump operating speed. Finally, the model was modified by stiffening the pump pedestals and again FEA analysis was carried out to find the natural frequencies. As a result of modification in design, the first natural frequency was increased to 74.31Hz which is above 10% the pump operating speed i.e., 62.5 Hz. Hence, the results of the modified design aresatisfied with HIS clause. The results also show that the higher the stiffness of the pump, higher the natural frequency is.

  1. Open-cycle centrifugal vapor-compression heat pump

    Science.gov (United States)

    Burgmeier, L. R.; Horner, J. E.

    1987-11-01

    The objectives of the program were: (1) to develop an open cycle, high lift, centrifugal steam compressor system that can be efficiently retrofitted to existing multi-effect and high temperature differential evaporators while maintaining the cost benefits of a single stage centrifugal compressor, and (2) to demonstrate the energy saving cost benefits of driving the compressor with a natural gas fueled gas turbine engine. The turbine exhaust was to be used for final drying of the product that was evaporated. The installation of the system is described along with the test activities through May 1987.

  2. Determination of Wear That Can be Formed at the Stainless Steel Wheels of the Centrifuge Pumps Used at Agricultural Irrigation

    OpenAIRE

    Yuksel, E; B. Eker

    2009-01-01

    The extent of this work is operating characteristics of a horizontal shafted centrifugal pump (which has stainless steel wheel) which has been operated for 7 hours on the average. A closed circuit pump system (circulating within itself) which was formed by attaching a horizontal shafted centrifugal pump which can be used in irrigation applications with a drum has been operated for 150 hours at laboratory conditions. To define the operating properties of the pump, its operating characteristics...

  3. Application of energy gradient theory in flow instability in a centrifugal pump

    International Nuclear Information System (INIS)

    The flow instability in a centrifugal pump is studied using the energy gradient theory. Since the Re is high, the base flow is assumed to be turbulent. The distribution of the energy gradient function K at various flow rates is obtained from numerical simulations. According to the energy gradient method, the area with larger value of K is the place to cause instability and to be of high turbulence intensity. The results show that instability is easier to be excited in the area of impeller outlet and volute tongue. In order to improve the stability of centrifugal pumps working under low flow rate condition, carefulness must be taken in these two key areas

  4. Defect diagnosis and root cause analysis for thrust roller bearing of centrifugal charging pump

    International Nuclear Information System (INIS)

    The centrifugal charging pump is one of the most important equipment for Nuclear power plant which requires very high reliability, during C9 fuel-cycle, the continuous high level vibration alarm happened on the centrifugal charging pump B, we diagnosed its faults correctly and selected the right operation mode and right time to dismantle it which ensure the safety and economic benefits of Nuclear power plant, and through deeply analysis the root causes of thrust bearing defaults, we can learn much from it especially for the diagnosis and analysis to the bearing faults which is common for rotating equipment. (author)

  5. Cavitation performance and flow characteristic in a centrifugal pump with inlet guide vanes

    Science.gov (United States)

    Tan, L.; Zha, L.; Cao, S. L.; Wang, Y. C.; Gui, S. B.

    2015-01-01

    The influence of prewhirl regulation by inlet guide vanes (IGVs) on cavitation performance and flow characteristic in a centrifugal pump is investigated. At the impeller inlet, the streamlines are regulated by the IGVs, and the axial velocity distribution is also influenced by the IGVs. Due to the total pressure loss on the IGVs, the cavitation performance of the centrifugal pump degrades. The cavitation area in impeller with IGVs is larger than one without IGVs. The specify values of total pressure loss between the suction pipe inlet and impeller inlet for three cavitation conditions show that the IGVs will generate additional pressure loss, which is related to the IGVs angles and cavitation conditions.

  6. Numerical simulation and analysis of cavitation flows in a double suction centrifugal pump

    Science.gov (United States)

    Meng, G.; Tan, L.; Cao, S. L.; Jian, W.; Liu, W. W.; Jiang, D. J.

    2015-01-01

    Cavitation is an unsteady phenomenon, which is nearly inevitable in pumps. It would degrade the pump performance, generate vibrations and noises, and even erode pump flow passage components. The double suction centrifugal pump at design flow rate and large flow rate is numerically simulated using the k-ω turbulence model and the mass transport cavitation model. As a result, the calculated variation of pump head with pump inlet pressure agreed well with the experimental data. The results demonstrate that the numerical model and method can accurately predict the cavitation flows in a double suction centrifugal pump. The cavitation characteristics are analysed in great details. In addition, based on the calculation results, the reason that the plunge of pump head curve is revealed. It is found that the steep fall of pump head happens when the cavity reaches the blade to blade throat and the micro-vortex group appears at the back of the blade suction side. At the same time, this practice can provide guidance for the optimal design of double suction pumps.

  7. A concept for improving efficiency of multistage centrifugal pumps

    Science.gov (United States)

    Gardy, H. F.

    1970-01-01

    Multichannel impeller consists of successive stage impellers arranged concentrically without clearances between them. Reduction in friction is predicted to increase pump efficiency by 5 to 10 percent.

  8. Experimental testing of centrifugal pump: small and medium sized enterprise product

    Science.gov (United States)

    Ismail, R.; Paddiyatu, F.; Khafidh, M.; Nugroho, S.; Sugiyanto, S.; Jamari, J.

    2014-06-01

    This paper reports the experimental testing for centrifugal pump for fisherman ship, manufactured by small and medium sized enterprises in Central Java Province, Indonesia. The research covers material analysis, component observation, endurance and vibration test. Six centrifugal pumps are tested and three main pump components are discussed: shaft, bearings and seals. The results show that the material of the shaft is predicted to support and transmit the load from the engine to impeller. The problem found in the tolerance and geometry accuracy of the shaft which causes difficulties during assembling process, excessive wear and leakage during testing. From the endurance and vibration test, the ball bearings fail and lock the shaft due to the fatigue on the rolling elements and raceways. The oil seal and water seal also fail in maintaining the oil and water in the chamber and induce the unlubricated system for the ball bearings. Some suggestions are delivered to improve the product quality of the centrifugal pump. A good quality of the centrifugal pump for fishermen ship and long life span is expected to be produced by local SMEs to win the free trade competition in the Indonesian market.

  9. Optimization and Analysis of Centrifugal Pump considering Fluid-Structure Interaction

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2014-01-01

    Full Text Available This paper presents the optimization of vibrations of centrifugal pump considering fluid-structure interaction (FSI. A set of centrifugal pumps with various blade shapes were studied using FSI method, in order to investigate the transient vibration performance. The Kriging model, based on the results of the FSI simulations, was established to approximate the relationship between the geometrical parameters of pump impeller and the root mean square (RMS values of the displacement response at the pump bearing block. Hence, multi-island genetic algorithm (MIGA has been implemented to minimize the RMS value of the impeller displacement. A prototype of centrifugal pump has been manufactured and an experimental validation of the optimization results has been carried out. The comparison among results of Kriging surrogate model, FSI simulation, and experimental test showed a good consistency of the three approaches. Finally, the transient mechanical behavior of pump impeller has been investigated using FSI method based on the optimized geometry parameters of pump impeller.

  10. Investigation of Flow Through Centrifugal Pump Impellers Using Computational Fluid Dynamics

    OpenAIRE

    Zhou W.; Zhao Z; Lee S. T.; Winoto H. S.

    2003-01-01

    With the aid of computational fluid dynamics, the complex internal flows in water pump impellers can be well predicted, thus facilitating the design of pumps. This article describes the three-dimensional simulation of internal flow in three different types of centrifugal pumps (one pump has four straight blades and the other two have six twisted blades). A commercial three-dimensional Navier-Stokes code called CFX, with a standard k–ε two-equation turbulence model was used to simulate the pro...

  11. Research on the noise induced by cavitation under the asymmetric cavitation condition in a centrifugal pump

    Science.gov (United States)

    Lu, J. X.; Yuan, S. Q.; Yuan, J. P.; Ren, X. D.; Pei, J.; Si, Q. R.

    2015-12-01

    An experimental investigation has been carried out to research the noise induced by cavitation under the asymmetric cavitation (AC) condition in a centrifugal pump. The acoustic pressure signals at the pump inlet and outlet were measured respectively during the development of cavitation in a closed hydraulic test rig. It could be found that both the pump inlet and outlet acoustic pressures changed obviously with the development of cavitation. The time domain and the power spectrum density of the pump inlet and outlet acoustic pressure pulsations were analyzed. The broadband pulses of the acoustic pressure pulsations were found and the reasons for the phenomenon were given.

  12. Characteristics of centrifugal pumps handling air-water mixtures and size of air bubbles in pump impellers

    International Nuclear Information System (INIS)

    Characteristics of centrifugal pumps handling air-water mixtures are analyzed on the basis of a gas-liquid separated flow model, which is generally accepted in the analysis of the data on a two-phase flow in piping systems. And a method for predicting the pump characteristics is presented with use of parameters of friction-loss and shock-loss multipliers. Size of air bubbles flowing through pump impellers was measured. The bubbles in the inlet region of the impellers have an extremely uniform size with fairly small diameters. But in course of flow, the bubble diameter grows gradually due to coalescence of the bubbles. (author)

  13. Platelet function during cardiopulmonary bypass using multiple electrode aggregometry: comparison of centrifugal and roller pumps.

    Science.gov (United States)

    Kehara, Hiromu; Takano, Tamaki; Ohashi, Noburo; Terasaki, Takamitsu; Amano, Jun

    2014-11-01

    Blood trauma may be lower with centrifugal pumps (CPs) than with roller pumps (RPs) during cardiopulmonary bypass (CPB), because, unlike RPs, CPs do not compress the tubing, and shear stress is considered lower in CPs than in RPs. However, relative platelet function remains unclear. Using multiple electrode aggregometry (MEA), we compared platelet function with CP and RP. Ten swine underwent CPB for 3 h, with five weaned off using CP and five using RP. Platelet function was measured using MEA, as were hemoglobin concentration and platelet count, before sternotomy, after heparin infusion, 30 min and 3 h after starting CPB, after protamine infusion, and 60 min after stopping CPB. Platelet activation was initiated with adenosine diphosphate (ADP), arachidonic acid (AA), and thrombin receptor-activating protein 6 (TRAP). Fibrinogen, platelet factor 4 (PF4), and β-thromboglobin (β-TG) concentrations were measured before sternotomy and 60 min after stopping CPB. In the CP group and using ADP, aggregation was significantly reduced 30 min (P = 0.019) and 3 h (P = 0.027) after starting CPB, recovering to baseline 60 min after CPB was stopped. In the RP group, aggregation was significantly decreased 30 min (P = 0.007) and 3 h (P = 0.003) after starting CPB and after protamine administration (P = 0.028). With AA, aggregation significantly decreased 30 min after starting CPB in both the CP (P = 0.012) and RP (P = 0.016) groups, slightly increasing 3 h after starting CPB and after protamine infusion, and recovering to baseline 60 min after CPB cessation. With TRAP, aggregation in the CP and RP groups decreased 30 min after starting the pump, although changes were not significant; aggregation gradually recovered after 3 h and returned to baseline 60 min after the pumps were stopped. There were no significant differences at all sampling points of MEA. In both groups, fibrinogen, PF4, and β-TG concentrations were similar 60 min after pump cessation and before sternotomy

  14. Application of two turbulence models for computation of cavitating flows in a centrifugal pump

    International Nuclear Information System (INIS)

    To seek a better numerical method to simulate the cavitating flow field in a centrifugal pump, the applications between RNG k- ε and LES turbulence model were compared by using the Zwart-Gerber-Belamri cavitation model. It was found that both the models give almost the same results with respect to pump performance and cavitation evolutions including growth, local contraction, stability and separation in the impeller passage. But the LES model can not only capture the pump suction recirculation and the low frequency fluctuation caused by it, but also combine the changes of the shaft frequency amplitude acting on the impeller with the cavitation unstable characteristics. Thus the LES model has more advantages than RNG k- ε model in calculating the unsteady cavitating flow in a centrifugal pump

  15. Hydraulic performance of a low specific speed centrifugal pump with Spanwise-Slotted Blades

    International Nuclear Information System (INIS)

    The hydraulic efficiency of a low specific speed centrifugal pump is low because of the long and narrow meridian flow passage, and the severe disk friction. Spanwise slotted blade flow control technology has been applied to the low specific speed centrifugal pump. This paper concluded that spanwise slotted blades can improve the pump performance in both experiments and simulations. In order to study the influence to the impeller and volute by spanwise slotted blade, impeller efficiency and volute efficiency were defined. The minimum volute efficiency and the maximum pump efficiency appear at the same time in the design flow condition in the unsteady simulation. The mechanism of spanwise slotted blade flow control technology should be researched furthermore

  16. Hydraulic performance of a low specific speed centrifugal pump with Spanwise-Slotted Blades

    Science.gov (United States)

    Ye, D. X.; Li, H.; Wang, Y.

    2013-12-01

    The hydraulic efficiency of a low specific speed centrifugal pump is low because of the long and narrow meridian flow passage, and the severe disk friction. Spanwise slotted blade flow control technology has been applied to the low specific speed centrifugal pump. This paper concluded that spanwise slotted blades can improve the pump performance in both experiments and simulations. In order to study the influence to the impeller and volute by spanwise slotted blade, impeller efficiency and volute efficiency were defined. The minimum volute efficiency and the maximum pump efficiency appear at the same time in the design flow condition in the unsteady simulation. The mechanism of spanwise slotted blade flow control technology should be researched furthermore.

  17. NUMERICAL SIMULATION OF THE FLOW IN THE CENTRIFUGAL PUMP WITHIN VANE AND VANELESS DIFFUSER

    Directory of Open Access Journals (Sweden)

    K. Melih GÜLEREN

    2004-03-01

    Full Text Available In this study, the flow in a 5-bladed centrifugal pump within vaned and vaneless diffuser is analyzed numerically. The method contains of assumption as steady, incompressible and viscous flow solved according to 2-D Navier-Stokes equations relating finite volume technique. The pump used in this study runs at 890 rpm, its impeller diameter is approximately 20 cm and it has back-swept blade geometry. The jet-wake flow structures within the impeller and diffuser passages are investigated elaborately and in addition to this, the effects of vaned and vaneless diffuser of the pump are analyzed. The results are shown as velocity vectors, pressure and turbulent kinetic energy distributions in centrifugal pump, beside the performance curves. Moreover, the results are compared with available experimental data which is seen good agreement.

  18. Application of two turbulence models for computation of cavitating flows in a centrifugal pump

    Science.gov (United States)

    He, M.; Guo, Q.; Zhou, L. J.; Wang, Z. W.; Wang, X.

    2013-12-01

    To seek a better numerical method to simulate the cavitating flow field in a centrifugal pump, the applications between RNG k- ε and LES turbulence model were compared by using the Zwart-Gerber-Belamri cavitation model. It was found that both the models give almost the same results with respect to pump performance and cavitation evolutions including growth, local contraction, stability and separation in the impeller passage. But the LES model can not only capture the pump suction recirculation and the low frequency fluctuation caused by it, but also combine the changes of the shaft frequency amplitude acting on the impeller with the cavitation unstable characteristics. Thus the LES model has more advantages than RNG k- ε model in calculating the unsteady cavitating flow in a centrifugal pump.

  19. Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

    Directory of Open Access Journals (Sweden)

    Babayigit Osman

    2015-01-01

    Full Text Available Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics software for constant width impeller entrance and exit gates, blade numbers and blade thickness. Firstly, the flow volume of a centrifugal pump impeller is generated and then mesh structure is formed for the full impeller flow volume. Secondly, rotational periodic flow model are adopted in order to examine the effect of periodic flow assumption on the performance predictions. Corresponding to the available experimental data, inlet mass flow rate, outlet static pressure and rotation of impeller are taken as 0.02m3s-1, 450 kPa and 2950 rpm, respectively for the water fluid. No slip boundary condition is exposed to all solid of surface in the flow volume. The continuity and Navier-Stokes equations with the k-ε turbulence model and the standard wall functions are used. During the study, numerical analyses are conducted for the blade exit angle values of 18°, 20°, 25°, 30° and 35°. In consequence of the performed analyses, it is determined that hydraulic efficiency of the pump impeller value is changed between 81.0-84.6%. The most convenient blade exit angle that yields 84.6% hydraulic efficiency at is 18°. The obtained results show that the blade exit angle range has an impact on the centrifugal pump performance describing the pump head and the hydraulic efficiency.

  20. Numerical Investigation of Periodically Unsteady Pressure Field in a High Power Centrifugal Diffuser Pump

    OpenAIRE

    Ji Pei; Wenjie Wang; Shouqi Yuan; Jieyun Mao

    2014-01-01

    Pressure fluctuations are the main factors that can give rise to reliability problems in centrifugal pumps. The periodically unsteady pressure characteristics caused by rotor-stator interaction have been investigated by CFD calculation in a residual heat removal pump. Side chamber flow effect is also considered for the simulation to accurately predict the flow in whole flow passage. The pressure fluctuation results in time and frequency domains were considered for several typical monitoring p...

  1. CFD analysis and redesign of centrifugal impeller flows for rocket pumps

    OpenAIRE

    Lupi, Alessandro

    1993-01-01

    The analysis and redesign of a centrifugal impeller for a rocket pump is presented in this thesis. A baseline impeller was designed by Rocketdyne for the NASA Marshall Pump Consortium. Initially, the objective was to reduce the circumferential exit flow distortion of the baseline impeller. Later in the study, the objective became raising the head coefficient of the impeller. The study presented in this thesis was also undertaken to demonstrate current CFD capabilities for im...

  2. The Effect of Inlet Swirl on the Rotordynamic Shroud Forces in a Centrifugal Pump

    OpenAIRE

    Guinzburg, A.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1992-01-01

    The role played by fluid forces in determining the rotordynamic stability of a centrifugal pump is gaining increasing attention. The present research investigates the contributions to the rotordynamic forces from the discharge-to-suction leakage flows between the front shroud of the rotating impeller and the stationary pump casing. In particular, the dependency of the rotordynamic characteristics of leakage flows on the swirl at the inlet to the leakage path was examined. An inlet guide va...

  3. Numerical identification of blade exit angle effect on the performance for a multistage centrifugal pump impeller

    Science.gov (United States)

    Babayigit, Osman; Kocaaslan, Osman; Hilmi Aksoy, Muharrem; Melih Guleren, Kursad; Ozgoren, Muammer

    2015-05-01

    Nowadays, single and multistage centrifugal pumps are widely used in industrial and mining enterprises. One of the most important components of a centrifugal pump is the impeller. The performance characteristics are related to the pump comprising the head and the overall efficiency rely a great deal on the impeller geometry. In this work, effects of blade exit angle change on hydraulic efficiency of a multi stage pump impeller are investigated via Ansys-Fluent computational fluid dynamics software for constant width impeller entrance and exit gates, blade numbers and blade thickness. Firstly, the flow volume of a centrifugal pump impeller is generated and then mesh structure is formed for the full impeller flow volume. Secondly, rotational periodic flow model are adopted in order to examine the effect of periodic flow assumption on the performance predictions. Corresponding to the available experimental data, inlet mass flow rate, outlet static pressure and rotation of impeller are taken as 0.02m3s-1, 450 kPa and 2950 rpm, respectively for the water fluid. No slip boundary condition is exposed to all solid of surface in the flow volume. The continuity and Navier-Stokes equations with the k-ɛ turbulence model and the standard wall functions are used. During the study, numerical analyses are conducted for the blade exit angle values of 18°, 20°, 25°, 30° and 35°. In consequence of the performed analyses, it is determined that hydraulic efficiency of the pump impeller value is changed between 81.0-84.6%. The most convenient blade exit angle that yields 84.6% hydraulic efficiency at is 18°. The obtained results show that the blade exit angle range has an impact on the centrifugal pump performance describing the pump head and the hydraulic efficiency.

  4. Model based fault diagnosis in a centrifugal pump application using structural analysis

    DEFF Research Database (Denmark)

    Kallesøe, C. S.; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik;

    2004-01-01

    A model based approach for fault detection and isolation in a centrifugal pump is proposed in this paper. The fault detection algorithm is derived using a combination of structural analysis, Analytical Redundant Relations (ARR) and observer designs. Structural considerations on the system are used...... to an industrial benchmark. The benchmark tests have shown that the algorithm is capable of detection and isolation of five different faults in the mechanical and hydraulic parts of the pump....

  5. Investigation of CFD calculation method of a centrifugal pump with unshrouded impeller

    Science.gov (United States)

    Wu, Dazhuan; Yang, Shuai; Xu, Binjie; Liu, Qiaoling; Wu, Peng; Wang, Leqin

    2014-03-01

    Currently, relatively large errors are found in numerical results in some low-specific-speed centrifugal pumps with unshrouded impeller because the effect of clearances and holes are not accurately modeled. Establishing an accurate analytical model to improve performance prediction accuracy is therefore necessary. In this paper, a three-dimensional numerical simulation is conducted to predict the performance of a low-specific-speed centrifugal pump, and the modeling, numerical scheme, and turbulent selection methods are discussed. The pump performance is tested in a model pump test bench, and flow rate, head, power and efficiency of the pump are obtained. The effect of taking into consideration the back-out vane passage, clearance, and balance holes is analyzed by comparing it with experimental results, and the performance prediction methods are validated by experiments. The analysis results show that the pump performance can be accurately predicted by the improved method. Ignoring the back-out vane passage in the calculation model of unshrouded impeller is found to generate better numerical results. Further, the calculation model with the clearances and balance holes can obviously enhance the numerical accuracy. The application of disconnect interface can reduce meshing difficulty but increase the calculation error at the off-design operating point at the same time. Compared with the standard k-ɛ, renormalization group k-ɛ, and Spalart-Allmars models, the Realizable k-ɛ model demonstrates the fastest convergent speed and the highest precision for the unshrouded impeller flow simulation. The proposed modeling and numerical simulation methods can improve the performance prediction accuracy of the low-specific-speed centrifugal pumps, and the modeling method is especially suitable for the centrifugal pump with unshrouded impeller.

  6. End Suction Centrifugal Pump Operating in Turbine Mode for Microhydro Applications

    OpenAIRE

    Mohd Azlan Ismail; Al Khalid Othman; Shahidul Islam; Hushairi Zen

    2014-01-01

    This paper reviews the current research works on the end suction centrifugal pump coupled with induction generator running in turbine mode for microhydro application. The information can be used by practicing engineers, researchers, and plant managers to understand the potential of pump running as turbine. Review on experimental and simulation works was carried out encompassing end suction single stage low specific speed which is less than 10 kW. This is followed by review of their efficiency...

  7. A New Proposed Return Guide Vane for Compact Multistage Centrifugal Pumps

    OpenAIRE

    Qihua Zhang; Weidong Shi; Yan Xu; Xiongfa Gao; Chuan Wang; Weigang Lu; Dongqi Ma

    2013-01-01

    For widely used multistage centrifugal pumps, their former structures are so bulky that nowadays growing interest has been shifted to the development of more compact structures. Following this trend, a compact pump structure is provided and analysed. To maintain the pump’s pressure recovery, as well as to meet the water flow from the impeller, a circumferential twisted return guide vane (RGV) is proposed. To validate this design method, the instantaneous CFD simulations are performed to inves...

  8. Model Based Fault Diagnosis in a Centrifugal Pump Application using Structural Analysis

    DEFF Research Database (Denmark)

    Kallesøe, C. S.; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik;

    2004-01-01

    A model based approach for fault detection and isolation in a centrifugal pump is proposed in this paper. The fault detection algorithm is derived using a combination of structural analysis, Analytical Redundant Relations (ARR) and observer designs. Structural considerations on the system are used...... to an industrial benchmark. The benchmark tests have shown that the algorithm is capable of detection and isolation of five different faults in the mechanical and hydraulic parts of the pump....

  9. Development of the Floating Centrifugal Pump by Use of Non Contact Magnetic Drive and Its Performance

    OpenAIRE

    Mitsuo Uno; Takaaki Masuzoe; Isamu Aotani; Shin Oba; Toshiaki Kanemoto

    2004-01-01

    This article focuses on the impeller construction, non contact driving method and performance of a newly developed shaftless floating pump with centrifugal impeller. The drive principle of the floating impeller pump used the magnet induction method similar to the levitation theory of the linear motor. In order to reduce the axial thrust by the pressure different between shroud and disk side, the balance hole and the aileron blade were installed in the floating impeller. Considering the above ...

  10. Influence of Splitter Blades on the Cavitation Performance of a Double Suction Centrifugal Pump

    OpenAIRE

    Wei Yang; Ruofu Xiao; Fujun Wang; Yulin Wu

    2014-01-01

    In order to study the influence of splitter blades on double suction centrifugal pumps two impellers with and without splitter blades were investigated numerically and experimentally. Three-dimensional turbulence simulations with and without full cavitation model were applied to simulate the flow in the two pumps with different impellers. The simulation results agreed with the experiment results and the internal flows were analyzed. Both the numerical and experimental results show that by add...

  11. Experimental and Numerical Investigation of Radial Forces Acting on Centrifugal Pump Impeller

    OpenAIRE

    Karaskiewicz Krzysztof; Szlaga Marek

    2014-01-01

    The paper presents the results of measurements and predictions of radial thrust in centrifugal pump with specific speed ns = 26. In the pump tested, a volute with rectangular cross-section was used. The tests were carried out for several rotational speeds, including speeds above and below the nominal one. Commercial code ANSYS Fluent was used for the calculations. Apart from the predictions of the radial force, the calculations of axial thrust were also conducted, and correlation between thru...

  12. Numerical analysis of the flow field in the pump chamber of a centrifugal pump with back blades

    International Nuclear Information System (INIS)

    Black blade is frequently used as a non-contact seal structure in centrifugal pumps transporting solid-liquid two-phase flow. However, it will disturb the flow in the pump and affect the pump performance. Numerical simulation for 3D turbulence in whole flow passage of a centrifugal pump with back blades was carried out based on RANS method, with SST k-ω turbulence model and SIMPLEC algorithm. Calculation for a similar pump without back blades was also carried out as a comparison. Boundary condition was improved due to the existence of back blade. The influence of back blades on the flow field was analysed qualitatively for three typical conditions. Meanwhile the leakage rate was calculated for several conditions and the effect of back blades was discussed. According to the results, compared with the condition without back blades, it could be seen that back blade apparently changed the flow state in the front chamber, improved near the front shroud and worsened near the pump cover. Velocity was increased and more fluid, which flowed into the front chamber from the pump cover side, flowed back to the spiral casing from the impeller shroud side. With the increase of discharge, the absolute value of leakage rate first went up and then dropped, as a consequence of the combination of two factors, discharge and differential pressure between the impeller outlet and inlet. The seal effect of back blades is most obvious under small discharge condition, and the leakage loss diminished as discharge increased

  13. Numerical analysis of the flow field in the pump chamber of a centrifugal pump with back blades

    Science.gov (United States)

    Cao, L.; Wang, Z. W.; Y Luo, Y.; Liu, M.

    2013-12-01

    Black blade is frequently used as a non-contact seal structure in centrifugal pumps transporting solid-liquid two-phase flow. However, it will disturb the flow in the pump and affect the pump performance. Numerical simulation for 3D turbulence in whole flow passage of a centrifugal pump with back blades was carried out based on RANS method, with SST k-ω turbulence model and SIMPLEC algorithm. Calculation for a similar pump without back blades was also carried out as a comparison. Boundary condition was improved due to the existence of back blade. The influence of back blades on the flow field was analysed qualitatively for three typical conditions. Meanwhile the leakage rate was calculated for several conditions and the effect of back blades was discussed. According to the results, compared with the condition without back blades, it could be seen that back blade apparently changed the flow state in the front chamber, improved near the front shroud and worsened near the pump cover. Velocity was increased and more fluid, which flowed into the front chamber from the pump cover side, flowed back to the spiral casing from the impeller shroud side. With the increase of discharge, the absolute value of leakage rate first went up and then dropped, as a consequence of the combination of two factors, discharge and differential pressure between the impeller outlet and inlet. The seal effect of back blades is most obvious under small discharge condition, and the leakage loss diminished as discharge increased.

  14. Method of investigation of vibroacoustic characteristics of centrifugal pumps

    Science.gov (United States)

    Pokrovskiy, B. V.; Rubinov, V. Y.; Yurgin, A. M.

    1973-01-01

    A method for acoustical diagnostics of pumps is described which consists of taking sonograms of the pump, by means of an audio spectrograph. In distinction from usual analyzers, the spectrograph makes it possible to obtain a three-dimensional image of the signal being analyzed, in which its frequency-amplitude characteristics developed over time are depicted with a resolving power of 0.004 sec. As an example, a sonogram of an electrically driven pump, in the 40-4000 Hz frequency range, is presented. The amplitude ratios are determined on the sonogram by the contrast of individual contours, with an accuracy of 6 db.

  15. Experimental and numerical investigation of centrifugal pumps with asymmetric inflow conditions

    Science.gov (United States)

    Mittag, Sten; Gabi, Martin

    2015-11-01

    Most of the times pumps operate off best point states. Reasons are changes of operating conditions, modifications, pollution and wearout or erosion. As consequences non-rotational symmetric flows, transient operational conditions, increased risk of cavitation, decrease of efficiency and unpredictable wearout can appear. Especially construction components of centrifugal pumps, in particular intake elbows, contribute to this matter. Intake elbows causes additional losses and secondary flows, hence non-rotational velocity distributions as intake profile to the centrifugal pump. As a result the impeller vanes experience permanent changes of the intake flow angle and with it transient flow conditions in the blade channels. This paper presents the first results of a project, experimentally and numerically investigating the consequences of non-rotational inflow to leading edge flow conditions of a centrifugal pump. Therefore two pumpintake- elbow systems are compared, by only altering the intake elbow geometry: a common single bended 90° elbow and a numerically optimized elbow (improved regarding rotational symmetric inflow conditions and friction coefficient). The experiments are carried out, using time resolved stereoscopic PIV on a full acrylic pump with refractions index matched (RIM) working fluid. This allows transient investigations of the flow field simultaneously for all blade leading edges. Additional CFD results are validated and used to further support the investigation i.e. for comparing an analog pump system with ideal inflow conditions.

  16. Hydraulic design and pre-whirl regulation law of inlet guide vane for centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new hydraulic design method of three-dimensional guide vane for centrifugal pump is proposed on the assumption that the fluid at the outlet of guide vane satisfies the uniform velocity moment condition.The geometry of blade is controlled by the distributed rule of blade angles along the meridional streamline which is described by a fourth-order polynomial.Experiment results demonstrate that the designed guide vane can overcome the drawback of two-dimensional guide vane,enlarge the high efficiency scope and improve the hydraulic performance of centrifugal pump on the off-design operation conditions.In comparison with the performance of the centrifugal pump without inlet guide vane,the peak value of efficiency can be enhanced by 2.13% after the three-dimensional guide vane was being installed.The three-dimensional entire flow field of the centrifugal pump with inlet guide vane is simulated,and the basic principle and mechanism of inlet guide vane pre-whirl regulation are analyzed.The validity of design method has been proved.

  17. Numerical investigation of nonlinear vibration for rotor-seal system of centrifugal pump

    International Nuclear Information System (INIS)

    The exciting force in the seal is an important factor for the stability of a multiple stage centrifugal pump. With the speed increasing, the rotor system of multiple stage centrifugal pump presents some nonlinear characters. In order to provide supports for the research of nonlinear characters of multiple stage centrifugal pump, a rotor-seal system model of centrifugal pump is presented and the Muszynska nonlinear seal model is used to express the seal exciting force with multiple parameters in the paper. The fourth-order Runge-Kutta method is also used to determine the vibration response at the impeller place and obtain bifurcation diagram, axis orbit, phase diagram as well as Poincaré Map. The bifurcation results show that the rotor-seal system would be stable under a lower speed and change to be unstable as the rotor speed increases. Various multi-periodic motions and quasi-periodic motions are found showing the complicated motions in the rotor-seal system under nonlinear seal forces

  18. Root cause analysis of vibrations and pulsations in a naphtha pipe system with centrifugal pumps

    NARCIS (Netherlands)

    Bokhorst, E. van; Almasy, S.

    2010-01-01

    The capacity of a platform installation consisting of naphtha feed lines from centrifugal pumps to an oven has been increased by 25 % in combination with rerouting of the piping layout upstream of the oven and inside the convection zone. The operating company observed considerable increase of the vi

  19. Finite element calculations and experimental verification of the unsteady potential flow in a centrifugal volute pump

    NARCIS (Netherlands)

    Badie, R.; Jonker, J.B.; Braembussche, van den R.A.

    1994-01-01

    In this paper we present a finite-element-based methode for the calculation of the unsteady potential flow in rotor/stator configurations. A numerical algorithm was developed to calculate the two-dimensional flow through a centrifugal volute pump, taking into account the width variation of the volut

  20. PIV measurements and CFD computations of secondary flow in a centrifugal pump impeller

    NARCIS (Netherlands)

    Westra, R.W.; Broersma, L.; Andel, van K.; Kruyt, N.P.

    2010-01-01

    Two-dimensional particle image velocimetry measurements and three-dimensional computational fluid dynamics (CFD) analyses have been performed on the steady velocity field inside the shrouded impeller of a low specific-speed centrifugal pump operating with a vaneless diffuser. Flow rates ranging from

  1. CENTRIFUGE APPARATUS

    Science.gov (United States)

    Skarstrom, C.; Urey, H.C.; Cohen, K.

    1960-08-01

    A high-speed centrifuge for the separation of gaseous isotopes is designed comprising a centrifugal pump mounted on the outlet of a centrifuge bowl and arranged to pump the heavy and light fractions out of the centrifuge bowl in two separate streams.

  2. Study on cavitation in centrifugal sodium pumps for FBTR and PFBR

    International Nuclear Information System (INIS)

    Fast Breeder Test Reactor (FBTR) which is expected to become critical shortly is a loop type reactor of 40 MW thermal capacity and has two primary and two secondary centrifugal pumps for heat removal. During the initial periods of reactor operation, the steam generator is bypassed and the secondary sodium pumps are required to operate at flows less than that at best efficiency point. This paper deals with the cavitation problems associated with operation at partial f lows, theoretical estimations and experimental cavitation measurements carried out on FBTR secondary sodium pumps. These investigations revealed that operation of FBTR pumps at this off design condition is free from cavitation damage. Cavitation experiments on a model pump for the development of large sodium pumps for a 500 MWe Prototype Fast Breeder Reactor (PFBR) are described in this paper

  3. Influence of the empirical coefficients of cavitation model on predicting cavitating flow in the centrifugal pump

    Science.gov (United States)

    Liu, Hou-lin; Wang, Jian; Wang, Yong; Zhang, Hua; Huang, Haoqin

    2014-03-01

    The phenomenon of cavitation is an unsteady flow, which is nearly inevitable in pump. It would degrade the pump performance, produce vibration and noise and even damage the pump. Hence, to improve accuracy of the nu¬merical prediction of the pump cavitation performance is much desirable. In the present work, a homogenous model, the Zwart-Gerber-Belamri cavitation model, is considered to investigate the influence of the empirical coefficients on predicting the pump cavitation performance, concerning a centrifugal pump. Three coefficients are analyzed, namely the nucleation site radius, evaporation and condensation coefficients. Also, the experiments are carried out to validate the numerical simulations. The results indicate that, to get a precise prediction, the approaches of declining the initial bubble radius, the condensation coefficient or increasing the evaporation coefficient are all feasible, especially for de¬clining the condensation coefficient, which is the most effective way.

  4. A survey of instabilities within centrifugal pumps and concepts for improving the flow range of pumps in rocket engines

    Science.gov (United States)

    Veres, Joseph P.

    1992-01-01

    Design features and concepts that have primary influence on the stable operating flow range of propellant-feed centrifugal turbopumps in a rocket engine are discussed. One of the throttling limitations of a pump-fed rocket engine is the stable operating range of the pump. Several varieties of pump hydraulic instabilities are mentioned. Some pump design criteria are summarized and a qualitative correlation of key parameters to pump stall and surge are referenced. Some of the design criteria were taken from the literature on high pressure ratio centrifugal compressors. Therefore, these have yet to be validated for extending the stable operating flow range of high-head pumps. Casing treatment devices, dynamic fluid-damping plenums, backflow-stabilizing vanes and flow-reinjection techniques are summarized. A planned program was undertaken at LeRC to validate these concepts. Technologies developed by this program will be available for the design of turbopumps for advanced space rocket engines for use by NASA in future space missions where throttling is essential.

  5. A study on energy saving rate for variable speed condition of multistage centrifugal pump

    Science.gov (United States)

    Suh, Sang-Ho; Rakibuzzaman; Kim, Kyung-Wuk; Kim, Hyoung-Ho; Yoon, In Sik; Cho, Min-Tae

    2015-11-01

    Centrifugal pumps are being widely used in many industrial and commercial applications. Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations. The purpose of this study was to get the energy saving rates of the multistage centrifugal pump with variable speed conditions. For this investigation an experimental set up of variable flow and pressure system was made to get energy saving rates and numerical analyses are applied to validate the pump performance. The energy saving and therefore the cost saving depends on the specific duty cycle of which the machine operates. Duty cycle is the proportion of time during which a component, device and system is operated. The duty cycle segmented into different flow rates and weighting the average value for each segment by the interval time. The system was operated at 50% or less of the pump capacity. The input power of the system was carried out by pump characteristics curve of each operating point. The energy consumption was done by the product of specific duty cycle and the input power of the system for constant speed and variable speed drive operation. The total energy consumed for constant speed drive pump was 75,770 kW.hr and for variable speed drive pump was 31,700 kW.hr. The total energy saving of the system was 44,070 kW.hr or 58.16% annually. So, this paper suggests a method of implementing an energy saving on variable-flow and pressure system of the multistage centrifugal pump.

  6. Studies on the Influence of Various Blade Outlet Angles in a Centrifugal Pump when Handling Viscous Fluids

    OpenAIRE

    M. H.S. Fard; F. A. Boyaghchi

    2007-01-01

    In this study the centrifugal pump performances with different blade outlet angles are tested when handling water and viscous oils as Newtonian fluids. Also, this study shows a numerical simulation of the three-dimensional fluid flows inside the centrifugal pump with different blade outlet angles. For these numerical simulations the SIMPLEC algorithm is used for solving governing equations of incompressible viscous/turbulent flows through the pump at different operating conditions. The k-^...

  7. Numerical Analysis of Three-Dimensional Unsteady Turbulent Flow in Circular Casing of a High Power Centrifugal Diffuser Pump

    OpenAIRE

    Ji Pei; Shouqi Yuan; Wenjie Wang

    2013-01-01

    For high power centrifugal pump which is usually used in high risk applications, circular casing structure has been adopted to increase the reliability of the pump. This special casing structure can make the flow more complex and cause huge hydraulic losses. In this paper, the periodically unsteady turbulent flow in the circular casing of a high power centrifugal diffuser pump has been investigated numerically by CFD calculation. The velocity distributions in different positions were analyzed...

  8. The Impeller Improvement of the Centrifugal Pump Based on BVF Diagnostic Method

    OpenAIRE

    Xin Zhou; Yongxue Zhang; Zhongli Ji; Long Chen

    2014-01-01

    Selecting one IS 150-125-250 centrifugal pump as reference model, impeller with 3D blades has been designed using two-dimensional theory. Numerical simulations using Reynolds averaged N-S equations with a RNG k-ε two-equation turbulence model and log-law wall function are used to estimate the hydraulic performance of pump and obtain BVF distributions on impeller blade pressure surfaces and suction surfaces. The results show that, compared with IS150-125-250 pump, the designed one shows better...

  9. Performance of Very Low Specific Speed Centrifugal Pumps with Circular Casing

    OpenAIRE

    Kagawa, Shusaku; Kurokawa, Junichi; Matsui, Jun; Choi, Young-Do

    2007-01-01

    Efficiency of a centrifugal pump is known to drop rapidly with a decrease of specific speed ns in the range of ns ≦ 100 [m,m3/min,min-1]. However, below ns = 60, the pump efficiency is not yet clear, and the spiral angle of a volute casing becomes too small to manufacture. To solve this problem, a circular casing is considered appropriate in the very low ns range. The present study is aimed to reveal the relation between pump efficiency and a specific speed in the range of ns ≦ 60, when a cir...

  10. Flow in the Low Specific Speed Centrifugal Pump with Circular Casing

    OpenAIRE

    Matsui, Jun; Kurokawa, Junichi; Choi, Young-Do; Nishino, Kouichi

    2006-01-01

    The internal flow of a centrifugal pump with semi-open impeller, whose type-number is O.244, is measured by PIV method and analyzed numerically The head and efficiency of a pump that has a circular casing with a very small radius are almost same as those of the spiral casing. Even at the best efficiency point, the internal flow in the pump of circular casing is asymmetric. The flow goes out from the impeller only at the exhaust area of the casing. Also, there is a very strong unsteady flow ne...

  11. Performance of a small centrifugal pump in He I and He II

    Science.gov (United States)

    Ludtke, P. R.; Daney, D. E.; Steward, W. G.

    1988-01-01

    The performance characteristics of a small centrifugal pump in He I and He II are determined over the temperature range of 1.6 to 4.2 K. The single-stage pump is powered by a close-coupled cryogenic induction motor. In the absence of cavitation, pump performance (head and capacity) was found to be identical for He I and He II. Developed heads up to 16 m and capacities of up to 900 liters/hr are obtained at 7000 rpm. A three-blade screw inducer was shown to require much less suction head than a six-blade propeller inducer.

  12. Blade design loads on the flow exciting force in centrifugal pump

    Science.gov (United States)

    Xu, Y.; Yang, A. L.; Langand, D. P.; Dai, R.

    2012-11-01

    The three-dimensional viscous flow field of two centrifugal pumps, which have the same volute, design head, design flow rate and rotational speed but the blade design load, are analyzed based on large eddy simulation. The comparisons are implemented including the hydraulic efficiencies, flow field characteristics, pressure pulsations and unsteady forces applied on the impellers to investigate the effect of the design blade load on hydraulic performance and flow exciting force. The numerical results show that the efficiency of the pump, the impeller blade of which has larger design load, is improved by 1.1%~2.9% compared to the centrifugal pump with lower blade design load. The pressure fluctuation of the pump with high design load is more remarkable. Its maximum amplitude of coefficient of static pressure is higher by 43% than the latter. At the same time the amplitude of unsteady radial force is increased by 11.6% in the time domain. The results also imply that the blade design load is an important factor on the excitation force in centrifugal pumps.

  13. Effects of mesh style and grid convergence on numerical simulation accuracy of centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    刘厚林; 刘明明; 白羽; 董亮

    2015-01-01

    In order to evaluate the effects of mesh generation techniques and grid convergence on pump performance in centrifugal pump model, three widely used mesh styles including structured hexahedral, unstructured tetrahedral and hybrid prismatic/tetrahedral meshes were generated for a centrifugal pump model. And quantitative grid convergence was assessed based on a grid convergence index (GCI), which accounts for the degree of grid refinement. The structured, unstructured or hybrid meshes are found to have certain difference for velocity distributions in impeller with the change of grid cell number. And the simulation results have errors to different degrees compared with experimental data. The GCI-value for structured meshes calculated is lower than that for the unstructured and hybrid meshes. Meanwhile, the structured meshes are observed to get more vortexes in impeller passage. Nevertheless, the hybrid meshes are found to have larger low-velocity area at outlet and more secondary vortexes at a specified location than structured meshes and unstructured meshes.

  14. Unsteady diffuser vane pressure and impeller wake measurements in a centrifugal pump

    Science.gov (United States)

    Arndt, N.; Acosta, A. J.; Brennen, C. E.; Caughey, T. K.

    1987-01-01

    Unsteady surface pressure measurements on a vaned diffuser of a centrifugal pump, and wake measurements of the flow exiting a centrifugal impeller into a vaneless diffuser are presented. Frequency spectra and ensemble averages are given for the unsteady measurements. Two different impellers were used, the pump impeller of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine) and a two-dimensional impeller. The magnitude of the unsteady total pressure measured in the stationary frame at the impeller exit was found to be of the same order of magnitude as the total pressure rise across the pump. The magnitude of the unsteady diffuser vane pressures was observed to be significantly different on suction and pressure side of the vane, attaining its largest value on the suction side the leading edge while decreasing along the vane.

  15. Measurements for the rotordynamic shroud forces for centrifugal pumps

    OpenAIRE

    Guinzburg, A.; Brennen, C. E.; Acosta, A.J; Caughey, T. K.

    1990-01-01

    An experiment was designed to measure the rotordynamic shroud forces on a centrigual pump impeller. The measurements were doen for various whirl/impeller ratios and for different flow rates. A destabilising tangential force was measured for small positive whirl ratios and this force decreased with increasing flow rate.

  16. CENTRIFUGE

    Science.gov (United States)

    Rushing, F.C.

    1960-09-01

    A vibration damping mechanism for damping vibration forces occurring during the operation of a centrifuge is described. The vibration damping mechanism comprises a plurality of nested spaced cylindrical elements surrounding the rotating shaft of the centrifuge. Some of the elements are held substantially stationary while the others are held with respect to a pair of hearings spaced along the rotating shaft. A fluid is retained about the cylindrical elements.

  17. Variations in battery life of a heart-lung machine using different pump speeds, pressure loads, boot material, centrifugal pump head, multiple pump usage, and battery age.

    LENUS (Irish Health Repository)

    Marshall, Cornelius

    2012-02-03

    Electrical failure during cardiopulmonary bypass (CPB) has previously been reported to occur in 1 of every 1500 cases. Most heart-lung machine pump consoles are equipped with built-in battery back-up units. Battery run times of these devices are variable and have not been reported. Different conditions of use can extend battery life in the event of electrical failure. This study was designed to examine the run time of a fully charged battery under various conditions of pump speed, pressure loads, pump boot material, multiple pump usage, and battery life. Battery life using a centrifugal pump also was examined. The results of this study show that battery life is affected by pump speed, circuit pressure, boot stiffness, and the number of pumps in service. Centrifugal pumps also show a reduced drain on battery when compared with roller pumps. These elements affect the longevity and performance of the battery. This information could be of value to the individual during power failure as these are variables that can affect the battery life during such a challenging scenario.

  18. Design optimization of a centrifugal pump impeller and volute using computational fluid dynamics

    International Nuclear Information System (INIS)

    In this study, optimization of the impeller and design of volute were carried out in order to improve the performance of a centrifugal pump. Design parameters from vane plane development for impeller design were selected and effect of the design parameters on the performance of the pump was analyzed using CFD and Response Surface Method to optimized impeller. This study also proposed the optimization geometry of pump impeller for performance improvement through the results from numerical analysis that was obtained optimum design pump; efficiency 98.2% and head 64.5m. In addition, the pump design method was suggested by designing volute which was suitable for the optimized impeller through volute design where Stepanoff theory was applied and numerical analysis.

  19. Theoretical model for cavitation erosion prediction in centrifugal pump impeller

    International Nuclear Information System (INIS)

    Cavitation is known to have great effects on pump hydraulic and mechanical characteristics. These effects are mainly described by deviation in pump performance, increasing vibration and noise level as well as erosion of blade and casing materials. In the present work, only the hydrodynamic aspect of cavitation was considered. The efforts were directed toward the study of cavitation inception, cavity mechanics and material erosion in order to clarify the macrohydrodynamic aspects of cavitation erosive wear in real machines. As a result of this study, it was found that cavitation damage can be predicted from model data. The obtained theoretical results show good agreement with the experimental results obtained in this investigation and with results of some other investigations. The application of the findings of this work will help the design engineer in predicting the erosion rate, according to the different operating conditions. (author)

  20. Influence of Parameters of InductionMotor-Centrifugal Pump Units with Hydropaths Connected in Series on their Modes

    OpenAIRE

    Lysiak, Vladyslav

    2015-01-01

    Using the mathematical model of the pump station power supply system in steady-state modes developed by the author, the influence of the parameters of induction motor-centrifugal pump units with in-seriesconnected hydropaths of the pumps on their steady-state modes was studied. A comparison was drawn on the operation of a number of coupled units with different pump ratings. It was revealed that the difference in rated flow of the operating fluid in centrifugal pumps results in the fact that o...

  1. Cavitation improvement of double suction centrifugal pump HPP Fuhren

    Science.gov (United States)

    Škerlavaj, A.; Titzschkau, M.; Pavlin, R.; Vehar, F.; Mežnar, P.; Lipej, A.

    2012-11-01

    A double suction storage pump has been refurbished because of the strong cavitation which resulted in cavitation damage on blade and consequently in frequent repairs of the impeller. The analyses of the old and the new impeller were done by the computational fluid dynamics (CFD), performing transient simulations with the commercial solver Ansys CFX. In the simulations, the scale-adaptive-simulation with the curvature correction (SAS-CC) turbulence model was used. No model tests were carried out. Additionally, observations with the digital camera were made through the specially designed plexi-glass window, mounted at the lid at the suction side. The predicted pump head at the operating point agrees well with the pump characteristics measurements, performed with the direct thermodynamic method. The extent of the cavitation predicted by CFD is smaller than the observed one because the cloud cavitation was not predicted. The observations of the cavitation extent show that the impeller design is better than the old one, which was also possible to anticipate based on the CFD results.

  2. Vibration Characteristics Induced by Cavitation in a Centrifugal Pump with Slope Volute

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2015-01-01

    Full Text Available Cavitation is one of the instability sources in centrifugal pump, which would cause some unexpected results. The goal of this paper was to analyze the influence of cavitation process on different frequency bands in a centrifugal pump with slope volute. And special attention was paid to low frequency signals, which were often filtered in the reported researches. Results show that at noncavitation condition, vibration level is closely related to flow structure interior pump. At partial flow rates, especially low flow rates, vibration level increases rapidly with the onset of rotating stall. At cavitation condition, it is proved that cavitation process has a significant impact on low frequency signals. With cavitation number decreasing, vibration level first rises to a local maximum, then it drops to a local minimum, and finally it rises again. At different flow rates, vibration trends in variable frequency bands differ obviously. Critical point inferred from vibration level is much larger than that from 3% head drop, which indicates that cavitation occurs much earlier than that reflected in head curve. Also, it is noted that high frequency signals almost increase simultaneously with cavitation occurring, which can be used to detect cavitation in centrifugal pump.

  3. Unsteady flow characteristic of low-specific-speed centrifugal pump under different flow-rate conditions

    Science.gov (United States)

    Cui, Baoling; Chen, Desheng; Xu, Wenjing; Jin, Yingzi; Zhu, Zuchao

    2015-02-01

    To investigate the unsteady flow characteristics in centrifugal pump, the flow field in a low-specific-speed centrifugal pump with complex impeller is numerically simulated under different conditions. The RNG κ-ɛ turbulence model and sliding mesh are adopted during the process of computation. The results show that the interaction between impeller and volute results in the unstable flow of the fluid, which causes the uneven distribution of pressure fluctuations around the circumference of volute. Besides the main frequency and its multiple frequency of pressure fluctuations in the centrifugal pump, the frequency caused by the long blades of complex impeller also plays a dominant role in the low-frequency areas. Furthermore, there exists biggish fluctuation phenomenon near the tongue. The composition of static pressure fluctuations frequency on the volute wall and blade outlet is similar except that the fluctuation amplitude near the volute wall reduces. In general, the different flow rates mainly have influence on the amplitude of fluctuation frequency in the pump, while have little effect on the frequency composition.

  4. Rotordynamic forces generated by discharge-to-suction leakage flows in centrifugal pumps

    Institute of Scientific and Technical Information of China (English)

    LIU Quan-zhong; WANG Hong-jie; LIU Zhan-sheng

    2009-01-01

    In order to investigate the flow-induced vibration in the shroud passage of centrifugal pump and pre-dict rotordynamic forces of centrifugal pump rotor system,an analysis of rotordynamic forces arising from shrou-ded centnlugal pump is presented.CFD techniques were utilized to analyze the full three-dimensional viscous,primary/secondary flow field in a centrifugal pump impeller to determine rotordynamic forces. Multiple quasi-steady solutions of an eccentric three-dimensional model at different whirl frequency ratios yielded the rotordy-namic forces. The skew-symmetric stiffness,damping,and mass matrices were obtained by second-order least-squares analysis.Simulation of the coupled primary/secondary flow field was conducted,and the complex flow characteristcs.in the flow field of a shroud passage were achieved including the mean velocity and pressure,as well as the eddy in a large scale of flow field due to viscosity.The rotordynamic force coefficients were calculat-ed,and the results were in good agreement with those of experiment except for the direct inertial coefficient without the consideration of whirling forces from the impeller primary flow passage.

  5. Method for mitigating the negative effect of vortex motion inside the suction chambers of centrifugal pumps

    Directory of Open Access Journals (Sweden)

    Adrian CIOCANEA

    2013-09-01

    Full Text Available The paper presents a method for mitigating the negative effect of vortex motion inside the suction chambers of centrifugal pumps in order to obtain better use of water resource and decrease the risk related to loss of prime. It was studied the influence of a rotating device on the vortex motion in the case of a vertical suction pipe. The device is consisting of three thin vertical cylinders symmetrically mounted on a horizontal rotating disk placed in front of the inlet section of the suction pipe. The experimental research was conducted for various diameters of the cylinders, water levels in the suction chamber and pump flow rates. It was assessed the vortex type, frequency of arising and living life of vortices. The experimental results are compared with the case the device is absent in order to assess the efficiency of the solution. By using the device a decrease of about 1215% of vortex arising is observed for most of the water levels in the suction chamber and for 80 -90 % of the centrifugal pump flow rates. If high flow rates and low water level in the suction chamber are simultaneously present, violent vortex motion is blocking the rotating device and the volume of air entered the pipe is massive - extreme regime. The flow pattern in the suction chamber was visualized using a laser sheet. At the inlet section of the suction pipe one can observe two main flow patterns: central vortex entrance for high water level in the suction chamber and reduce flow rates of the centrifugal pump and lateral vortex entrance for low water level and high flow rates. The conclusions of the experiment confirm the energy dissipation of the vortices arising in the suction chamber, due to utilization of the rotating device, in most of the centrifugal pump regimes.

  6. Effect of impeller reflux balance holes on pressure and axial force of centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    CAO Wei-dong; DAI Xun; HU Qi-xiang

    2015-01-01

    The size of impeller reflux holes for centrifugal pump has influence on the pressure distribution of front and rear shrouds and rear pump chamber, as well as energy characteristics of whole pump and axial force. Low specific-speed centrifugal pump with Q=12.5 m3/h,H=60 m,n=2950 r/min was selected to be designed with eight axial reflux balance holes with 4.5 mm in diameter. The simulated Q-H curve and net positive suction head (NPSH) were in good agreement with experimental results, which illustrated that centrifugal pump with axial reflux balance holes was superior in the cavitation characteristic; however, it showed to little superiority in head and efficiency. The pressure in rear pump chamber at 0.6 times rate flow is 29.36% of pressure difference between outlet and inlet, which reduces to 29.10% at rate flow and 28.33% at 1.4 times rate flow. As the whole, the pressure distribution on front and rear shrouds from simulation results is not a standard parabola, and axial force decreases as flow rate increases. Radical reflux balance holes chosen to be 5.2 mm and 5.9 mm in diameter were further designed with other hydraulic parts unchanged. With structural grids adopted for total flow field, contrast numerical simulation on internal flow characteristics was conducted based on momentum equations and standard turbulence model (κ-ε). It is found that axial force of pump with radical reflux balance holes of 5.2 mm and 5.9 mm in diameter is significantly less than that with radical reflux balance holes of 4.5 mm in diameter. Better axial force balance is obtained as the ratio of area of reflux balance holes and area of sealing ring exceeds 6.

  7. Clinical Effectiveness of Centrifugal Pump to Produce Pulsatile Flow During Cardiopulmonary Bypass in Patients Undergoing Cardiac Surgery

    NARCIS (Netherlands)

    Gu, Y. John; van Oeveren, Willem; Mungroop, Hubert E.; Epema, Anne H.; den Hamer, Inez J.; Keizer, Jorrit J.; Leuvenink, Ron P.; Mariani, Massimo A.; Rakhorst, Gerhard

    2011-01-01

    Although the centrifugal pump has been widely used as a nonpulsatile pump for cardiopulmonary bypass (CPB), little is known about its performance as a pulsatile pump for CPB, especially on its efficacy in producing hemodynamic energy and its clinical effectiveness. We performed a study to evaluate w

  8. Centrifugal and Axial Pump Design and Off-Design Performance Prediction

    Science.gov (United States)

    Veres, Joseph P.

    1995-01-01

    A meanline pump-flow modeling method has been developed to provide a fast capability for modeling pumps of cryogenic rocket engines. Based on this method, a meanline pump-flow code PUMPA was written that can predict the performance of pumps at off-design operating conditions, given the loss of the diffusion system at the design point. The design-point rotor efficiency and slip factors are obtained from empirical correlations to rotor-specific speed and geometry. The pump code can model axial, inducer, mixed-flow, and centrifugal pumps and can model multistage pumps in series. The rapid input setup and computer run time for this meanline pump flow code make it an effective analysis and conceptual design tool. The map-generation capabilities of the code provide the information needed for interfacing with a rocket engine system modeling code. The off-design and multistage modeling capabilities of PUMPA permit the user to do parametric design space exploration of candidate pump configurations and to provide head-flow maps for engine system evaluation.

  9. Investigation on impeller radial force for double-suction centrifugal pump with staggered blade arrangement

    International Nuclear Information System (INIS)

    In order to find the effects of blade arrangement on impeller radial force, a double-suction centrifugal pump with two impeller configurations is investigated by using CFD approach. The two impeller have same geometry, same blade number, and different blade arrangement. One is staggered impeller in which the blades are arranged with half of blade phase angle staggered in circular direction, another is traditional symmetrical impeller with symmetrical blade arrangement. Results show that the radial force vector diagram for symmetrical impeller is a hexagonal, while it is nearly a circle for staggered impeller. The staggered impeller results no radial force saltation which exists in symmetrical impeller. The blade passing frequency dominates the radial force fluctuation in symmetrical impeller, while this frequency is almost not existed in staggered impeller. The results indicate that staggered blade arrangement can significantly reduce radial force fluctuation in double-suction centrifugal pump

  10. Investigation on impeller radial force for double-suction centrifugal pump with staggered blade arrangement

    Science.gov (United States)

    Zhang, Z. C.; Wang, F. J.; Yao, Z. F.; Leng, H. F.; Zhou, P. J.

    2013-12-01

    In order to find the effects of blade arrangement on impeller radial force, a double-suction centrifugal pump with two impeller configurations is investigated by using CFD approach. The two impeller have same geometry, same blade number, and different blade arrangement. One is staggered impeller in which the blades are arranged with half of blade phase angle staggered in circular direction, another is traditional symmetrical impeller with symmetrical blade arrangement. Results show that the radial force vector diagram for symmetrical impeller is a hexagonal, while it is nearly a circle for staggered impeller. The staggered impeller results no radial force saltation which exists in symmetrical impeller. The blade passing frequency dominates the radial force fluctuation in symmetrical impeller, while this frequency is almost not existed in staggered impeller. The results indicate that staggered blade arrangement can significantly reduce radial force fluctuation in double-suction centrifugal pump.

  11. SEQUENTIAL DIAGNOSIS FOR A CENTRIFUGAL PUMP BASED ON FUZZY NEURAL NETWORK

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiong; WANG Huaqing; CHEN Peng; TANG Yike

    2008-01-01

    A sequential diagnosis method is proposed based on a fuzzy neural network realized by "the partially-linearized neural network (PNN)", by which the fault types of rotating machinery can be precisely and effectively distinguished at an early stage on the basis of the possibilities of symptom parameters. The non-dimensional symptom parameters in time domain are defined for reflecting the features of time signals measured for the fault diagnosis of rotating machinery. The synthetic detection index is also proposed to evaluate the sensitivity of non-dimensional symptom parameters for detecting faults. The practical example of condition diagnosis for detecting and distinguishing fault states of a centrifugal pump system, such as cavitation, impeller eccentricity which often occur in a centrifugal pump system, are shown to verify the efficiency of the method proposed in this paper.

  12. Numerical and Experimental Investigation of Cavitating Characteristics in Centrifugal Pump with Gap Impeller

    Science.gov (United States)

    Zhu, Bing; Chen, Hongxun; Wei, Qun

    2014-06-01

    This paper is to study the cavitating characteristics in a low specific speed centrifugal pump with gap structure impeller experimentally and numerically. A scalable DES numerical method is proposed and developed by introducing the von Karman scale instead of the local grid scale, which can switch at the RANS and LES region interface smoothly and reasonably. The SDES method can detect and grasp unsteady scale flow structures, which were proved by the flow around a triangular prism and the cavitation flow in a centrifugal pump. Through numerical and experimental research, it's shown that the simulated results match qualitatively with tested cavitation performances and visualization patterns, and we can conclude that the gap structure impeller has a superior feature of cavitation suppression. Its mechanism may be the guiding flow feature of the small vice blade and the pressure auto-balance effect of the gap tunnel.

  13. Fluid-Structure Interaction Analysis on Turbulent Annular Seals of Centrifugal Pumps during Transient Process

    OpenAIRE

    Dazhuan Wu; Leqin Wang; Qinglei Jiang; Lulu Zhai

    2011-01-01

    The current paper studies the influence of annular seal flow on the transient response of centrifugal pump rotors during the start-up period. A single rotor system and three states of annular seal flow were modeled. These models were solved using numerical integration and finite difference methods. A fluid-structure interaction method was developed. In each time step one of the three annular seal models was chosen to simulate the annular seal flow according to the state of rotor systems. The ...

  14. Multicondition Optimization and Experimental Measurements of a Double-Blade Centrifugal Pump Impeller

    OpenAIRE

    Liu, Houlin; Kai WANG; Yuan, Shouqi; Tan, Minggao; Wang, Yong; Dong, Liang

    2012-01-01

    In order to improve internal unsteady flow in a double-blade centrifugal pump (DBCP), this study used major geometric parameters of the original design as the initial values, heads at three conditions (i.e., 80% design flow rate, 100% design flow rate, and 120% design flow rate) as the constraints conditions, and the maximum of weighted average efficiency at the three conditions as the objective function. An adaptive simulated annealing algorithm was selected to solve the energy performance c...

  15. Experimental Measurements of Hydrodynamic Radial Forces and Stiffness Matrices for a Centrifugal Pump-Impeller

    OpenAIRE

    Chamieh, Dmitri S.; Acosta, Allan J.; Brennen, Christopher E.; Caughey, Thomas K.

    1985-01-01

    The present work is an experimental investigation of the possible forces of fluid dynamic origin that can act on a turbomachine rotor particularly when it is situated off its normal center position. An experimental facility, the Rotor Force Test Facility, has been designed and contructed in order to measure these kinds of forces acting on a centrifugal pump impeller when the latter is made to whirl in a slightly eccentric circular orbit. The scope of the present experimental work consists o...

  16. Experimental Investigation of Rotor-Stator Interaction in a Centrifugal Pump with Several Vaned Diffusers

    OpenAIRE

    Arndt, N.; Acosta, A. J.; Brennen, C. E.; Caughey, T. K.

    1990-01-01

    This paper describes an experimental investigation of rotor-stator interaction in a centrifugal pump with several vaned diffusers. Steady and unsteady diffuser vane pressure measurements were made for a two-dimensional test impeller. Unsteady impeller blade pressure measurements were made for a second two-dimensional impeller with blade number and blade geometry identical to the two-dimensional impeller used for the diffuser vane pressure measurements. The experiments were conducted for di...

  17. Modal Analysis of a Centrifugal Pump Impeller Using Finite Element Method

    OpenAIRE

    Ashri Muhammad; Karuppanan Saravanan; Patil Santosh; Ibrahim Idris

    2014-01-01

    The turbo machinery design has evolved rapidly in the last 50 years. The development in the design of any turbo machinery involves interdisciplinary process, namely stress analysis, vibration analysis, fluid dynamics, thermodynamics and the material selection. One of the major and common analyses used in the development of any mechanical part subjected to dynamic loading is the modal analysis. In this paper, the dynamic characteristics of an impeller of a centrifugal pump were studied. The dy...

  18. Maintenance optimisation of centrifugal pumps in a European refinery: : A case study

    OpenAIRE

    Laquet, Andrei

    2015-01-01

    Maintenance has gained credit over the past decades. The oil and gas industry requires efficient maintenance programs due to the hazardousness surrounding the industry. Crude oil margins are also dropping and maintenance yields high controllable costs. Therefore, safety and economy are the driving forces of maintenance optimisation. Refineries have to operate when margins are the most profitable so reliability is crucial.Centrifugal pumps are essential features of the refining process. Due to...

  19. Pressure Fluctuation in a Vaned Diffuser Downstream from a Centrifugal Pump Impeller

    OpenAIRE

    Akinori Furukawa; Hisasada Takahara; Takahiro Nakagawa; Yusuke Ono

    2003-01-01

    Periodic flows downstream from a centrifugal pump impeller in vaneless and vaned diffusers were measured by using a single hole yawmeter and a phase-locked sampling method. The flows were also calculated by an inviscid flow analysis using the blade-surface singularity method. The periodic variations in calculated static pressure with the impeller rotating quantitatively agree well with the measured ones. The flow behaviors in the vaned diffuser are discussed, citing measured and calculated re...

  20. Discussion on the Performance of Multistage Centrifugal Pumps%多级离心泵性能的探讨

    Institute of Scientific and Technical Information of China (English)

    赵义; 于文华; 宋杨; 蔡亚光

    2011-01-01

    Considering the hydraulic loss, volumetric loss and mechanical loss of factors influencing multistage centrifugal pumps and different factors is revealed, pumps. pumps are presented and the relatio which provides theory basis and methods centrifugal pumps, through experiments, the nship between the efficiency of centrifugal for the efficient use of multistage centrifugal%综合考虑了离心水泵的水力损失、容积损失和机械损失,通过实验提出了影响多级离心泵性能的因素,揭示了离心泵使用效率与各因素的关系,为高效使用多级离心水泵提供了理论依据和方法。

  1. Experimental Investigation on Characteristics of Flow Instabilities in Centrifugal Pump Impeller under Part-Load Conditions

    OpenAIRE

    Denghao Wu; Yun Ren; Houlin Liu; Jiegang Mu; Lanfang Jiang

    2014-01-01

    This paper presents an experimental investigation of large-scale flow-field instabilities in a centrifugal pump impeller of low specific speed. Measurements of pump hydraulic performance and flow-field in the impeller passages were made with a hydraulic test rig and a Particle Image Velocimetry (PIV) system separately. Analyses of Q-H data and flow structures in the impeller passages were performed. Results showed that an unstable area existed in the range from 0.1QBEP to 0.6QBEP and had a cl...

  2. Numerical Flow Simulation in a Centrifugal Pump at Design and Off-Design Conditions

    OpenAIRE

    Cheah, K. W.; Lee, T. S.; S. H. Winoto; Z. M. Zhao

    2007-01-01

    The current investigation is aimed to simulate the complex internal flow in a centrifugal pump impeller with six twisted blades by using a three-dimensional Navier-Stokes code with a standard k-ε two-equation turbulence model. Different flow rates were specified at inlet boundary to predict the characteristics of the pump. A detailed analysis of the results at design load, Qdesign, and off-design conditions, Q = 0.43 Qdesign and Q = 1.45 Qdesign, is presented. From t...

  3. Numerical Modelization of the Flow in Centrifugal Pump: Volute Influence in Velocity and Pressure Fields

    OpenAIRE

    Miguel Asuaje; Farid Bakir; Smaïne Kouidri; Frank Kenyery; Robert Rey

    2005-01-01

    A 3D-CFD simulation of the impeller and volute of a centrifugal pump has been performed using CFX codes. The pump has a specific speed of 32 (metric units) and an outside impeller diameter of 400 mm. First, a 3D flow simulation for the impeller with a structured grid is presented. A sensitivity analysis regarding grid quality and turbulence models were also performed. The final impeller model obtained was used for a 3D quasi-unsteady flow simulation of the impeller-volute...

  4. Experimental investigation of rotor-stator interaction in a centrifugal pump with several vaned diffusers

    Science.gov (United States)

    Arndt, N.; Acosta, A. J.; Brennen, C. E.; Caughey, T. K.

    1990-01-01

    Steady and unsteady diffuser vane pressure measurements have been conducted with a two-dimensional test impeller, in an experimental investigation of rotor-stator interaction within a centrifugal pump having several vaned diffusers, under conditions of different flow coefficients and different radial gaps between the impeller blade trailing edge and the diffuser vane leading edge. The largest pressure fluctuations on the diffuser vanes and the impeller blades were found to be of the same order of magnitude as the total pressure rise across the pump. Increasing the number of diffuser vanes was found to result in a significant decrease of impeller blade pressure fluctuations.

  5. Experimental and Numerical Investigation of Radial Forces Acting on Centrifugal Pump Impeller

    Directory of Open Access Journals (Sweden)

    Karaskiewicz Krzysztof

    2014-12-01

    Full Text Available The paper presents the results of measurements and predictions of radial thrust in centrifugal pump with specific speed ns = 26. In the pump tested, a volute with rectangular cross-section was used. The tests were carried out for several rotational speeds, including speeds above and below the nominal one. Commercial code ANSYS Fluent was used for the calculations. Apart from the predictions of the radial force, the calculations of axial thrust were also conducted, and correlation between thrust and the radial force was found. In the range of the measured rotational speeds, similarity of radial forces was checked.

  6. A 2.5D Single Passage CFD Model for Centrifugal Pumps

    Science.gov (United States)

    Nakamura S.; Ding, W.; Yano, K.

    1998-01-01

    This paper describes the single passage model based on CFD to analyze the flow in blade passages of a centrifugal pump. The model consists of the flow passage between two impeller blades and the spaces in the inlet eye as well as in the volute. The incompressible Navier-Stokes equations in the conservation form are solved by a finite difference method. The code is designed to investigate the velocity and pressure distributions and intended to investigate how the pump design affects fluid flow through the rotor as well as the pump performance. An early part of the paper investigates the behavior of the model as well as validity of the assumptions made in the model. Then, applications to a rotodynamic heart pump are presented.

  7. Investigation of Flow Through Centrifugal Pump Impellers Using Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Weidong Zhou

    2003-01-01

    Full Text Available With the aid of computational fluid dynamics, the complex internal flows in water pump impellers can be well predicted, thus facilitating the design of pumps. This article describes the three-dimensional simulation of internal flow in three different types of centrifugal pumps (one pump has four straight blades and the other two have six twisted blades. A commercial three-dimensional Navier-Stokes code called CFX, with a standard k–ε two-equation turbulence model was used to simulate the problem under examination. In the calculation, the finite-volume method and an unstructured grid system were used for the solution procedure of the discretized governing equations for this problem.

  8. Cavitation characteristics of a small centrifugal pump in He I and He II

    Science.gov (United States)

    Ludtke, P. R.; Daney, D. E.

    1988-01-01

    The cavitation characteristics of a small preinduced centrifugal pump operating in He I and He II over the temperature range 1.8-4.2 K are presented. The pump and close-coupled induction motor operate immersed in liquid helium. A six-blade propeller inducer and a three-blade screw inducer were both tested. With this pump configuration using either inducer, there is a tremendous difference between the cavitation characteristics of He I and He II. The net positive suction head requirements for this pump with the screw inducer could not be determined for He I, but it is less than -100 mm and, depending on flow rate, ranges between 35 and 165 mm for He II.

  9. Influence of blade outlet angle on performance of low-specific-speed centrifugal pump

    Science.gov (United States)

    Cui, Baoling; Wang, Canfei; Zhu, Zuchao; Jin, Yingzi

    2013-04-01

    In order to analyze the influence of blade outlet angle on inner flow field and performance of low-specific-speed centrifugal pump, the flow field in the pump with different blade outlet angles 32.5° and 39° was numerically calculated. The external performance experiment was also carried out on the pump. Based on SIMPLEC algorithm, time-average N-S equation and the rectified k-ɛ turbulent model were adopted during the process of computation. The distributions of velocity and pressure in pumps with different blade outlet angles were obtained by calculation. The numerical results show that backflow areas exist in the two impellers, while the inner flow has a little improvement in the impeller with larger blade outlet angle. Blade outlet angle has a certain influence on the static pressure near the long-blade leading edge and tongue, but it has little influence on the distribution of static pressure in the passages of impeller. The experiment results show that the low-specific-speed centrifugal pump with larger blade outlet angle has better hydraulic performance.

  10. Numerical analysis for causes of cavitation fracture working condition on centrifugal pump

    International Nuclear Information System (INIS)

    In order to research the flow-head curve plunge caused by the cavitation of centrifugal pump, the standard k-ε turbulence model, homogeneous multiphase model and Rayleigh-Plesset equation were applied to simulate the cavitation characteristics in a centrifugal pump with specific speed of 59 under different conditions based on ANSYS CFX software. The results show that the numerical simulation result has the same trend with experiment result, and absolute error is 0.02%. The analysis of flow field shows that: the steep fall of flow-head curve is not only caused by the traditional cavitation, but also mainly caused by the Vortex loss. As the empty bubble in the passageway increases to some degree, the liquid boundary layer separation happened, then vortex appears and vortex losses. While the vortex appears originally, it has an impact on the flow-head curve. When the bubble becomes more and the whole passageway is full of vortex, cavitation fault condition happens. It reveals the vapor-liquid tow-phase flow distribution within the centrifugal pump. (authors)

  11. Flow analysis of centrifugal pump using CFX solver and remedies for cavitation mitigation

    Directory of Open Access Journals (Sweden)

    Dr. G. Rambabu,

    2015-07-01

    Full Text Available In this scholarly thesis pertinent to the working of centrifugal pump, a CFD solver namely CFX is employed in order to simulate fluid flow characteristics with well-defined constraints and boundary conditions defining the problem. Stringent solid model is meticulously prepared encompassing the present day usage and constructional features of a centrifugal pump and is constrained with various boundary conditions having fixed domain in order to evaluate plots and results. To spearhead and facilitate this analysis program a numerical approximation tool with high degree of convergence rate called ANSYS 15.0 software is used. The ASNYS software avoids tedious calculations presumably impending in the design procedure and uses ultimate numerical tool to approximate the solution of the partial differential equations associated with continuity, momentum and energy phases of a flow problem in a 3-D model. This exquisite feature of ANSYS enables designer to optimize the design procedure in an iterative manner based on the final plots of post-processing phase. In addition, the scholarly writing also constitutes the appraisal of the most debilitating and painstaking problem retarding the efficiency of the centrifugal pump known as cavitation. Possible remedies for overcoming this problem will be indirectly inferred from the various plots and figures derived from the post-processing phase of the design process.

  12. Numerical Investigation of Pressure Fluctuation Characteristics in a Centrifugal Pump with Variable Axial Clearance

    Directory of Open Access Journals (Sweden)

    Lei Cao

    2016-01-01

    Full Text Available Clearance flows in the sidewall gaps of centrifugal pumps are unsteady as well as main flows in the volute casing and impeller, which may cause vibration and noise, and the corresponding pressure fluctuations are related to the axial clearance size. In this paper, unsteady numerical simulations were conducted to predict the unsteady flows within the entire flow passage of a centrifugal pump operating in the design condition. Pressure fluctuation characteristics in the volute casing, impeller, and sidewall gaps were investigated with three axial clearance sizes. Results show that an axial clearance variation affects the pressure fluctuation characteristics in each flow domain by different degree. The greatest pressure fluctuation occurs at the blade pressure surface and is almost not influenced by the axial clearance variation which has a certainly effect on the pressure fluctuation characteristics around the tongue. The maximum pressure fluctuation amplitude in the sidewall gaps is larger than that in the volute casing, and different spectrum characteristics show up in the three models due to the interaction between the clearance flow and the main flow as well as the rotor-stator interaction. Therefore, clearance flow should be taken into consideration in the hydraulic design of centrifugal pumps.

  13. MOTION OF TRACER PARTICLES IN A CENTRIFUGAL PUMP AND ITS TRACKING CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    LI Ya-lin; YUAN Shou-qi; TANG Yue; YUAN Jian-ping

    2012-01-01

    The Basset-Boussinesq-Oseen (BBO) equation can be used for most flows to trace the motion of a particle,but in a centrifugal pump,among the forces that act on the particles,one should also include those due to the impeller rotation,as additional effects.This paper firstly reviews various approximations of the BBO equation for the motion of dispersion particles in a viscous fluid.Then based on the motion equation for particles in low Reynolds number centrifugal pumps,a formula for calculating the tracking characteristics of tracer particles is deduced through the Fourier integral transformation.After that the deviations of the particle motion from the fluid motion,as predicted by the various approximations,are discussed and compared.At last,with an emphasis on the Particle Image Velocimetry (PIV) results,the tracking characteristics of particles are estimated.Also,advantages and disadvantages of different tracer particles are discussed and suitable tracer particles for application in PIV studies for flow fields in centrifugal pumps are suggested.

  14. CAVITATING SUPPRESSION OF LOW SPECIFIC SPEED CENTRIFUGAL PUMP WITH GAP DRAINAGE BLADES

    Institute of Scientific and Technical Information of China (English)

    ZHU Bing; CHEN Hong-xun

    2012-01-01

    This paper aims to clarify the cavitation suppression mechanism of the gap structure impeller based on the analysis of cavitation characteristics in a low specific speed centrifugal pump.In order to obtain reliable and consistent numerical results,some numerical considerations and modeling methodology were demonstrated and researched,and a check of the time and space resolution were also conducted.Hence the predicted cavitation performance of the two centrifugal pumps were investigated and compared with experimental results,and they were in qualitative agreement.It was confirmed that the new gap structure impeller has a very good characteristic of inhibiting cavitation,especially in large flow area,the present numerical method can effectively capture the major internal flow features in the centrifugal pump,through the comparison of the two type impeller flow fields,the cavitation suppression mechanism of the gap impeller may be the combination effects of the small vice blade's guiding flow and gap tunnel's auto-balancing of pressure.

  15. Component Analysis of Unsteady Hydrodynamic Force of Closed-Type Centrifugal Pump with Single Blades of Different Blade Outlet Angles

    OpenAIRE

    Yasuyuki Nishi; Junichiro Fukutomi

    2015-01-01

    Single-blade centrifugal impellers for sewage systems undergo both unsteady radial and axial thrusts. Therefore, it is extremely important for the improvement of pump reliability to quantitatively grasp these fluctuating hydrodynamic forces and determine the generation mechanism behind them. In this study, we conducted component analyses of radial and axial thrusts of closed, single-blade centrifugal pumps with different blade outlet angles by numerical analysis while considering leakage flow...

  16. A Comparative Assessment of Spalart-Shur Rotation/Curvature Correction in RANS Simulations in a Centrifugal Pump Impeller

    OpenAIRE

    Ran Tao; Ruofu Xiao; Wei Yang; Fujun Wang

    2014-01-01

    RANS simulation is widely used in the flow prediction of centrifugal pumps. Influenced by impeller rotation and streamline curvature, the eddy viscosity models with turbulence isotropy assumption are not accurate enough. In this study, Spalart-Shur rotation/curvature correction was applied on the SST k-ω turbulence model. The comparative assessment of the correction was proceeded in the simulations of a centrifugal pump impeller. CFD results were compared with existing PIV and LDV data under ...

  17. Experimental investigation and numerical analysis of unsteady attached sheet-cavitating flows in a centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    LIU Hou-lin; LIU Dong-xi; WANG Yong; WU Xian-fang; WANG Jian; DU Hui

    2013-01-01

    This paper studies the attached sheet cavitation in centrifugal pumps.A pump casted from Perspex is used as the test subject.The cavitation bubbles were observed in the entrance of the impeller and the drops of the head coefficients were measured under different operating conditions.A Filter-Based Model (FBM),derived from the RNG k-ε model,and a modified Zwart model are adopted in the numerical predictions of the unsteady cavitating flows in the pump.The simulations are carried out and the results are compared with experimental results for 3 different flow coefficients,from 0.077 to 0.114.Under four operating conditions,qualitative comparisons are made between experimental and numerical cavitation patterns,as visualized by a high-speed camera and described as isosurfaces of the vapour volume fraction αv =0.1.It is shown that the simulation can truly represent the development of the attached sheet cavitation in the impeller.At the same time,the curves for the drops of the head coefficients obtained from experiments and calculations are also quantitatively compared,which shows that the decline of the head coefficients at every flow coefficient is correctly captured,and the prediction accuracy is high.In addition,the detailed analysis is made on the vapour volume fraction contours on the plane of span is 0.5 and the loading distributions around the blade section at the midspan.It is shown that the FBM model and the modified Zwart model are effective for the numerical simulation of the cavitating flow in centrifugal pumps.The analysis results can also be used as the basis for the further research of the attached sheet cavitation and the improvement of centrifugal pumps.

  18. Dynamic stress analysis of sewage centrifugal pump impeller based on two-way coupling method

    Science.gov (United States)

    Pei, Ji; Yuan, Shouqi; Yuan, Jianping

    2014-03-01

    Current research on the operational reliability of centrifugal pumps has mainly focused on hydrodynamic instability. However, the interaction between the fluid and structure has not been sufficiently considered; this interaction can cause vibration and dynamic stress, which can affect the reliability. In this study, the dynamic stresses in a single-blade centrifugal pump impeller are analysed under different operating conditions; the two-way coupling method is used to calculate the fluid-structure interaction. Three-dimensional unsteady Reynolds-averaged Navier-Stokes equations are solved with the SST k-ω turbulence model for the fluid in the whole flow passage, while transient structure dynamic analysis is used with the finite element method for the structure side. The dynamic stresses in the rotor system are computed according to the fourth strength theory. The stress results show that the highest stress is near the loose bearing and that the equivalent stress increases with the flow rate because the dynamic stresses are closely related to the pressure load. The stress distributions on the blade pressure side, suction side, leading edge, and trailing edge are each analysed for different flow rates; the highest stress distribution is found on the pressure side. On the blade pressure side, a relatively large stress is found near the trailing edge and hub side. Based on these results, a stress distribution prediction method is proposed for centrifugal pumps, which considers the interaction between the fluid and structure. The method can be used to check the dynamic stress at different flow rates when optimising the pump design to increase the pump reliability.

  19. Numerical simulation on dimension decrease for annular casing of one centrifugal boiler circulation pump

    International Nuclear Information System (INIS)

    Primary formulation derivation indicates that the dimension of one existing centrifugal boiler circulation pump casing is too large. As great manufacture cost can be saved by dimension decrease, a numerical simulation research is developed in this paper on dimension decrease for annular casing of this pump with a specific speed equaling to 189, which aims at finding an appropriately smaller dimension of the casing while hydraulic performance and strength performance will hardly be changed according to the requirements of the cooperative company. The research object is one existing centrifugal pump with a diffuser and a semi-spherical annular casing, working as the boiler circulation pump for (ultra) supercritical units in power plants. Dimension decrease, the modification method, is achieved by decreasing the existing casing's internal radius (marked as Ri0) while keeping the wall thickness. The research analysis is based on primary formulation derivation, CFD (Computational Fluid Dynamics) simulation and FEM (Finite Element Method) simulation. Primary formulation derivation estimates that a design casing's internal radius should be less than 0.75 Ri0. CFD analysis indicates that smaller casing with 0.75 Ri0 has a worse hydraulic performance when working at large flow rates and a better hydraulic performance when working at small flow rates. In consideration of hydraulic performance and dimension decrease, an appropriate casing's internal radius is determined, which equals to 0.875 Ri0. FEM analysis then confirms that modified pump casing has nearly the same strength performance as the existing pump casing. It is concluded that dimension decrease can be an economical method as well as a practical method for large pumps in engineering fields.

  20. Quality evaluation of energy consumed in flow regulation method by speed variation in centrifugal pumps

    Science.gov (United States)

    Morales, S.; Culman, M.; Acevedo, C.; Rey, C.

    2014-06-01

    Nowadays, energy efficiency and the Electric Power Quality are two inseparable issues in the evaluation of three-phase induction motors, framed within the program of Rational and Efficient Use of Energy (RUE).The use of efficient energy saving devices has been increasing significantly in RUE programs, for example the use of variable frequency drives (VFD) in pumping systems.The overall objective of the project was to evaluate the impact on power quality and energy efficiency in a centrifugal pump driven by an induction three-phase motor, using the flow control method of speed variation by VFD. The fundamental purpose was to test the opinions continuously heard about the use of flow control methods in centrifugal pumps, analyzing the advantages and disadvantages that have been formulated deliberately in order to offer support to the industry in taking correct decisions. The VFD changes the speed of the motor-pump system increasing efficiency compared to the classical methods of regulation. However, the VFD originates conditions that degrade the quality of the electric power supplied to the system and therefore its efficiency, due to the nonlinearity and presence of harmonic currents. It was possible to analyze the power quality, ensuring that the information that comes to the industry is generally biased.

  1. 浅析石化企业离心泵的汽蚀及提高其抗汽蚀性能的措施%Petrochemical Enterprise Centrifugal Pump Cavitation and Improve the Centrifugal Pump Cavitation Performance of Measures

    Institute of Scientific and Technical Information of China (English)

    龚智喜; 刘鹏飞; 张博; 许东莉

    2012-01-01

    离心泵是石油化工企业运用最广泛的输能流体机械。在使用过程中怎样防止离心泵的汽蚀,怎样去减少汽蚀对离心泵的损害是非常重要的。汽蚀是一种十分有害的现象,它使离心泵的扬程,流量和效率明显下降,严重时泵甚至不能够运转,所以研究泵的汽蚀并采取相应的措施有助于提高泵的使用效率和延长泵的寿命等。%Centrifugal pump is the most widely used oil chemical enterprise of can lose fluid machinery.In use process how to prevent the centrifugal pump cavitation,how to reduce the cavitation in a centrifugal pump damage is very important.Cavitation is a kind of very harmful phenomenon,it makes the centrifugal pump hit,flow rate and efficiency decreases significantly,serious when pump can't even run,so the study of pump cavitation and take some measures to improve the efficiency in the use of pump and to extend the pump life.

  2. Improved Outcome of Cardiac Extracorporeal Membrane Oxygenation in Infants and Children Using Magnetic Levitation Centrifugal Pumps.

    Science.gov (United States)

    Luciani, Giovanni Battista; Hoxha, Stiljan; Torre, Salvatore; Rungatscher, Alessio; Menon, Tiziano; Barozzi, Luca; Faggian, Giuseppe

    2016-01-01

    Extracorporeal membrane oxygenation (ECMO) has traditionally been and, for the most part, still is being performed using roller pumps. Use of first-generation centrifugal pumps has yielded controversial outcomes, perhaps due to mechanical properties of the same and the ensuing risk of hemolysis and renal morbidity. Latest-generation centrifugal pumps, using magnetic levitation (ML), exhibit mechanical properties which may have overcome limitations of first-generation devices. This retrospective study aimed to assess the safety and efficacy of veno-arterial (V-A) ECMO for cardiac indications in neonates, infants, and children, using standard (SP) and latest-generation ML centrifugal pumps. Between 2002 and 2014, 33 consecutive neonates, infants, and young children were supported using V-A ECMO for cardiac indications. There were 21 males and 12 females, with median age of 29 days (4 days-5 years) and a median body weight of 3.2 kg (1.9-18 kg). Indication for V-A ECMO were acute circulatory collapse in ICU or ward after cardiac repair in 16 (49%) patients, failure to wean after repair of complex congenital heart disease in 9 (27%), fulminant myocarditis in 4 (12%), preoperative sepsis in 2 (6%), and refractory tachy-arrhythmias in 2 (6%). Central cannulation was used in 27 (81%) patients and peripheral in 6. Seven (21%) patients were supported with SP and 26 (79%) with ML centrifugal pumps. Median duration of support was 82 h (range 24-672 h), with 26 (79%) patients weaned from support. Three patients required a second ECMO run but died on support. Seventeen (51%) patients required peritoneal dialysis for acute renal failure. Overall survival to discharge was 39% (13/33 patients). All patients with fulminant myocarditis and with refractory arrhythmias were weaned, and five (83%) survived, whereas no patient supported for sepsis survived. Risk factors for hospital mortality included lower (<2.5 kg) body weight (P = 0.02) and rescue ECMO after cardiac

  3. New inverse method of centrifugal pump blade based on free form deformation

    International Nuclear Information System (INIS)

    In this research, a new inverse method for centrifugal pump blade based on free form deformation is proposed, the free form deformation is used to parametric the pump blade. The blade is implanted to a trivariate control volume which is equally subdivided by control lattice. The control volume can be deformed by moving the control lattice, thereupon the object is deformed. The flow in pump is solved by using a three dimensional turbulent model. The lattice deformation function is constructed according to the gradient distribution of fluid energy along the blade and its objective distribution. Deform the blade shape continually according to the flow solve, and we can get the objective blade shape. The calculation case shows that the proposed inverse method based on FFD method is rational

  4. Impellers of low specific speed centrifugal pump based on the draughting technology

    International Nuclear Information System (INIS)

    The authors analyzed the reasons of low efficiency under different operation condition based on the performance test and CFD numerical simulation approach. And the analysis focuses on the relationship between pump efficiency and inner flow characteristics. In order to improve the internal flow and increase efficiency of the pump, some draughting methods of improving the internal flow structure have been proposed, and some new impellers were developed by these methods. The main geometric parameters of the impellers, such as diameter, width and installation of the size, were consistent with the original impeller. The experimental results show that the efficiency of new impellers was improved significantly. The authors' work has opened up a new direction for further improving the efficiency of the low specific speed centrifugal pump.

  5. Experimental measurements of hydrodynamic radial forces and stiffness matrices for a centrifugal pump-impeller

    Science.gov (United States)

    Chamieh, D. S.; Acosta, A. J.; Brennen, C. E.; Caughey, T. K.

    1985-01-01

    Measurements of the steady-state hydrodynamic forces on a centrifugal pump impeller are presented as a function of position within two geometrically different volutes. These correspond to the forces experienced by the impeller at zero whirl frequency. The hydrodynamic force matrices derived from these measurements exhibit both diagonal and off-diagonal terms of substantial magnitude. These terms are of the form which would tend to excite a whirl motion in a rotordynamic analysis of the pump; this may be the cause of 'rough running' reported in many pumps. Static pressure measurements in the impeller discharge flow show that the hydrodynamic force on the impeller contains a substantial component due to the nonisotropy of the net momentum flux leaving the impeller. A similar breakdown of the contributions to the stiffness matrices reveals that the major component of these matrices results from the nonisotropy of the momentum flux.

  6. Numerical investigation of unsteady turbulent flow in a centrifugal pump at partial load

    International Nuclear Information System (INIS)

    The unsteady non-cavitation and cavitation turbulent flows in a centrifugal pump at partial load condition are numerically investigated by CFX 13.0. The numerical framework employs the combination of RNG k-ε turbulence model and transport equation cavitation model, in which the effects of compressibility of fluid on cavitation region and pressure fluctuation on saturation pressure are both taken into consideration. The good agreement between the numerical and experimental values validates that the numerical framework can accurately predict the turbulent flows in the centrifugal pump. The complex flow characteristics in impeller at non-cavitation and cavitation conditions are revealed. For the noncavitation flow, the dominant frequencies of pressure fluctuation of monitoring points in impeller are all the Impeller Rotation Frequency 24.17Hz. The maximum value of pressure fluctuation on the blade pressure side appears at the 0.8 chord length from the blade leading edge due to a clockwise rotating vortex, which incepts, develops and disappears when the corresponding blade passes through the volute tongue. The dominant frequencies of pressure fluctuation of monitoring points in volute are the Blade Pass Frequency 145 Hz or twice of it. The maximum value of pressure fluctuation in the volute appears near the tongue region, where the flow fields are uneven with strong second flow in the cross section. For the cavitation flow, as the cavitation develops at the blade leading edge, the turbulent flows in the impeller are greatly influenced by the bubble shedding and collapse. The maximum values of pressure fluctuation in impeller increase with the development of cavitation, and reach the largest magnification of about 2.0 in comparison to the non-cavitation flow when the pressure at the pump inlet is very low. The complicated phenomenon of unsteady turbulent flow in a centrifugal pump indicates that the vortex has great influence on the flow pattern

  7. Numerical investigation of unsteady turbulent flow in a centrifugal pump at partial load

    Science.gov (United States)

    Lei, T.; Baoshan, Z.; ShuLiang, C.; Yuchuan, W.; Xuhe, W.

    2014-03-01

    The unsteady non-cavitation and cavitation turbulent flows in a centrifugal pump at partial load condition are numerically investigated by CFX 13.0. The numerical framework employs the combination of RNG k-ε turbulence model and transport equation cavitation model, in which the effects of compressibility of fluid on cavitation region and pressure fluctuation on saturation pressure are both taken into consideration. The good agreement between the numerical and experimental values validates that the numerical framework can accurately predict the turbulent flows in the centrifugal pump. The complex flow characteristics in impeller at non-cavitation and cavitation conditions are revealed. For the noncavitation flow, the dominant frequencies of pressure fluctuation of monitoring points in impeller are all the Impeller Rotation Frequency 24.17Hz. The maximum value of pressure fluctuation on the blade pressure side appears at the 0.8 chord length from the blade leading edge due to a clockwise rotating vortex, which incepts, develops and disappears when the corresponding blade passes through the volute tongue. The dominant frequencies of pressure fluctuation of monitoring points in volute are the Blade Pass Frequency 145 Hz or twice of it. The maximum value of pressure fluctuation in the volute appears near the tongue region, where the flow fields are uneven with strong second flow in the cross section. For the cavitation flow, as the cavitation develops at the blade leading edge, the turbulent flows in the impeller are greatly influenced by the bubble shedding and collapse. The maximum values of pressure fluctuation in impeller increase with the development of cavitation, and reach the largest magnification of about 2.0 in comparison to the non-cavitation flow when the pressure at the pump inlet is very low. The complicated phenomenon of unsteady turbulent flow in a centrifugal pump indicates that the vortex has great influence on the flow pattern.

  8. Centrifugal slurry pump wear and hydraulic studies. Phase II report. Experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Mistry, D.; Cooper, P.; Biswas, C.; Sloteman, D.; Onuschak, A.

    1983-01-01

    This report describes the work performed by Ingersoll-Rand Research, Inc., under Phase II, Experimental Studies for the contract entitled, Centrifugal Slurry Pump Wear and Hydraulic Studies. This work was carried out for the US Department of Energy under Contract No. DE-AC-82PC50035. The basic development approach pursued this phase is presented, followed by a discussion on wear relationships. The analysis, which resulted in the development of a mathematical wear model relating pump life to some of the key design and operating parameters, is presented. The results, observations, and conclusions of the experimental investigation on small scale pumps that led to the selected design features for the prototype pump are discussed. The material investigation was performed at IRRI, ORNL and Battelle. The rationale for selecting the materials for testing, the test methods and apparatus used, and the results obtained are presented followed by a discussion on materials for a prototype pump. In addition, the prototype pump test facility description, as well as the related design and equipment details, are presented. 20 references, 53 figures, 13 tables.

  9. Computational fluid dynamics analysis of blade tip clearances on hemodynamic performance and blood damage in a centrifugal ventricular assist device.

    Science.gov (United States)

    Wu, Jingchun; Paden, Bradley E; Borovetz, Harvey S; Antaki, James F

    2010-05-01

    An important challenge facing the design of turbodynamic ventricular assist devices (VADs) intended for long-term support is the optimization of the flow path geometry to maximize hydraulic performance while minimizing shear-stress-induced hemolysis and thrombosis. For unshrouded centrifugal, mixed-flow and axial-flow blood pumps, the complex flow patterns within the blade tip clearance between the lengthwise upper surface of the rotating impeller blades and the stationary pump housing have a dramatic effect on both the hydrodynamic performance and the blood damage production. Detailed computational fluid dynamics (CFD) analyses were performed in this study to investigate such flow behavior in blade tip clearance region for a centrifugal blood pump representing a scaled-up version of a prototype pediatric VAD. Nominal flow conditions were analyzed at a flow rate of 2.5 L/min and rotor speed of 3000 rpm with three blade tip clearances of 50, 100, and 200 microm. CFD simulations predicted a decrease in the averaged tip leakage flow rate and an increase in pump head and axial thrust with decreasing blade tip clearances from 200 to 50 microm. The predicted hemolysis, however, exhibited a unimodal relationship, having a minimum at 100 microm compared to 50 microm and 200 microm. Experimental data corroborate these predictions. Detailed flow patterns observed in this study revealed interesting fluid dynamic features associated with the blade tip clearances, such as the generation and dissipation of tip leakage vortex and its interaction with the primary flow in the blade-blade passages. Quantitative calculations suggested the existence of an optimal blade tip clearance by which hydraulic efficiency can be maximized and hemolysis minimized. PMID:19832736

  10. Numerical Research about Influence of Blade Outlet Angle on Flow-Induced Noise and Vibration for Centrifugal Pump

    OpenAIRE

    Ailing Yang; Dapeng Lang; Guoping Li; Eryun Chen; Ren Dai

    2014-01-01

    A hybrid numerical method was used to calculate the flow-induced noise and vibration of the centrifugal pump in the paper. The unsteady flows inside the centrifugal pumps with different blade outlet angles were simulated firstly. The unsteady pressure on the inner surface of the volute and the unsteady force applied on the impeller were analyzed. Then the vibration of the volute and sound field were calculated based on an acoustic-vibro-coupling method. The results show that the pump head has...

  11. Transient stress-based and strain-based hemolysis estimation in a simplified blood pump.

    Science.gov (United States)

    Pauli, Lutz; Nam, Jaewook; Pasquali, Matteo; Behr, Marek

    2013-10-01

    We compare two approaches to numerical estimation of mechanical hemolysis in a simplified blood pump model. The stress-based model relies on the instantaneous shear stress in the blood flow, whereas the strain-based model uses an additional tensor equation to relate distortion of red blood cells to a shear stress measure. We use the newly proposed least-squares finite element method (LSFEM) to prevent negative concentration fields and show a stable and volume preserving LSFEM for the tensor equation. Application of both models to a simplified centrifugal blood pump at three different operating conditions shows that the stress-based model overestimates the rate of hemolysis. The strain-based model is found to deliver lower hemolysis rates because it incorporates a more detailed description of biophysical phenomena into the simulation process. PMID:23922311

  12. FINITE ELEMENT ANALYSIS OF CENTRIFUGAL PUMP CASINGS TO DETECT THE CRACK AT THE TONGUE REGION.

    Directory of Open Access Journals (Sweden)

    Ramana Podugu

    2011-09-01

    Full Text Available The objective of this paper is to identify one of the reasons for the crack to initiate at the tongue region. The design of the tongue region of the centrifugal pump casing plays an important role in influencing the pump performance and cavitation. Tongue region should have enough strength to withstand against repeated loads imparted by the impeller. Crack at the tongue region is examined under hydrostatic pressure conditions .Practically, at the site location it was observed that the crack was formed at the tongue region when the casing was tested under hydrostatic pressure. Static linear analysis is performed to identify the critical zone where the maximum stress occurs that causes failure. Maximum stress is observed at the tongue region. To reduce the maximum stress, ribs thickness was increased in addition to increasing the portion of the volute thickness. Geometrical modifications are suggested in such a way that there is no effect on the hydraulic performance and to avoid increase in manufacturing cost. Stress distribution of the centrifugal pump casing volute is simulated using finite element software like Ansys. In this paper an attempt was made to validate finite element analysisresults with test conditions and found good concurrence between FEA results and theoretical results.

  13. Numerical Flow Simulation in a Centrifugal Pump at Design and Off-Design Conditions

    Directory of Open Access Journals (Sweden)

    K. W. Cheah

    2007-01-01

    Full Text Available The current investigation is aimed to simulate the complex internal flow in a centrifugal pump impeller with six twisted blades by using a three-dimensional Navier-Stokes code with a standard k-ε two-equation turbulence model. Different flow rates were specified at inlet boundary to predict the characteristics of the pump. A detailed analysis of the results at design load, Qdesign, and off-design conditions, Q = 0.43 Qdesign and Q = 1.45 Qdesign, is presented. From the numerical simulation, it shows that the impeller passage flow at design point is quite smooth and follows the curvature of the blade. However, flow separation is observed at the leading edge due to nontangential inflow condition. The flow pattern changed significantly inside the volute as well, with double vortical flow structures formed at cutwater and slowly evolved into a single vortical structure at the volute diffuser. For the pressure distribution, the pressure increases gradually along streamwise direction in the impeller passages. When the centrifugal pump is operating under off-design flow rate condition, unsteady flow developed in the impeller passage and the volute casing.

  14. TWO-DIMENSIONAL PARTICLE IMAGE VELOCIMETRY(PIV) MEASUREMENTS IN A TRANSPARENT CENTRIFUGAL PUMP

    Institute of Scientific and Technical Information of China (English)

    Yang Hua; Gu Chuangang; Wang Tong

    2005-01-01

    A special transparent centrifugal pump is designed. Detailed optical measurements of the flow inside the rotating passages of a five-bladed shroud centrifugal pump impeller have been performed by using two-dimensional particle image velocimetry (PIV). The flow is surveyed at three load conditions qv/qνd = 0.4, qν/qνd = 1.0, qν/qνd = 1.5, respectively. As a result, phase averaged PIV velocity vector maps on three planes between hub and shroud of the impeller are presented. At design load, the mean field of relative velocity is predominantly vane congruent, showing well-behaved flow without separation. The distributions of the relative velocity on different plane along the pump shaft are very different and there is always a low velocity zone near the pressure-side of the blade at both low and design flow rate, but the low-velocity-zone at the low flow rate is much larger than that at the design one. The study demonstrates that the PIV technique is efficient in providing reliable and detailed velocity data over a full impeller passage.

  15. Numerical Simulation of 3D Solid-Liquid Turbulent Flow in a Low Specific Speed Centrifugal Pump: Performance Comparison of Four Geometric Models

    OpenAIRE

    Baocheng Shi; Jinjia Wei

    2014-01-01

    For numerically simulating 3D solid-liquid turbulent flow in low specific speed centrifugal pumps, there exist several problems including how to design geometrical shape of the calculation model to represent the real pump and how to predict pump performance accurately to guide the design of pump. To solve these problems, four kinds of geometric models were designed. The performance of a low specific speed solid-liquid centrifugal pump was predicted, and the results showed that the improved pr...

  16. Research on the characteristics of quasi-steady cavitation in a centrifugal pump

    Science.gov (United States)

    Lu, J. X.; Yuan, S. Q.; Li, X. J.; Si, Q. R.; Luo, Y.

    2015-01-01

    With the pressure decreasing, the process of cavitation in a centrifugal pump could be summarized as incipient cavitation, quasi-steady cavitation and unsteady cavitation. Quasi-steady cavitation is the condition that is between the incipient cavitation and unsteady cavitation in a centrifugal pump. Under this condition, the intensity of cavitation is relatively weak, and the head of the pump almost remains unchanged, but the cavitation exists, causing damage to the impeller by pitting and erosion. So it is important to investigate the quasi-steady cavitation. In this paper, both the numerical and experimental methods had been carried out to investigate the characteristics of quasi-steady cavitation. The internal flow in the pump, the performance of cavitation and the inlet and outlet pressure pulsation of the pump measured through experimental method have been studied under different NPSHa conditions. It was found that the head decreases about 0.77%-1.38% from non-cavitation condition and it could be regarded as the quasi-steady cavitation. Little change has been found from the internal flow between non-cavitation condition and quasi-steady cavitation condition. The period of inlet pressure pulsation changes from the time that the blade passes by to the period of shaft rotating with the development of cavitation. The dominant frequency of the inlet pressure pulsation is two times of shaft frequency whose amplitudes decrease firstly and then increase to a peak value, followed by a decrease to a low value in quasi-steady cavitation conditions. The dominant frequency of the outlet pressure pulsation is blade passing frequency whose amplitudes increase firstly and then decrease gradually with the decrease of NPSHa.

  17. Effects of Flow Rate and Viscosity on Slip Factor of Centrifugal Pump Handling Viscous Oils

    OpenAIRE

    Wen-Guang Li

    2013-01-01

    Slip factor is an important parameter in the hydraulic design of centrifugal pump impeller for handling viscous oils. How to extract the factor from CFD computational results and how flow rate and liquid viscosity to affect it remain unclear. In the present paper, the flip factor was estimated by means of two approaches: one is from the velocity triangles at the impeller outlet and the other is due to the impeller theoretical head of 3D turbulent viscous fluid. The velocity of water and visco...

  18. Numerical Simulation of Cavitation in a Centrifugal Pump at Low Flow Rate

    Institute of Scientific and Technical Information of China (English)

    TAN Lei; CAO Shu-Liang; WANG Yu-Ming; ZHU Bao-Shan

    2012-01-01

    Based on the full cavitation model which adopts homogeneous flow supposition and considering the compressibility effect on cavitation flow to modify the re-normalization group k-e turbulence model by the density function,a computational model is developed to simulate cavitation flow of a centrifugal pump at low flow rate.The NavierStokes equation is solved with the SIMPLEC algorithm.The calculated curves of net positive suction head available (NPSHa) HNPSHa agree well with the experimental data.The critical point of cavitation in centrifugal pump can be predicted precisely,and the NPSH critical values derived from simulation are consistent with the experimental data.Thus the veracity and reliability of this computational model are verified.Based on the result of numerical simulation,the distribution of vapor volume fraction in the impeller and pressure at the impeller inlet are analyzed.Cavities first appear on the suction side of the blade head near the front shroud.A large number of cavities block the impeller channels,which leads to the sudden drop of head at the cavitation critical point.With the reduction of NPSHa,the distribution of pressure at the impeller inlet is more uniform.%Based on the full cavitation model which adopts homogeneous Sow supposition and considering the compressibility effect on cavitation Row to modify the re-normalization group κ-ε turbulence model by the density function, a computational model is developed to simulate cavitation Bow of a centrifugal pump at low Bow rate. The Navier-Stokes equation is solved with the SIMPLEC algorithm. The calculated curves of net positive suction head available (NPSHa) Hnpshs agree well with the experimental data. The critical point of cavitation in centrifugal pump can be predicted precisely, and the NPSH critical values derived from simulation are consistent with the experimental data. Thus the veracity and reliability of this computational model are veriBed. Based on the result of numerical

  19. Numerical performance evaluation of design modifications on a centrifugal pump impeller running in reverse mode

    Science.gov (United States)

    Kassanos, Ioannis; Chrysovergis, Marios; Anagnostopoulos, John; Papantonis, Dimitris; Charalampopoulos, George

    2016-06-01

    In this paper the effect of impeller design variations on the performance of a centrifugal pump running as turbine is presented. Numerical simulations were performed after introducing various modifications in the design for various operating conditions. Specifically, the effects of the inlet edge shape, the meridional channel width, the number of blades and the addition of splitter blades on impeller performance was investigated. The results showed that, an increase in efficiency can be achieved by increasing the number of blades and by introducing splitter blades.

  20. The rotordynamic forces on a centrifugal pump impeller in the presence of cavitation

    Science.gov (United States)

    Franz, R.; Acosta, A. J.; Brennen, C. E.; Caughey, T. K.

    1990-01-01

    Fluid-induced rotordynamic forces on a centrifugal pump impeller whirling along a trajectory eccentric to its undeflected position in the presence of cavitation were measured using the experimental facility described by Jery (1987). The force measured is a combination of a steady radial force due to the volute asymmetries and an unsteady force due to the eccentric motion of the rotor. It was found that, compared to the noncavitation condition, a cavitation corresponding to a head loss of 3 percent had little effect upon the unsteady force. However, a lesser degree of cavitation at the design point, was found to increase the destabilizing force for a particular set of whirl ratios.

  1. Modeling erosion in a centrifugal pump in an Eulerian-Lagrangian frame using OpenFOAM®

    Science.gov (United States)

    Lopez, Alejandro; Stickland, Matthew; Dempster, William

    2015-07-01

    Erosion induced by solid particle impingement is a very commonwear mechanism in turbomachinery and Computational Fluid Dynamics is one of the most widely used tools for its prediction. In this article, erosion is modeled in one of the channels of a centrifugal pump using OpenFOAM®,which is an Open Source CFD package. A review of some of the most commonly used erosion models is carried out in an Eulerian-Lagrangian frame along with a comparative study of the erosion rates obtained with each model. Results yielded some disparities between models due to the different factors taken into consideration. The mesh is then deformed to obtain the resulting eroded geometry.

  2. Blood Pump Having a Magnetically Suspended Rotor

    Science.gov (United States)

    Antaki, James F. (Inventor); Paden, Bradley (Inventor); Burgreen, Gregory (Inventor); Groom, Nelson J. (Inventor)

    2002-01-01

    A blood pump preferably has a magnetically suspended rotor that rotates within a housing. The rotor may rotate about a stator disposed within the housing. Radial magnetic bearings may be defined within the stator and the rotor in order to suspend the rotor. The radial magnetic bearings may be passive magnetic bearings that include permanent magnets disposed within the stator and the rotor or active magnetic bearings. The pump may further include an axial magnetic bearing that may be either a passive or an active magnetic bearing. A motor that drives the rotor may be disposed within the housing in order to more easily dissipate heat generated by the motor. A primary flow path is defined between the rotor and the stator, and a secondary flow path is defined between the stator and the rotor. Preferably, a substantial majority of blood passes through the primary flow path. The secondary flow path is large enough so that it provides adequate flushing of the secondary flow path while being small enough to permit efficient operation of the radial magnet bearings across the secondary flow path.

  3. Power maximization of an asynchronous wind turbine with a variable speed feeding a centrifugal pump

    International Nuclear Information System (INIS)

    Highlights: • The pumping system studied contain a WT, a SEIG, an IM and a CP. • The system must ensure the water pumping in optimum conditions despite the wind speed. • A steady state study and a practical testing are performed to resolve the control law. • A MPPT is proposed on the basis of static converter SVC. - Abstract: This article focuses on the study of a pumping system compound of a wind turbine, a self-excited induction generator (SEIG), an induction motor (IM), and a centrifugal pump (CP), which aims to ensure the water pumping in optimum conditions regardless the wind speed. As a first step, a study in the steady and dynamic state to determine the control law is examined. As a second step, and so as to achieve a maximum energy flow we have proposed a Maximum Power Point Tracking (MPPT) algorithm based on a static converter SVC. As a final step, experimental and simulation results are discussed to show the reliability of the system proposed

  4. Numerical investigation of the effects of splitter blades on the cavitation performance of a centrifugal pump

    International Nuclear Information System (INIS)

    For the centrifugal pump, additional splitter blades are sometimes necessary in order to improve the head and efficiency. On the other hand, the additional splitter blades will have effect on the cavitation performance due to the changes at the impeller inlet channel. In order to investigate this influence, three impeller schemes were proposed based on a model pump IS50-32-160, one without splitter blades and another two with splitter blades of different inlet diameters. Numerical simulations were carried out to investigate the characteristics of internal flow and the pump cavitation performances at different NPSHA with the CFD technique. The results show that the additional splitter blades will have some positive effect on the pump cavitation performance if the inlet diameter of the splitter blade is properly selected. The reason behind such improvement is that it helps to avoid the flow blocking at the impeller inlet and the vortex cavitation inside the blade passages effectively. For the pump model under our investigation, the cavitation performance reaches its best when the inlet diameter of the splitter blade is 0.725D2

  5. Numerical investigation of the effects of splitter blades on the cavitation performance of a centrifugal pump

    Science.gov (United States)

    Zhang, Y. L.; Yuan, S. Q.; Zhang, J. F.; Feng, Y. N.; Lu, J. X.

    2014-03-01

    For the centrifugal pump, additional splitter blades are sometimes necessary in order to improve the head and efficiency. On the other hand, the additional splitter blades will have effect on the cavitation performance due to the changes at the impeller inlet channel. In order to investigate this influence, three impeller schemes were proposed based on a model pump IS50-32-160, one without splitter blades and another two with splitter blades of different inlet diameters. Numerical simulations were carried out to investigate the characteristics of internal flow and the pump cavitation performances at different NPSHA with the CFD technique. The results show that the additional splitter blades will have some positive effect on the pump cavitation performance if the inlet diameter of the splitter blade is properly selected. The reason behind such improvement is that it helps to avoid the flow blocking at the impeller inlet and the vortex cavitation inside the blade passages effectively. For the pump model under our investigation, the cavitation performance reaches its best when the inlet diameter of the splitter blade is 0.725D2.

  6. Cavitation in semi-open centrifugal impellers for a miniature pump

    Institute of Scientific and Technical Information of China (English)

    Xianwu LUO; Shuhong LIU; Yao ZHANG; Hongyuan XU

    2008-01-01

    Cavitation in miniature pumps was investi-gated experimentally for two semi-open centrifugal impellers. Although both impellers had the same blade cross-section, one impeller had a two-dimensional blade, while the other had a leaned blade. The flows were also analyzed using a numerical model of the three-dimen-sional turbulent flow in the pumps near the peak efficiency point using the k-ε turbulence model and the VOF cavitation model. The average cavitation perform-ance of each impeller was satisfactorily predicted by the numerical simulations. The results show that the miniature pumps have similar cavitation performances as an ordinary-size pump, with the cavitation perform-ance of the semi-open impeller reduced by increased axial tip clearances. Also, both the hydraulic and cavitation performance of the semi-open impeller were improved by the leaned blade. The results also show that uniform flow upstream of the impeller inlet will improve the cavitation performance of a miniature pump.

  7. Numerical Investigation on a Prototype Centrifugal Pump Subjected to Fluctuating Rotational Speed

    Directory of Open Access Journals (Sweden)

    Yu-Liang Zhang

    2014-01-01

    Full Text Available The rotational speed of pumps often encounters fluctuation in engineering for some reasons. In this paper, in order to study the transient response characteristic of a prototype centrifugal pump subjected to fluctuating rotational speed, a closed-loop pipe system including the pump is built to accomplish unsteady flow calculations in which the boundary conditions at the inlet and the outlet of the pump are not required to be set. The external performance results show that the head’s responsiveness to the fluctuating rotational speed is very good, while the flow rate’s responsiveness is slightly delayed. The variation tendencies of the static pressures at the inlet and the outlet of the pump are almost completely opposite, wherein the variation tendency of the static pressure at the outlet is identical with that of the rotational speed. The intensity of the turbulence energy in each impeller channel is relatively uniform in the transient flow calculations, while, in the quasi-steady flow calculation, it becomes weaker in a channel closed to the volute tongue. The nondimensional flow rate and head coefficients are dependent on the rotational speed, and their variation tendencies are opposite to that of the fluctuating rotational speed as a whole.

  8. Research on the effect of wear-ring clearances to the axial and radial force of a centrifugal pump

    International Nuclear Information System (INIS)

    Varying of the wear-ring clearance not only has a distinct effect on the volumetric loss of the centrifugal pump, but also on the performance of the centrifugal pump including the axial and radial forces. Comparing with the experimental studies, numerical simulation methods have some special advantages, such as the low cost, fast and high efficiency, and convenient to get the detailed structure of the internal flow characteristics, so it has been widely used in the fluid machinery study in recent years. In order to study the effect of wear-ring clearance on the force performance of the centrifugal pump, based on the Reynolds Time-Averaged N-S equations and RNG k-ε turbulence model, a centrifugal pump with three variable styles of the wear-rings was simulated: Only the clearance of the front wear-ring was changed, only the clearance of the back wear-ring was changed and both were changed. Comparing with the experiment, numerical results show a good agreement. In the three changing styles of the clearance, the variable of the clearance of front wear-ring has the most influence on the axial force of the centrifugal pump, while has tiny effect on the radial force for all the conditions

  9. Research on the effect of wear-ring clearances to the axial and radial force of a centrifugal pump

    Science.gov (United States)

    Zhao, W. G.; Y He, M.; Qi, C. X.; Li, Y. B.

    2013-12-01

    Varying of the wear-ring clearance not only has a distinct effect on the volumetric loss of the centrifugal pump, but also on the performance of the centrifugal pump including the axial and radial forces. Comparing with the experimental studies, numerical simulation methods have some special advantages, such as the low cost, fast and high efficiency, and convenient to get the detailed structure of the internal flow characteristics, so it has been widely used in the fluid machinery study in recent years. In order to study the effect of wear-ring clearance on the force performance of the centrifugal pump, based on the Reynolds Time-Averaged N-S equations and RNG k-ε turbulence model, a centrifugal pump with three variable styles of the wear-rings was simulated: Only the clearance of the front wear-ring was changed, only the clearance of the back wear-ring was changed and both were changed. Comparing with the experiment, numerical results show a good agreement. In the three changing styles of the clearance, the variable of the clearance of front wear-ring has the most influence on the axial force of the centrifugal pump, while has tiny effect on the radial force for all the conditions.

  10. Design and Simulation of Axial Flow Maglev Blood Pump

    OpenAIRE

    Huachun Wu; Ziyan Wang; Xujun Lv

    2011-01-01

    The axial flow maglev blood pump (AFMBP) has become a global research focus and emphasis for artificial ventricular assist device, which has no mechanical contact, mechanical friction, compact structure and light weight, can effectively solve thrombus and hemolysis. Magnetic suspension and impeller is two of the important parts in the axial flow maglev blood pump, and their structure largely determines the blood pump performance. The research adopts electromagnetic and fluid finite element an...

  11. Static stress and modal analysis on the impeller of screw centrifugal pump

    International Nuclear Information System (INIS)

    The modeling of the screw centrifugal pump was set up with Pro/E, the meshing of the fluid domain and the impeller were completed with ICEM, CFD and Workbench respectively. The 3-D steady turbulence flow in the pump was simulated by using ANSYS CFX under the design condition to get the pressure distribution on the surface of the blades. The static pressure and modal analysis were set using sequential coupling technique based on the simulation result. The results show that the maximum equivalent stress which is far less than the permissible stress occurs at the blade connected with the hub; the maximum deformation of the impeller occurs at the edge of the blade inlet; the deformation domain increase with the frequency ascended.

  12. The effect of inlet swirl on the rotordynamic shroud forces in a centrifugal pump

    Science.gov (United States)

    Ginzburg, A.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1992-01-01

    The role played by fluid forces in determining the rotordynamic stability of a centrifugal pump is gaining increasing attention. The present research investigates the contributions to the rotordynamic forces from the discharge-to-suction leakage flows between the front shroud of the rotating impeller and the stationary pump casing. In particular, the dependency of the rotordynamic characteristics of leakage flows on the swirl at the inlet to the leakage path was examined. An inlet guide vane was designed for the experiment so that swirl could be introduced at the leakage flow inlet. The data demonstrates substantial rotordynamic effects and a destabilizing tangential force for small positive whirl ratios; this force decreased with increasing flow rate. The effect of swirl on the rotordynamic forces was found to be destabilizing.

  13. EFFECTS OF SPLITTER BLADES ON THE LAW OF INNER FLOW WITHIN CENTRIFUGAL PUMP IMPELLER

    Institute of Scientific and Technical Information of China (English)

    YUAN Shouqi; ZHANG Jinfeng; YUAN Jianping; HE Youshi; FU Yuedeng

    2007-01-01

    Analysis on the inner flow field of a centrifugal pump impeller with splitter blades is carried out by numerical simulation. Based on this analysis, the principle of increasing pump head and efficiency are discussed. New results are obtained from the analysis of turbulence kinetic energy and relative velocity distribution: Firstly, unreasonable length or deviation design of the splitter blades may cause great turbulent fluctuation in impeller channel, which has a great effect on the stability of impeller outlet flow; Secondly, it is found that the occurrence of flow separation can be decreased or delayed with splitter blades from the analysis of blade loading; Thirdly, the effect of splitter blades on reforming the structure of "jet-wake" is explained from the relative velocity distribution at different flow cross-sections, which shows the flow process in the impeller. The inner flow analysis verifies the results of performance tests results and the PIV test.

  14. The effect of inlet swirl on the dynamics of long annular seals in centrifugal pumps

    Science.gov (United States)

    Ismail, M.; Brown, R. D.; France, D.

    1994-01-01

    This paper describes additional results from a continuing research program which aims to identify the dynamics of long annular seals in centrifugal pumps. A seal test rig designed at Heriot-Watt University and commissioned at Weir Pumps Research Laboratory in Alloa permits the identification of mass, stiffness, and damping coefficients using a least-squares technique based on the singular value decomposition method. The analysis is carried out in the time domain using a multi-fiequency forcing function. The experimental method relies on the forced excitation of a flexibly supported stator by two hydraulic shakers. Running through the stator embodying two symmetrical balance drum seals is a rigid rotor supported in rolling element bearings. The only physical connection between shaft and stator is the pair of annular gaps filled with pressurized water discharged axially. The experimental coefficients obtained from the tests are compared with theoretical values.

  15. Development of a pump flow estimator for rotary blood pumps to enhance monitoring of ventricular function.

    Science.gov (United States)

    Granegger, Marcus; Moscato, Francesco; Casas, Fernando; Wieselthaler, Georg; Schima, Heinrich

    2012-08-01

    Estimation of instantaneous flow in rotary blood pumps (RBPs) is important for monitoring the interaction between heart and pump and eventually the ventricular function. Our group has reported an algorithm to derive ventricular contractility based on the maximum time derivative (dQ/dt(max) as a substitute for ventricular dP/dt(max) ) and pulsatility of measured flow signals. However, in RBPs used clinically, flow is estimated with a bandwidth too low to determine dQ/dt(max) in the case of improving heart function. The aim of this study was to develop a flow estimator for a centrifugal pump with bandwidth sufficient to provide noninvasive cardiac diagnostics. The new estimator is based on both static and dynamic properties of the brushless DC motor. An in vitro setup was employed to identify the performance of pump and motor up to 20 Hz. The algorithm was validated using physiological ventricular and arterial pressure waveforms in a mock loop which simulated different contractilities (dP/dt(max) 600 to 2300 mm Hg/s), pump speeds (2 to 4 krpm), and fluid viscosities (2 to 4 mPa·s). The mathematically estimated pump flow data were then compared to the datasets measured in the mock loop for different variable combinations (flow ranging from 2.5 to 7 L/min, pulsatility from 3.5 to 6 L/min, dQ/dt(max) from 15 to 60 L/min/s). Transfer function analysis showed that the developed algorithm could estimate the flow waveform with a bandwidth up to 15 Hz (±2 dB). The mean difference between the estimated and measured average flows was +0.06 ± 0.31 L/min and for the flow pulsatilities -0.27 ± 0.2 L/min. Detection of dQ/dt(max) was possible up to a dP/dt(max) level of 2300 mm Hg/s. In conclusion, a flow estimator with sufficient frequency bandwidth and accuracy to allow determination of changes in ventricular contractility even in the case of improving heart function was developed. PMID:22882439

  16. On-site vibration fault diagnosis and solution measures of a centrifugal charging pump in nuclear power plant

    International Nuclear Information System (INIS)

    Vibration measurement of equipment during commissioning of nuclear power plants is one of important measures to ensure the plant safety. In this paper, through vibration measurement of the centrifugal charging pump during commission of a certain nuclear power plant, vibration fault of the pump is found. According to the signal features measured, faults of mass unbalance and uneven torque for the foundation bolts are diagnosed, and corresponding measures are implemented, which finally solve the vibration problem of this pump. The diagnosis process of the pump demonstrates that vibration faults of on-site equipment often have several causes, and even the same symptoms have different reasons. The vibration problem of the centrifugal charging pump in this paper is meaningful for solving practical engineering problems, and will provide important instructions and reference for disposing similar problems. (authors)

  17. Determination of Wear That Can be Formed at the Stainless Steel Wheels of the Centrifuge Pumps Used at Agricultural Irrigation

    Directory of Open Access Journals (Sweden)

    E. Yuksel

    2009-09-01

    Full Text Available The extent of this work is operating characteristics of a horizontal shafted centrifugal pump (which has stainless steel wheel which has been operated for 7 hours on the average. A closed circuit pump system (circulating within itself which was formed by attaching a horizontal shafted centrifugal pump which can be used in irrigation applications with a drum has been operated for 150 hours at laboratory conditions. To define the operating properties of the pump, its operating characteristics were measured in respect to ISO 2548. Furthermore, observations have been done to determine whether there is a connection between operating characteristics of the pump and the wear and corrosion occured on the wheel or not.

  18. Stress Analysis of the Centrifugal Pump Pipe%离心泵管道应力浅析

    Institute of Scientific and Technical Information of China (English)

    江浩

    2014-01-01

    结合离心泵管口受力要求及应力分析原则,分析与探讨如何建立离心泵管道应力计算模型,涉及泵的模拟、管道计算温度的选取、泵与储罐之间的柔性连接,以及泵管口受力和力矩的控制途径等。%Combine the force requirements and stress principles of the centrifugal pump pipe nozzle ,analyze and discuss how to establish the stress calculation model of the centrifugal pump ,w hich including the pump simulation ,pipe calculated temperature option , flexible connection between the pump and tank ,and control ways for pump pipe nozzle force and moment of force .

  19. Predicting performance of radial flow type impeller of centrifugal pump using CFD

    International Nuclear Information System (INIS)

    The main objective of this work is to use the computational fluid dynamics (CFD) technique in analyzing and predicting the performance of a radial flow-type impeller of centrifugal pump. The impeller analyzed is at the following design condition: flow rate of 528 m3/hr: speed of 1450 rpm: and head of 20 m or specific speed (Ns) of 3033 1/min in US-Units. The first stage involves the mesh generation and refinement on domain of the designed impeller. The second stage deals with the identification of initial and boundary conditions of the mesh-equipped module. In the final stage, various results are calculated and analyzed for factors affecting impeller performance. The results indicate that the total head rise of the impeller at the design point is approximately 19.8 m. The loss coefficient of the impeller is 0.015 when 0.6 < Q/Qdesign < 1.2. Maximum hydraulic efficiency of impeller is 0.98 at Q/Qdesign = 0.7. Based on the comparison of the theoretical head coefficient and static pressure rise coefficient between simulation results and experimental data, from previous work reported in the literature [Guelich, Kreiselpumpen, Springer, Berlin, 2004], it is possible to use this method to simulate the performance of a radial-flow type impeller of a centrifugal pump

  20. Numerical Simulation of Cavitation in a Centrifugal Pump at Low Flow Rate

    International Nuclear Information System (INIS)

    Based on the full cavitation model which adopts homogeneous flow supposition and considering the compressibility effect on cavitation flow to modify the re-normalization group k-in turbulence model by the density function, a computational model is developed to simulate cavitation flow of a centrifugal pump at low flow rate. The Navier-Stokes equation is solved with the SIMPLEC algorithm. The calculated curves of net positive suction head available (NPSHa) HNPSHa agree well with the experimental data. The critical point of cavitation in centrifugal pump can be predicted precisely, and the NPSH critical values derived from simulation are consistent with the experimental data. Thus the veracity and reliability of this computational model are verified. Based on the result of numerical simulation, the distribution of vapor volume fraction in the impeller and pressure at the impeller inlet are analyzed. Cavities first appear on the suction side of the blade head near the front shroud. A large number of cavities block the impeller channels, which leads to the sudden drop of head at the cavitation critical point. With the reduction of NPSHa, the distribution of pressure at the impeller inlet is more uniform. (fundamental areas of phenomenology(including applications))

  1. Suppression of the secondary flow in a suction channel of a large centrifugal pump

    International Nuclear Information System (INIS)

    The suction channel configuration of a large centrifugal pump with a 90-degree bend was studied in detail to suppress the secondary flow at the impeller inlet for improving suction performance. Design of experiments (DOE) and computational fluid dynamics (CFD) were used to evaluate the sensitivity of several primary design parameters of the suction channel. A DOE is a powerful tool to clarify the sensitivity of objective functions to design parameters with a minimum of trials. An L9 orthogonal array was adopted in this study and nine suction channels were designed, through which the flow was predicted by steady state calculation. The results indicate that a smaller bend radius with a longer straight nozzle, distributed between the bend and the impeller, suppresses the secondary flow at the impeller inlet. An optimum ratio of the cross sectional areas at the bend inlet and outlet was also confirmed in relationship to the contraction rate of the downstream straight nozzle. These findings were obtained by CFD and verified by experiments. The results will aid the design of large centrifugal pumps with better suction performance and higher reliability

  2. Application of modified k-ω model to predicting cavitating flow in centrifugal pump

    Directory of Open Access Journals (Sweden)

    Hou-lin LIU

    2013-07-01

    Full Text Available Considering the compressibility of the cavity in the cavitating flow, this paper presents a modified k-ω model for predicting the cavitating flow in a centrifugal pump, in which the modified k-ω model and Schnerr-Sauer cavitation model were combined with ANSYS CFX. To evaluate the modified and standard k-ω models, numerical simulations were performed with these two models, respectively, and the calculation results were compared with the experimental data. Numerical simulations were executed with three different values of the flow coefficient, and the simulation results of the modified k-ω model showed agreement with most of the experimental data. The cavitating flow in the centrifugal pump obtained by the modified k-ω model at the design flow coefficient of 0.102, was analyzed. When the cavitation number decreases, the cavity initially generates on the suction side of the blade near the leading edge and then expands to the outlet of the impeller, and the decrease of the total pressure coefficient mainly occurs upstream of the impeller passage, while the downstream remains almost unaffected by the development of cavitation.

  3. Numerical Investigations of Unsteady Flow in a Centrifugal Pump with a Vaned Diffuser

    Directory of Open Access Journals (Sweden)

    Olivier Petit

    2013-01-01

    Full Text Available Computational fluid dynamics (CFD analyses were made to study the unsteady three-dimensional turbulence in the ERCOFTAC centrifugal pump test case. The simulations were carried out using the OpenFOAM Open Source CFD software. The test case consists of an unshrouded centrifugal impeller with seven blades and a radial vaned diffuser with 12 vanes. A large number of measurements are available in the radial gap between the impeller and the diffuse, making this case ideal for validating numerical methods. Results of steady and unsteady calculations of the flow in the pump are compared with the experimental ones, and four different turbulent models are analyzed. The steady simulation uses the frozen rotor concept, while the unsteady simulation uses a fully resolved sliding grid approach. The comparisons show that the unsteady numerical results accurately predict the unsteadiness of the flow, demonstrating the validity and applicability of that methodology for unsteady incompressible turbomachinery flow computations. The steady approach is less accurate, with an unphysical advection of the impeller wakes, but accurate enough for a crude approximation. The different turbulence models predict the flow at the same level of accuracy, with slightly different results.

  4. Numerical simulation of cavitation effects influenced by centrifugal pump inlet parameters

    Science.gov (United States)

    Zhao, L. F.; Wang, Y.; Ning, C.; Liu, Z. C.; Zhu, Z. T.; Xie, S. F.

    2015-01-01

    Cavitation has great influence on performance of the centrifugal pump. However, there is still no effective design to overcome this problem. Blade leading edge of centrifugal pump impeller is the initial position of cavitation. The leading edge geometry shape not only has a great influence on the cavitation inception and its development, but also a great influence on the flow state near the impeller inlet. In this paper, the numerical simulation method is adopted. Cavitation of four different models (including rectangular-shape blade model, circular-arc-shape blade model, elliptical-shape blade model and cusp-shape blade model) are simulated under the same condition by changing the NPSHA value. The influence of different blade models on cavitation performance is analyzed. The results show that the deviation between the simulated data and experimental data is within the deviation range. The head of rectangular-shape blade model and circular-arc-shape blade model are higher than those of elliptical-shape blade model and cusp-shape blade model. However, the head of rectangular-shape blade model and circular-arc-shape blade model is smaller than the latter under the low effective cavitation margin. What's more, the head of the models with trimmed blade are higher than the head of the models with untrimmed blade under the working condition but are smaller under the low effective cavitation margin.

  5. Analysis of silt abrasion of the impeller ring in a centrifugal pump with J-grooves

    Science.gov (United States)

    Qian, Z. D.; Wang, Z. Y.; Guo, Z. W.; Dong, J.; Lu, J.

    2016-05-01

    The water flow and movement of silt in a prototype double-suction centrifugal pump was simulated using an Euler-Lagrange multiphase flow model. J-Grooves were adopted to protect the impeller ring from silt abrasion. The influence of J-grooves on the silt concentration and pump efficiency was analyzed. The results show that the radial component of the relative velocity around the impeller ring is too low to move the silt out of the spacing between the impeller plate and the casing. The high silt concentration around the impeller ring is the major contributor to silt abrasion of the impeller ring. The J-grooves induce two strong vortices, which increase the radial component of the relative velocity of water and reduce the silt concentration around the impeller ring, but additional friction losses are introduced and the pump efficiency is decreased. Optimization of the number and shape of J-grooves decreases losses in the efficiency of the pump, and effectively protects the impeller ring. Case 4 was found the most effective configuration in this study.

  6. Experimental and numerical study of transient flow in a centrifugal pump during startup

    International Nuclear Information System (INIS)

    Transient characteristics and flows in a centrifugal pump during its starting period were experimentally and numerically investigated. The two-dimensional particle image velocimetry technique was used to capture transient flow evolutions in the pump's diffuser. A new dynamic slip region method that combines the dynamic mesh method with the non-conformal grid boundaries is proposed to resolve the transient flows caused by the started impeller. Numerical self-coupling was realized by establishing a circulation pipe system along with the pump model equivalent to the experimental pump system. Numerical and experimental results agree well in both explicit characteristics and internal transient flow structures, confirming the validity of the proposed method. Analysis of the instantaneous flow in the impellers indicates that for the early stage of the startup, the transient vortex evolution between blades is the main reason for the transient head coefficient being lower than the steady state value. The reversed flow at the blade inlet is a less important reason for this effect. In later stages, the weakening of the intensity of the spatial vortex visible on S2m and the main flow stream are the main reasons for the explicit performance slowly rebounding to the steady value

  7. Feedback Control and Dynamic Behaviour of Z-Source Converter Fed Separately Excited DC Motor and Centrifugal Pump Set

    Directory of Open Access Journals (Sweden)

    Saswati Swapna Dash

    2014-07-01

    Full Text Available This paper presents an overall study of Feedback Control of Z-Source Converter Fed Separately excited DC motor with centrifugal Pump Set. Z-source converter can be used for both voltage buck and boost mode using LC impedance network. In this paper the dynamic modeling of Z-source with motor load and centrifugal pump set is carried out with new findings. The compensators for speed feedback loop are designed by taking average state space analysis and small signal model of the system. The feedback loop is designed by classical control methods. The experiment is done in MATLAB work environment and the result is verified by Simulation.

  8. Research on Three-Dimensional Unsteady Turbulent Flow in Multistage Centrifugal Pump and Performance Prediction Based on CFD

    OpenAIRE

    Zhi-jian Wang; Jian-she Zheng; Lu-lu Li; Shuai Luo

    2013-01-01

    The three-dimensional flow physical model of any stage of the 20BZ4 multistage centrifugal pump is built which includes inlet region, impeller flow region, guide-vane flow region and exit region. The three-dimensional unsteady turbulent flow numerical model is created based on Navier-Stoke solver and standard k-ε turbulent equations. The method of multireference frame (MRF) and SIMPLE algorithm are used to simulate the flow in multistage centrifugal pump based on FLUENT software. The distribu...

  9. Feedback Control and Dynamic Behaviour of Z-Source Converter Fed Separately Excited DC Motor and Centrifugal Pump Set

    OpenAIRE

    Saswati Swapna Dash; Byamakesh Nayak; Subrat Kumar

    2014-01-01

    This paper presents an overall study of Feedback Control of Z-Source Converter Fed Separately excited DC motor with centrifugal Pump Set. Z-source converter can be used for both voltage buck and boost mode using LC impedance network. In this paper the dynamic modeling of Z-source with motor load and centrifugal pump set is carried out with new findings. The compensators for speed feedback loop are designed by taking average state space analysis and small signal model of the system. The feedba...

  10. Unsteady numerical simulation for gas–liquid two-phase flow in self-priming process of centrifugal pump

    International Nuclear Information System (INIS)

    Highlights: • The transient gas–liquid two-phase flow fields in the self-priming centrifugal pump are simulated. • The self-priming time and performance are estimated. • The air void fraction and two phase distribution are obtained.· The hole on the volute plays a significant role for gas exhausting. • The frequency of the impulsive pressure basically conforms to that of the air exhausted out of the pump. - Abstract: Self-priming pumps start up without pre-irrigation, and then work as common pumps when air in the pump is exhausted. The transient gas–liquid flow at the start-up stage inside a self-priming pump is an interesting process which greatly influences performance of the pump. In this paper, a conventional vertical self-priming centrifugal pump was selected as the object. Using unsteady numerical simulation, the authors investigated the transient gas–liquid two-phase flow in the self-priming centrifugal pump during the self-priming process. The main innovation in the simulation was that a section of the suction pipe filled with air was set as the initial condition, which conformed to the actual self-priming conditions. The gas–liquid two-phase distribution, the pressure and velocity in relation to time were computed and analyzed. Flow rates of both phases with time at the pump inlet and outlet were obtained based on the simulation, which could be used to estimate the self-priming time and other performance parameters. Finally, the numerical method and results for gas–liquid two-phase flow in the self-priming pump was partly validated by the pump performance test

  11. Research of factors influencing centrifugal pump external characteristics based on orthogonal test

    International Nuclear Information System (INIS)

    In order to investigate the impact on external characteristics of single-stage and single-suction centrifugal pump, four parameters: cutwater gap(δ), blade number(z), impeller outlet width(b) and blade outlet angle(β) were taken into account. Orthogonal test method is a method which can make a comprehensive comparison among factors we are interested in. Thereby, it can't be more appropriate to adopt this approach to study the influence of the four factors referred above. Based on the prototype pump's geometric parameters, each of these factors took four levels. According to the principle of selecting orthogonal array, the L16(45) array was selected and 16 models were designed. After that, commercial CFD software CFX was used to calculate the head and efficiency under different conditions to determine the optimal operating condition Qr. The 16 models' rated flow rates were basically smaller than the prototype's. Considering this difference, in order to analyze the influence on the head under similar condition, the flow rate was made dimensionless and 3 conditions are chosen(Qr/Q=1, 1.25 and 1.375). Through the analysis of averaged respond head and efficiency, the laws of head and efficiency changing with the variation of the factors were obtained. Commonly, if a dependent's change cause by a independent variable is smaller than 5%, we can neglect the independent variable's effect. Thus the paper presents a research showing the factors' changing limitations considering the head changing by a percentage smaller than 5%. The conclusion of this article has important reference value for design of centrifugal pumps

  12. Parametric study of blade tip clearance, flow rate, and impeller speed on blood damage in rotary blood pump.

    Science.gov (United States)

    Kim, Nahn Ju; Diao, Chenguang; Ahn, Kyung Hyun; Lee, Seung Jong; Kameneva, Marina V; Antaki, James F

    2009-06-01

    Phenomenological studies on mechanical hemolysis in rotary blood pumps have provided empirical relationships that predict hemoglobin release as an exponential function of shear rate and time. However, these relations are not universally valid in all flow circumstances, particularly in small gap clearances. The experiments in this study were conducted at multiple operating points based on flow rate, impeller speed, and tip gap clearance. Fresh bovine red blood cells were resuspended in phosphate-buffered saline at about 30% hematocrit, and circulated for 30 min in a centrifugal blood pump with a variable tip gap, designed specifically for these studies. Blood damage indices were found to increase with increased impeller speed or decreased flow rate. The hemolysis index for 50-microm tip gap was found to be less than 200-microm gap, despite increased shear rate. This is explained by a cell screening effect that prevents cells from entering the smaller gap. It is suggested that these parameters should be reflected in the hemolysis model not only for the design, but for the practical use of rotary blood pumps, and that further investigation is needed to explore other possible factors contributing to hemolysis. PMID:19473143

  13. Research of fluid-induced pressure fluctuation due to impeller-volute interaction in a centrifugal pump

    International Nuclear Information System (INIS)

    The fluid pressure fluctuation generated by unsteady flow is a very important factor to induce vibration of the centrifugal pump. The relative movement between impeller and volute generates an unsteady interaction which affects not only the overall pump performance, but is also responsible for pressure fluctuations. Pressure fluctuations interact with the volute casing or even with the circuit and give rise to dynamic effects over the mechanical parts, which are one of the most important sources of vibration and hydraulic noise. To investigate the flow characteristic in the centrifugal pump, the unsteady flow is simulated by CFD methods in this paper. Unsteady flow characteristic in the centrifugal pump is obtained considering the impeller-volute interaction in the whole flow field. Based on the unsteady flow simulation, amplitude-frequency characteristics of the pressure fluctuation in the centrifugal pump are obtained through setting up monitoring point at the impeller outlet. The research shows that the frequency component include the blade passing frequency as the main component, the multiplication of blade passing frequency, and the harmonic interference due to the unsteady flow

  14. Research of fluid-induced pressure fluctuation due to impeller-volute interaction in a centrifugal pump

    Science.gov (United States)

    Liu, Q. Z.; Yang, K.; Y Li, D.; Gong, R. Z.

    2013-12-01

    The fluid pressure fluctuation generated by unsteady flow is a very important factor to induce vibration of the centrifugal pump. The relative movement between impeller and volute generates an unsteady interaction which affects not only the overall pump performance, but is also responsible for pressure fluctuations. Pressure fluctuations interact with the volute casing or even with the circuit and give rise to dynamic effects over the mechanical parts, which are one of the most important sources of vibration and hydraulic noise. To investigate the flow characteristic in the centrifugal pump, the unsteady flow is simulated by CFD methods in this paper. Unsteady flow characteristic in the centrifugal pump is obtained considering the impeller-volute interaction in the whole flow field. Based on the unsteady flow simulation, amplitude-frequency characteristics of the pressure fluctuation in the centrifugal pump are obtained through setting up monitoring point at the impeller outlet. The research shows that the frequency component include the blade passing frequency as the main component, the multiplication of blade passing frequency, and the harmonic interference due to the unsteady flow.

  15. ICDE project report on collection and analysis of common-cause failures of centrifugal pumps

    International Nuclear Information System (INIS)

    Several member countries of OECD/NEA decided to establish the International Common-Cause Failure Data Exchange (ICDE) Project to encourage multilateral co-operation in the collection and analysis of data relating to Common-Cause Failure (CCF) events. The project was initiated in August 1994 in Sweden and was discussed at meetings in both Sweden and France in 1995. A coding benchmark exercise was defined which was evaluated at meetings held in Germany and in the US in 1996. Subsequently, the exchange of centrifugal pump data was defined; the first phase of this exchange was evaluated at meetings in Switzerland and in France in 1997. The objectives of the ICDE Project are: - to collect and analyse CCF events in the long term so as to better understand such events, their causes, and their prevention, - to generate qualitative insights into the root causes of CCF events which can then be used to derive approaches or mechanisms for their prevention or for mitigating their consequences, - to establish a mechanism for the efficient feedback of experience gained on CCF phenomena, including the development of defences against their occurrence, such as indicators for risk based inspections. The ICDE Project is envisaged as including all possible events of interest, comprising complete, partial and incipient CCF events, called 'ICDE events' in the following. The Project covers the key components of the main safety systems, like centrifugal pumps, diesel generators, motor operated valves, power operated relief valves, safety relief valves, check valves, RPS circuit breakers, batteries and transmitters. Data are collected in an MS ACCESS based databank implemented and maintained at ES-Konsult, Sweden, by NEA appointed clearinghouse. The databank is regularly updated. The clearinghouse and the project group operate it. In the modelling of common-cause failures in systems consisting of several redundant components, two kinds of events are distinguished: a) Unavailability of a

  16. Effect of blade outlet angle on radial thrust of single-blade centrifugal pump

    Science.gov (United States)

    Nishi, Y.; Fukutomi, J.; Fujiwara, R.

    2012-11-01

    Single-blade centrifugal pumps are widely used as sewage pumps. However, a large radial thrust acts on a single blade during pump operation because of the geometrical axial asymmetry of the impeller. This radial thrust causes vibrations of the pump shaft, reducing the service life of bearings and shaft seal devices. Therefore, to ensure pump reliability, it is necessary to quantitatively understand the radial thrust and clarify the behavior and generation mechanism. This study investigated the radial thrust acting on two kinds of single-blade centrifugal impellers having different blade outlet angles by experiments and computational fluid dynamics (CFD) analysis. Furthermore, the radial thrust was modeled by a combination of three components, inertia, momentum, and pressure, by applying an unsteady conservation of momentum to this impeller. As a result, the effects of the blade outlet angle on both the radial thrust and the modeled components were clarified. The total head of the impeller with a blade outlet angle of 16 degrees increases more than the impeller with a blade outlet angle of 8 degrees at a large flow rate. In this case, since the static pressure of the circumference of the impeller increases uniformly, the time-averaged value of the radial thrust of both impellers does not change at every flow rate. On the other hand, since the impeller blade loading becomes large, the fluctuation component of the radial thrust of the impeller with the blade outlet angle of 16 degrees increases. If the blade outlet angle increases, the fluctuation component of the inertia component will increase, but the time-averaged value of the inertia component is located near the origin despite changes in the flow rate. The fluctuation component of the momentum component becomes large at all flow rates. Furthermore, although the time-averaged value of the pressure component is almost constant, the fluctuation component of the pressure component becomes large at a large flow rate

  17. Numerical and experimental studies of hydraulic noise induced by surface dipole sources in a centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    刘厚林; 戴菡葳; 丁剑; 谈明高; 王勇; 黄浩钦

    2016-01-01

    The influences of the four different surface dipole sources in a centrifugal pump on the acoustic calculating accuracy are studied in this paper, by using the CFD combined with the Lighthill acoustic analogy methods. Firstly, the unsteady flow in the pump is solved based on the large eddy simulation method and the pressure pulsations on the four different surfaces are obtained. The four surfaces include the volute surface, the discharge pipe surface, the inner surface of the pump cavity, and the interfaces between the impeller and the stationary parts as well as the outer surface of the impeller. Then, the software Sysnoise is employed to interpolate the pressure fluctuations onto the corresponding surfaces of the acoustic model. The Fast Fourier Transform with a Hanning window is used to analyze the pressure fluctuations and transform them into the surface dipole sources. The direct boundary element method is applied to calculate the noise radiated from the dipole sources. And the predicted sound pressure level is compared with the experi- mental data. The results show that the pressure fluctuations on the discharge pipe surface and the outer surface of the impeller have little effect on the acoustic simulation results. The pressure pulsations on the inner surface of the pump cavity play an important role in the internal flow and the acoustic simulation. The acoustic calculating error can be reduced by about 7% through considering the effect of the pump cavity. The sound pressure distributions show that the sound pressure level increases with the growing flow rate, with the largest magnitude at the tongue zone.

  18. Analysis on the blade inlet pressure fluctuation of the centrifugal pump based on LES

    International Nuclear Information System (INIS)

    In order to study the characteristics of the blade inlet pressure fluctuation under unsteady flow in centrifugal pump, a three-dimensional model of a pump ns=50 was built. Based on large eddy simulation (LES), the inner flow field of the pump was simulated by the flow field simulation software Fluent in design condition and off-design conditions. The pressure fluctuation of the monitored points was obtained at the blade suction surface and pressure surface at impeller inlet, which was analyzed by time and frequency domain with Fast Fourier Transformation (FFT). The results show that the pressure fluctuation of inlet and outlet in large flow rate is more obvious than low flow rate. It is easily found that the static pressure of outlet in 1.2Qd condition has five peaks and five valleys, but this phenomenon does not exist in 0.6 Qd condition. In the time domain spectrums, the static pressure curve has five peaks and five valleys that the maximum pressure is positive number and the minimum pressure is negative number. In the frequency domains spectrums, the frequency of FFT factors peak is lower than the blade passing frequency 241.65Hz

  19. Analysis on the blade inlet pressure fluctuation of the centrifugal pump based on LES

    Science.gov (United States)

    Wang, W. J.; Cui, Y. R.; Wang, Y.; Li, G. D.; Liang, Q. H.; Yin, G.

    2013-12-01

    In order to study the characteristics of the blade inlet pressure fluctuation under unsteady flow in centrifugal pump, a three-dimensional model of a pump ns=50 was built. Based on large eddy simulation (LES), the inner flow field of the pump was simulated by the flow field simulation software Fluent in design condition and off-design conditions. The pressure fluctuation of the monitored points was obtained at the blade suction surface and pressure surface at impeller inlet, which was analyzed by time and frequency domain with Fast Fourier Transformation (FFT). The results show that the pressure fluctuation of inlet and outlet in large flow rate is more obvious than low flow rate. It is easily found that the static pressure of outlet in 1.2Qd condition has five peaks and five valleys, but this phenomenon does not exist in 0.6 Qd condition. In the time domain spectrums, the static pressure curve has five peaks and five valleys that the maximum pressure is positive number and the minimum pressure is negative number. In the frequency domains spectrums, the frequency of FFT factors peak is lower than the blade passing frequency 241.65Hz.

  20. Experimental study of unsteady hydrodynamic force matrices on whirling centrifugal pump impellers. Ph.D. Thesis

    Science.gov (United States)

    Belgacem, Jery

    1986-01-01

    An experimental facility was constructed and instrumented. A set of centrifugal flow pumps whose impellers were made to follow a controlled circular whirl motion were studied. The aim was to characterize the steady and unsteady fluid forces measured on the impeller under various pump operating conditions. The postulation was that the unsteady lateral forces result from interactions between the impeller and the surrounding diffuser and/or volute (via the working fluid), and that under certain flow regimes these forces can drive unstable lateral motions of the pump rotor. The lateral hydrodynamic forces were decomposed into their steady and unsteady parts, the latter being further expressed in terms of a generalized fluid stiffness matrix. Conclusions regarding the effect of impeller geometry could not be reached given the similarity of the tested designs. However, other results on phenomena such as skin friction and leakage flow are presented. Some of the findings are compared to experimental and theoretical data from other sources. Finally, the rotordynamic consequences of the results are discussed as the present data were applied to the case of the Space Shuttle Main Engine (SSME) High Pressure Oxidizer Turbopump (HPOTP).

  1. Multi-objective optimization of a low specific speed centrifugal pump using an evolutionary algorithm

    Science.gov (United States)

    An, Zhao; Zhounian, Lai; Peng, Wu; Linlin, Cao; Dazhuan, Wu

    2016-07-01

    This paper describes the shape optimization of a low specific speed centrifugal pump at the design point. The target pump has already been manually modified on the basis of empirical knowledge. A genetic algorithm (NSGA-II) with certain enhancements is adopted to improve its performance further with respect to two goals. In order to limit the number of design variables without losing geometric information, the impeller is parametrized using the Bézier curve and a B-spline. Numerical simulation based on a Reynolds averaged Navier-Stokes (RANS) turbulent model is done in parallel to evaluate the flow field. A back-propagating neural network is constructed as a surrogate for performance prediction to save computing time, while initial samples are selected according to an orthogonal array. Then global Pareto-optimal solutions are obtained and analysed. The results manifest that unexpected flow structures, such as the secondary flow on the meridian plane, have diminished or vanished in the optimized pump.

  2. THREE-DIMENSIONAL COUPLED IMPELLER-VOLUTE SIMULATION OF FLOW IN CENTRIFUGAL PUMP AND PERFORMANCE PREDICTION

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A three-dimensional turbulent flow through an entire centrifugal pump is simulated using k-ε turbulence model modified by rotation and curvature, SIMPLEC method and body-fitted coordinate. The velocity and pressure fields are obtained for the pump under various working conditions, which is used to predict the head and hydraulic efficiency of the pump, and the results correspond well with the measured values. The calculation results indicate that the pressure is higher on the pressure side than that on the suction side of the blade; The relative velocity on the suction side gradually decreases from the impeller inlet to the outlet, while increases on the pressure side, it finally results in the lower relative velocity on the suction side and the higher one on the pressure side at the impeller outlet; The impeller flow field is asymmetric, i.e. the velocity and pressure fields are totally different among all channels in the impeller; In the volute, the static pressure gradually increases with the flow route, and a large pressure gratitude occurs in the tongue; Secondary flow exists in the rear part of the spiral.

  3. Effect of Blade Outlet Angle on Unsteady Hydrodynamic Force of Closed-Type Centrifugal Pump with Single Blade

    OpenAIRE

    Yasuyuki Nishi; Junichiro Fukutomi

    2014-01-01

    Geometrically, the single-blade centrifugal impeller, commonly used today as a sewage pump, is not axially symmetric. For this reason, the static pressure around the impeller fluctuates greatly when the impeller is rotating, and not only the radial thrust but also the axial thrust shows large fluctuations. Therefore, it is extremely important for the improvement of pump reliability to quantitatively grasp these fluctuating hydrodynamic forces. In this study, we investigated the unsteady hydro...

  4. Numerical Investigation of a First Stage of a Multistage Centrifugal Pump: Impeller, Diffuser with Return Vanes, and Casing

    OpenAIRE

    Nicolas La Roche-Carrier; Guyh Dituba Ngoma; Walid Ghie

    2013-01-01

    This paper deals with the numerical investigation of a liquid flow in a first stage of a multistage centrifugal pump consisting of an impeller, diffuser with return vanes, and casing. The continuity and Navier-Stokes equations with the k-ε turbulence model and standard wall functions were used. To improve the design of the pump's first stage, the impacts of the impeller blade height and diffuser vane height, number of impeller blades, diffuser vanes and diffuser return vanes, and wall roughne...

  5. Exploration of hemolytic model of axial blood pump

    OpenAIRE

    Miao Song; Yu Chang; Yanjiao Xuan

    2012-01-01

    Axial flow blood pumps provides additional energy to blood for heart failure patient, but its implanting destroy environment of blood cells, the direct consequence is hemolysis. According to energy conservation theorem, the severity of pump hemolysis depends on the energy utilization ratio of it. This is a new train of thought in this field. In the light of it, it¡¯s necessary to clear up how much energy used to pump blood, so part of the rest is the energy leading to hemolysis. At present, a...

  6. Simulation and experiment of the effect of clearance of impeller wear-rings on the performance of centrifugal pump

    International Nuclear Information System (INIS)

    The effect of clearance of impeller wear-rings on the performance of a centrifugal pump was investigated numerically and experimentally. The whole flow field model including front and back shrouds of pump was designed so as to accurately calculate the head and efficiency of the centrifugal pump. Based on RNG k-ε turbulence model, three wear-rings schemes were established, and the effects of clearance of impeller wear-rings on the hydraulic efficiency and mechanical efficiency of the centrifugal pump was analyzed, chiefly from the turbulent kinetic energy, vorticity and radial force angles. According to the results, it can be drawn that the head and total efficiency of the centrifugal pump increase as the clearance value of wear-rings narrows. The following reasons may account for it: firstly, as the clearance value of wear-rings declines, the turbulent kinetic energy and energy dissipation decrease within the impeller, and the impact of secondary flow at the inlet of impeller on the mainstream weakens slowly, which leads to a lower hydraulic loss, thus a higher hydraulic efficiency; secondly, radial force decreases with the clearance value of wear-rings, so the eccentric whirl of centrifugal pump is dampened, which results in a lower mechanical loss and a higher mechanical efficiency; thirdly, the front shroud leakage diminishes with the clearance value of wear-rings, therefore, the volume loss is reduced and volume efficiency improved. Finally, the first wear-ring scheme of impeller is adopted after comprehensive comparison of these three wear-ring schemes, because its efficiency is highest and it satisfies the requirements of the engineering application.

  7. Numerical and experimental study on flow-induced noise at blade-passing frequency in centrifugal pumps

    Science.gov (United States)

    Yang, Jun; Yuan, Shouqi; Yuan, Jianping; Si, Qiaorui; Pei, Ji

    2014-05-01

    With the increasing noise pollution, low noise optimization of centrifugal pimps has become a hot topic. However, experimental study on this problem is unacceptable for industrial applications due to unsustainable cost. A hybrid method that couples computational fluid dynamics (CFD) with computational aeroacoustic software is used to predict the flow-induced noise of pumps in order to minimize the noise of centrifugal pumps in actual projects. Under Langthjem's assumption that the blade surface pressure is the main flow-induced acoustic source in centrifugal pumps, the blade surface pressure pulsation is considered in terms of the acoustical sources and simulated using CFX software. The pressure pulsation and noise distribution in the near-cutoff region are examined for the blade-passing frequency (BPF) noise, and the sound pressure level (SPL) reached peaks near the cutoff that corresponded with the pressure pulsation in this region. An experiment is performed to validate this prediction. Four hydrophones are fixed to the inlet and outlet ports of the test pump to measure the flow-induced noise from the four-port model. The simulation results for the noise are analyzed and compared with the experimental results. The variation in the calculated noise with changes in the flow agreed well with the experimental results. When the flow rate was increased, the SPL first decreased and reached the minimum near the best efficient point (BEP); it then increased when the flow rate was further increased. The numerical and experimental results confirmed that the BPF noise generated by a blade-rotating dipole roughly reflects the acoustic features of centrifugal pumps. The noise simulation method in current study has a good feasibility and suitability, which could be adopted in engineering design to predict and optimize the hydroacoustic behavior of centrifugal pumps.

  8. Hydrodynamic impeller stiffness, damping, and inertia in the rotordynamics of centrifugal flow pumps

    Science.gov (United States)

    Jery, S.; Acosta, A. J.; Brennen, C. E.; Caughey, T. K.

    1984-01-01

    The lateral hydrodynamic forces experienced by a centrifugal pump impeller performing circular whirl motions within several volute geometries were measured. The lateral forces were decomposed into: (1) time averaged lateral forces and (2) hydrodynamic force matrices representing the variation of the lateral forces with position of the impeller center. It is found that these force matrices essentially consist of equal diagonal terms and skew symmetric off diagonal terms. One consequence of this is that during its whirl motion the impeller experiences forces acting normal and tangential to the locus of whirl. Data on these normal and tangential forces are presented; it is shown that there exists a region of positive reduced whirl frequencies, within which the hydrodynamic forces can be destablizing with respect to whirl.

  9. Numerical simulation and uncertainty estimation in a deep-well centrifugal pump

    International Nuclear Information System (INIS)

    One stage deep-well centrifugal pump section is investigated numerically in this study. Three-dimensional steady Reynolds-Averaged Navier–Stokes (RANS) equations are solved on high-quality fine structured grids in conjunction with the shear stress transport (SST) k-ω turbulence model by employing the CFD (computational fluid dynamics) software ANSYS-Fluent 13.0. A detailed grid sensitivity analysis was carried out to analyse the influence of grid elements number. The discretization errors were calculated specifically through the Richardson extrapolation theory. The uncertainty of fine gird for the simulation in this paper was estimated as 1.23%. The prototype experimental test results were acquired and compared with the data predicted from the numerical simulation, which showed that there is a good agreement between two methods

  10. Pressure Fluctuation in a Vaned Diffuser Downstream from a Centrifugal Pump Impeller

    Directory of Open Access Journals (Sweden)

    Akinori Furukawa

    2003-01-01

    Full Text Available Periodic flows downstream from a centrifugal pump impeller in vaneless and vaned diffusers were measured by using a single hole yawmeter and a phase-locked sampling method. The flows were also calculated by an inviscid flow analysis using the blade-surface singularity method. The periodic variations in calculated static pressure with the impeller rotating quantitatively agree well with the measured ones. The flow behaviors in the vaned diffuser are discussed, citing measured and calculated results. The potential interaction between the impeller and the diffuser blades appears more strongly than the impeller-wake interaction. The appearance of static pressure fluctuations due to the impeller's rotating in the fully vaned zone is different from that in the semivaned zone of the diffuser. The existence of the peripheral blade surface of the impeller outlet with an outlet edge of the pressure surface causes violent pressure fluctuations in the vaned diffuser.

  11. Experimental research on internal flow in impeller of a low specific speed centrifugal pump by PIV

    Science.gov (United States)

    Zhang, J. F.; Wang, Y. F.; Yuan, S. Q.

    2016-05-01

    For the purpose of investigating the influence of two different impellers, one is with splitter blades and the other one is without splitter blades, on a low-specific centrifugal pump. The experimental investigation in impellers was conducted at different conditions and phases by means of PIV (Particle Image Velocimetry) to study the internal flow. Meanwhile, the absolute and relative velocity distributions in impellers were obtained. Experimental results show that the head value is higher in the impeller with splitter blades and both two head curves appear hump phenomena at small flow rate. The absolute velocity value increases with radius and from pressure side to suction side at the same radius gradually. The splitter blades can scour the wake, making outlet velocity distribution more uniform and improving the internal flow. The velocity distribution becomes less even in the process of closing to tongue due to reinforced interference of tongue on internal flow.

  12. Annular Seals of High Energy Centrifugal Pumps: Presentation of Full Scale Measurement

    Science.gov (United States)

    Florjancic, S.; Stuerchler, R.; Mccloskey, T.

    1991-01-01

    Prediction of rotordynamic behavior for high energy concentration centrifugal pumps is a challenging task which still imposes considerable difficulties. While the mechanical modeling of the rotor is solved most satisfactorily by finite element techniques, accurate boundary conditions for arbitrary operating conditions are known for journal bearings only. Little information is available on the reactive forces of annular seals, such as neck ring and interstage seals and balance pistons, and on the impeller interaction forces. The present focus is to establish reliable boundary conditions at annular seals. For this purpose, a full scale test machine was set up and smooth and serrated seal configurations measured. Dimensionless coefficients are presented and compared with a state of the art theory.

  13. Study on the influence of back blade shape on the wear characteristics of centrifugal slurry pump

    Science.gov (United States)

    Cai, X.; Zhou, S. P.; Li, S.

    2016-05-01

    CFX particle inhomogeneous model was introduced for the mechanism analysis of a centrifugal slurry pump which is equipped with back blades on impeller shrouds. Combining with the total efficiency correction, the simulation showed good prediction accuracy of external characteristics results compared with the experimental values. Vorticity and Q-Criterion were chosen as the variables to illustrate the abrasion morphology and wear mechanism by contrasting simulation result with worn impeller in engineering. The analysis showed that the large vorticity intensity areas are distributed at the edge of impeller shroud and intensively behind the back blades. Moreover, the vorticity scattered on suction surface of back blade shows the largest intensity. The contour of Q-Criterion demonstrated that the swirl scale in front cavity is obviously larger than that in back cavity. The distribution of vorticity on both front and back shrouds can reasonably explain the impeller wear characteristics. Finally, the forward curved back blade proved to be excellence performance in vorticity distribution.

  14. On the inverse problem of blade design for centrifugal pumps and fans

    International Nuclear Information System (INIS)

    The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated. (paper)

  15. On the inverse problem of blade design for centrifugal pumps and fans

    Science.gov (United States)

    Kruyt, N. P.; Westra, R. W.

    2014-06-01

    The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated.

  16. MANAGING CENTRIFUGAL PUMP RELIABILITY IN THE CONTEXT OF TOTAL COST OF OWNERSHIP

    Directory of Open Access Journals (Sweden)

    J. Van der Poel

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: The management of a population of centrifugal pumps in the petrochemical industry can be daunting. A popular method for strategically optimizing the maintenance and operation of these centrifugal pumps is to measure the reliability of the whole pump population in terms of Mean-Time-Between-Failures (MTBF. Too often MTBF improvement becomes the focus rather than a means of supporting the actual goal, namely Total Cost of Ownership (TCO reduction. An increase in MTBF is intuitively associated with a reduction of TCO, but this is not necessarily true. This study proposes that the ‘MTBF vs time’ and ‘TCO vs MTBF’ curves are characteristics of a specific industrial plant. A tool for approximating the optimum TCO vs MTBF for a plant is introduced, and a qualitative framework for managing pump reliability in the TCO context is proposed.

    AFRIKAANSE OPSOMMING: Die bestuur van ’n sentrifugale pomppopulasie in die petrochemiese bedryf kan oorweldigend wees. ’n Populêre metode om die instandhouding en bedryf van hierdie sentrifugale pompe op ’n strategiese vlak te optimiseer, is om die betroubaarheid van die pomppopulasie in geheel, in terme van Gemiddelde-Tyd- Tussen-Falings (GTTF, te meet. Die fokus word te veel op die verbetering van die GTTF geplaas en nie op die eintlike doel, naamlik die vermindering van Totale Koste van Eienaarskap (TKE nie. ‘n Verbetering in die GTTF word intuïtief geassosieer met ’n vermindering van TKE, maar dit is nie noodwendig waar nie. Hierdie studie stel voor dat die ‘GTTF vs Tyd’-kurwe en ‘TKE vs GTTF’-kurwe kenmerkend is van ’n spesifieke industriële aanleg. ’n Instrument om die benaderde optimum TKE vs GTTF vir ’n aanleg te bepaal, asook ‘n kwalitatiewe raamwerk om pomp betroubaarheid in die TKE konteks te bestuur, word voorgestel.

  17. Research on the blood pump for extracorporeal circulation%体外循环用血泵研究进展

    Institute of Scientific and Technical Information of China (English)

    路力军; 胡兆燕; 陈正龙; 潘友联

    2012-01-01

    This paper describes the principle and clinical significance of extracorporeal circulation, briefly introduces the principles and characteristics of the blood pump for extracorporeal circulation, and the key technical evaluation indexes of the blood pump. The paper focuses on the development history of centrifugal blood pump, the working principle and features of the second-generation, the third-generation magnetic drive blood pump. The second-generation blood pump uses disc-shaped magnetic coupler whose permanent magnet adopts the structure of push-pull combination. The third-generation blood pump based on the second one is added the suspension system, including electromagnetic levitation and permanent magnetic levitation at present. Finally this paper prospects for the development trend of the centrifugal blood pump for extracorporeal circulation.%本文在阐述体外循环原理及临床意义的基础上,简单介绍了体外循环用血泵的原理、特点以及关键技术评价指标,重点分析了离心血泵的发展历史,及二代、三代离心血泵磁力驱动的工作原理和特点.第二代血泵采用圆盘形磁力耦合器驱动方式,其永磁体采用组合拉推式结构.第三代血泵是在第二代血泵的基础上增加了磁悬浮系统.最后展望了体外循环用离心血泵的发展趋势.

  18. Hydraulic Calculation Method for the Fluid Delivery System of Centrifugal Pump%离心泵流体输送系统水力计算方法

    Institute of Scientific and Technical Information of China (English)

    徐宏斌

    2001-01-01

    简述离心泵和管路的特性,介绍离心泵流体输送管路系统的水力计算方法,以及如何确定泵的安装高度。%The characteristics of centrifugal pump and pipeline are brieflyelaborated. The hydraulic calculation method for fluid delivery pipeline system of centrifugal pump and the method of determining the pump installation height are introduced.

  19. Effects of outlet blade angle of centrifugal pump on the pump performance under air-water two-phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Minemura, Kiyoshi; Kinoshita, Katsuhiko [Nagoya Univ. (Japan). School of Informatics and Sciences; Ihara, Masaru; Furukawa, Hironori; Egashira, Kazuyuki [Japan National Oil Corp., Chiba (Japan). Petroleum Engineering Lab.

    1995-12-31

    To establish the optimum design parameters of offshore oil well centrifugal pumps, which should deliver crude oil containing a large amount of gas, various shapes of pump impeller with different outlet blade angles, locations of leading-edge and numbers of impeller blades as the design parameters were tested with various rotating speeds and suction pressures under air-water two-phase flow conditions. The greater the outlet blade angle, the less the degradation of the pump performance becomes, showing the optimum blade angle approximately equals to 90{degree}.

  20. Numerical research on the cavitation characteristics for typical conditions of a centrifugal pump with whole flow passage

    Science.gov (United States)

    Cao, L.; Wang, Z. W.; Xiao, Y. X.; Yao, Y. Y.; Zhu, W.

    2015-01-01

    Cavitation is one of the key issues affecting the safe and stable operation of centrifugal pumps. This research conducted numerical simulations of the 3-D turbulent flow in the whole flow passage of a centrifugal pump using RANS method. The calculation results of cavitation characteristics agreed well with the experimental results, which were based on SST k-ω turbulence model and Zwart-Gerber-Belamri cavitation model. This paper analysed the cavitation development process and the corresponding pump performance for three typical conditions, namely large discharge condition, design discharge condition and small discharge condition, by changing the available Net Positive Suction Head (NPSHa). For large discharge condition, the incipient NPSHa was large, while for design discharge condition and small discharge condition, the incipient NPSHa values were almost the same and both small. As the flow rate decreased, the critical NPSHa decreased as well, and the cavitation positons gradually shift from the pressure surfaces of some blades to the suction surfaces. At the same time, the tongue has greater effect with larger flow rate and the cavitation becomes less unsteady with the decrease of flow rate. With similar vapour volume, cavitation on the blade pressure side more easily leads to the drop of pump performance. Therefore, more attention should be paid to the cavitation characteristics of centrifugal pumps in large flow conditions in hydraulic design stage.

  1. Flow measurements in a model centrifugal pump by 3-D PIV

    Science.gov (United States)

    Yang, H.; Xu, H. R.; Liu, C.

    2012-11-01

    PIV (Particle Image Velocimetry), as an non-intrusive flow measurements technology, is widely used to investigate the flow fields in many areas. 3-D (three Dimensional) PIV has seldom been used to measure flow field in rotational impeller of centrifugal pump due to the difficulty of calibration in samll space. In this article, a specially manufactured water tank was used to perform the calibration for 3-D PIV measurement. The instantaneous absolute velocity in one impeller passage was obtained by merging of three sub zones and the relative velocity was acquired by velocity decomposition. The result shows that, when the pump runs at the condition of design flow rate, the radial component velocity Wr appears a concave distribution except the condition of R=45 mm. With the increase of radius, the circumference location of the minimum radial component velocity Wr moves from the pressure side to the suction side. At the same time, the tangential component velocity Wθ on the suction side decreases gradually with the increase of radius, while the component on the pressure side increases gradually. The secondary flow in different radius section has also been shown. At last, the error of PIV measurements was analyzed, which shows that the test results are accurate and the measured data is reliable.

  2. Numerical simulation and performance prediction in multi-stage submersible centrifugal pump

    International Nuclear Information System (INIS)

    In order to study the inner flow field of multi-stage submersible centrifugal pump, the model named QD3-60/4-1.1 was selected. Steady turbulence characteristics of impellers, diffusers and return channel were calculated by Fluent software, the SIMPLEC algorithm and RNG κ-ε turbulence model with sliding mesh technology. Then, the distributions of pressure, velocity and Turbulence kinetic energy was obtained and the distributions of velocity field of a channel were analysed. The results show that the static pressure in impeller is increasing with the increasing of radius. The circumferential component of relative velocity is in the opposite direction of impeller rotating. At the same radius, the component value of pressure surface is larger than suction surface. With the increasing of flow rate, absolute velocity and relative velocity flow angle are becoming small, in opposite of the relative velocity and absolute velocity flow angle. The high turbulent zone of impeller is located in the gap of impellers and diffusers. Flow similarity and structure similarity of the multi-stage submersible pump are confirmed

  3. Study on Improving Suction Performance of Centrifugal Pump in Pump Well%改善机井离心泵吸水性能的研究

    Institute of Scientific and Technical Information of China (English)

    刘建华; 尚四青

    2014-01-01

    针对河南省清丰县某井灌区由于机井水位下降而造成机井离心泵无法正常工作的问题,对离心泵进行了全面的检测,并结合该井灌区的相关水文资料以及井、泵的性能参数分析,提出了改造离心泵以改善机井离心泵吸水性能的措施,即利用射流技术改善机井离心泵吸水性能。根据井、泵参数设计了射流装置,通过灌区应用,达到了预期目标,该方案为灌溉设备的改造提供了有效的参考。%We did comprehensive test on centrifugal pump ,because water level dropped in a well irrigation area of Qingfeng country in Henan ,which made the centrifugal pump working abnormally .The measure for transforming centrifugal pump ,which was jet flow technology ,to improve suction performance of the shaft centrifugal pump were put forward ,after analyzing the related hydrological data of this area and performance parameters of the well and pump .So we designed a fluidic device according to the performance parameters of well and pump ,and application reached the expected goal .The scheme provides effective reference for reconstruction of irrigation equipment .

  4. Mechanical Blood Pumps for Cardiac Assistance

    Directory of Open Access Journals (Sweden)

    M. Akdis

    2005-01-01

    Full Text Available Cardiac assist devices are classified into the traditional engineering categories of displacement and rotary pumps. Clinical use and indications of the various pump categories are outlined and a detailed description of currently available systems is given. The first part deals with extracorporeal as well as implantable ventricular assist devices (VAD of the displacement type and is followed by a section on current developments in the field of total artificial hearts (TAH. The second part covers the rotary pump category from cardiopulmonary bypass applications to implantable systems, including specific design aspects of radial, diagonal, and axial pumps.

  5. Numerical research on the effects of impeller pump-out vanes on axial force in a solid-liquid screw centrifugal pump

    International Nuclear Information System (INIS)

    A commercial CFD code has been used to predict the performance of a screw centrifugal pump with pump-out vanes, especially when changing regularity of impeller axial force based on the solid-liquid two-phase flow. The Unsteady Reynolds Averaged Navier-Stokes (URANS) approach has been applied to solve the unsteady, incompressible, three-dimensional turbulent. The SIMPLEC algorithm, standard wall functions and mix two-phase flow model were applied. The RNG k ε-model was used to account the turbulence effects. By changing the number of impeller pump-out vanes and width, six different screw centrifugal pump numerical simulation projects were given, and each scheme in the different solid volume fraction were calculated respectively. The change rules of axial force, velocity and pressure distribution of flow field were obtained on the different condition and different volume fraction. The results showed that the axial forces values based solid-fluid two-phase greater than based single-phase clear water, but both changing regularity of the axial force were consistent; as same condition, the same solid-phase volume concentration, with the increase of pump-out vanes number or width, the impeller axial force increased as well. Meanwhile the number of the pump-out vanes and the width of pump-out vanes in balancing the impeller axial force, there are the most optimal value

  6. Numerical research on the effects of impeller pump-out vanes on axial force in a solid-liquid screw centrifugal pump

    Science.gov (United States)

    Cheng, X. R.; Li, R. N.; Gao, Y.; Guo, W. L.

    2013-12-01

    A commercial CFD code has been used to predict the performance of a screw centrifugal pump with pump-out vanes, especially when changing regularity of impeller axial force based on the solid-liquid two-phase flow. The Unsteady Reynolds Averaged Navier-Stokes (URANS) approach has been applied to solve the unsteady, incompressible, three-dimensional turbulent. The SIMPLEC algorithm, standard wall functions and mix two-phase flow model were applied. The RNG k ε-model was used to account the turbulence effects. By changing the number of impeller pump-out vanes and width, six different screw centrifugal pump numerical simulation projects were given, and each scheme in the different solid volume fraction were calculated respectively. The change rules of axial force, velocity and pressure distribution of flow field were obtained on the different condition and different volume fraction. The results showed that the axial forces values based solid-fluid two-phase greater than based single-phase clear water, but both changing regularity of the axial force were consistent; as same condition, the same solid-phase volume concentration, with the increase of pump-out vanes number or width, the impeller axial force increased as well. Meanwhile the number of the pump-out vanes and the width of pump-out vanes in balancing the impeller axial force, there are the most optimal value.

  7. Assessment of hydraulic performance and biocompatibility of a MagLev centrifugal pump system designed for pediatric cardiac or cardiopulmonary support.

    Science.gov (United States)

    Dasse, Kurt A; Gellman, Barry; Kameneva, Marina V; Woolley, Joshua R; Johnson, Carl A; Gempp, Thomas; Marks, John D; Kent, Stella; Koert, Andrew; Richardson, J Scott; Franklin, Steve; Snyder, Trevor A; Wearden, Peter; Wagner, William R; Gilbert, Richard J; Borovetz, Harvey S

    2007-01-01

    The treatment of children with life-threatening cardiac and cardiopulmonary failure is a large and underappreciated public health concern. We have previously shown that the CentriMag is a magnetically levitated centrifugal pump system, having the utility for treating adults and large children (1,500 utilized worldwide). We present here the PediVAS, a pump system whose design was modified from the CentriMag to meet the physiological requirements of young pediatric and neonatal patients. The PediVAS is comprised of a single-use centrifugal blood pump, reusable motor, and console, and is suitable for right ventricular assist device (RVAD), left ventricular assist device (LVAD), biventricular assist device (BVAD), or extracorporeal membrane oxygenator (ECMO) applications. It is designed to operate without bearings, seals and valves, and without regions of blood stasis, friction, or wear. The PediVAS pump is compatible with the CentriMag hardware, although the priming volume was reduced from 31 to 14 ml, and the port size reduced from 3/8 to (1/4) in. For the expected range of pediatric flow (0.3-3.0 L/min), the PediVAS exhibited superior hydraulic efficiency compared with the CentriMag. The PediVAS was evaluated in 14 pediatric animals for up to 30 days, demonstrating acceptable hydraulic function and hemocompatibility. The current results substantiate the performance and biocompatibility of the PediVAS cardiac assist system and are likely to support initiation of a US clinical trial in the future. PMID:18043164

  8. 离心泵的性能特点及应用研究%Performance characteristics and Application Research of centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    徐志鹏

    2016-01-01

    In the production of petroleum and petrochemical,the application of centrifugal pump is very wide,so the application of centrifugal pump is of great significance. This paper briefly introduces the performance characteristics of centrifugal pump,centrifugal pump selection and energy saving,centrifugal pump installation,centrifugal pump and the failure of the centrifugal pump and the elimination measures are discussed and analyzed in detail.%在石油和石化生产中,离心泵的应用非常广泛,因此对离心泵的应用研究具有重要意义。文中介绍了离心泵的性能特点,从离心泵的选型、离心泵的安装、离心泵的运行以及离心泵的故障及排除措施等几个方面进行了详细的论述和分析。

  9. Development of miniaturized mass flow meter for an axial flow blood pump.

    Science.gov (United States)

    Kosaka, Ryo; Maruyama, Osamu; Nishida, Masahiro; Yamane, Takashi

    2007-05-01

    To grasp the conditions of patients and implantable artificial hearts, it is essential to monitor the blood flow rate continuously and noninvasively. However, it is difficult to monitor the pump flow rate in an implantable artificial heart, because the conventional flow meter is too large to implant into the human body, and the flow estimation method is influenced by changes in the blood characteristics and the pump performance. In particular, the power consumption has neither linearity nor uniqueness with respect to the pump flow rate in an axial flow blood pump. In this research, we develop a prototype miniaturized mass flow meter that uses centrifugal force F(c) for discharged patients with an axial flow blood pump. This flow meter measures the F(c) corresponding to the mass flow rate, and implements compensation for static pressure. Because the strain gauges are attached outside of the curved tube, this mass flow meter has no blood contact point, resulting in a compact design. To evaluate the measurement accuracy and the tracking performance, the mass flow meter was compared with the conventional ultrasonic flow meter in a mock-up circulation study. As a result, the measurement error ranging from 0.5 to 5.0 L/min was less than +/-10% with respect to the maximum flow rate. The tracking performance of pulsation flow was approximately equivalent to that of the conventional flow meter. These experiments demonstrated that the prototype miniaturized mass flow meter using F(c) could accurately measure the mass flow rate continuously and noninvasively. PMID:17470214

  10. 离心泵故障诊断及实例分析%Fault Diagnosis and Case Analysis of Centrifugal Pumps

    Institute of Scientific and Technical Information of China (English)

    侯志广

    2014-01-01

    With the actual operation state of the centrifugal pumps at Qianan Steel as the background and through taking examples, the typical faults of centrifugal pumps and treatment solutions during operation process are analyzed, to provide reference for fault diag-nosis of centrifugal pumps.%以迁钢离心泵的实际运行情况为背景,通过举例分析了离心泵在工作过程中的典型故障及解决方案,为离心泵故障的诊断提供参考。

  11. Studies of the impact of prerotation problem of the secondary impeller on performance of multi-stage centrifugal pumps

    International Nuclear Information System (INIS)

    In engineering practice, part of the multi-stage centrifugal pumps is designed without space guide vanes due to the size restrictions and the volute is distorted much in shape. In these pumps, tangential velocity of the fluid at the outlet of the first-stage impeller is so great that it has caused a prerotation problem which will affect the inlet flow conditions of the secondary impeller leading to serious efficiency and head decline of the secondary impeller. The head problem of the second stage in multi-stage centrifugal pumps caused by prerotation at the entrance of the second stage was analyzed and the internal hydraulic performance was optimized by setting clapboards in the volute in this paper. CFD numerical simulation method combined with experiment was applied to predict the effect of internal clapboards on the performance of the centrifugal pump. The original prototype was transformed according to the simulation result and tested to verify the optimization work. The experiment result shows that hydraulic performance is remarkably improved compared with the original one and the prerotation problem is basically solved.

  12. Studies on the Influence of Various Blade Outlet Angles in a Centrifugal Pump when Handling Viscous Fluids

    Directory of Open Access Journals (Sweden)

    M. H.S. Fard

    2007-01-01

    Full Text Available In this study the centrifugal pump performances with different blade outlet angles are tested when handling water and viscous oils as Newtonian fluids. Also, this study shows a numerical simulation of the three-dimensional fluid flows inside the centrifugal pump with different blade outlet angles. For these numerical simulations the SIMPLEC algorithm is used for solving governing equations of incompressible viscous/turbulent flows through the pump at different operating conditions. The k-ε turbulence model is adopted to describe the turbulent flow process. These simulations have been made with a steady calculation using the multiple reference frames (MRF technique to take into account the impeller- volute interaction. Numerical results are compared with the experimental characteristic curve for each viscous fluid. The results show that when the outlet angle increases, the centrifugal pump performance handling viscous fluids improves. This improvement is due to decrease of wake at the exit of impeller. Also the results show that the well-known jet/wake flow model is not found in the impeller simulations.

  13. Effects of radial diffuser hydraulic design on a double-suction centrifugal pump

    Science.gov (United States)

    Hou, H. C.; Zhang, Y. X.; Xu, C.; Zhang, J. Y.; Li, Z. L.

    2016-05-01

    device and is good to transform the dynamic energy to pressure energy. Then through the hydraulic loss analysis of each pump component for all diffusers, it shows that the impeller takes up the biggest part of the whole loss about 8.19% averagely, the radial diffuser about 3.70% and the volute about 1.65%. The hydraulic loss of impeller is dominant at the large flow rate while the radial diffuser is at the small flow rate. Among all diffusers, the ES profile diffuser generates the least loss and combined to the distribution of velocity vector and turbulent kinetic energy for two kinds of diffusers it also shows that ES profile is fit to apply in radial diffuser. This research can offer a significant reference for the radial diffuser hydraulic design of such centrifugal pumps.

  14. Mechanical Blood Pumps for Cardiac Assistance

    OpenAIRE

    Akdis, M; Reul, H

    2005-01-01

    Cardiac assist devices are classified into the traditional engineering categories of displacement and rotary pumps. Clinical use and indications of the various pump categories are outlined and a detailed description of currently available systems is given. The first part deals with extracorporeal as well as implantable ventricular assist devices (VAD) of the displacement type and is followed by a section on current developments in the field of total artificial hearts (TAH). The second part co...

  15. Analysis of the effect of hydrophobic properties of surfaces in the flow part of centrifugal pumps on their operational performance

    Science.gov (United States)

    Volkov, A. V.; Parygin, A. G.; Lukin, M. V.; Ryzhenkov, A. V.; Khovanov, G. P.; Naumov, A. V.; Soukal, J.; Pochyly, F.; Fialova, S.

    2015-11-01

    The results of experimental studies focused on evaluating the effect of different conditions of wetting of functional surfaces in flow parts of centrifugal pumps (specifically, impellers) used in heat- and watersupply systems on their operational performance are presented. The conditions of interaction of the pumped medium with the impeller surfaces were altered through hydrophobization of functional surfaces that was implemented using the techniques developed at the Moscow Power Engineering Institute and the Brno University of Technology. It is demonstrated that this hydrophobization produced a considerable positive effect and raised the efficiency of pump units based on centrifugal KM pumps of three different form factors produced by ZAO Pompa (Shchelkovo) and a K centrifugal pump produced by Sigma. The efficiency was increased by 2-6% depending on the pump model. The results of experimental studies of the effect of hydrophobization of the surface of a canonical plate-type domain with a working medium flowing longitudinally along it in a hydrodynamic bed (Moscow Power Engineering Institute) are detailed. Two flat plates with a length of 250 mm and a width of 252 mm were studied. The surfaces of these plates had different roughness values, since one of the plates was polished prior to hydrophobization. Different wetting conditions, which were monitored by measuring the contact angle with a KRUSS MobileDrop goniometer, were established after hydrophobization. The obtained experimental data showed that the surface friction of the modified plate with a higher initial roughness (unpolished plate) was reduced by as much as 23%. This result agrees completely with the Cassie hypothesis.

  16. Fluid-Structure Interaction Analysis on Turbulent Annular Seals of Centrifugal Pumps during Transient Process

    Directory of Open Access Journals (Sweden)

    Qinglei Jiang

    2011-01-01

    Full Text Available The current paper studies the influence of annular seal flow on the transient response of centrifugal pump rotors during the start-up period. A single rotor system and three states of annular seal flow were modeled. These models were solved using numerical integration and finite difference methods. A fluid-structure interaction method was developed. In each time step one of the three annular seal models was chosen to simulate the annular seal flow according to the state of rotor systems. The objective was to obtain a transient response of rotor systems under the influence of fluid-induced forces generated by annular seal flow. This method overcomes some shortcomings of the traditional FSI method by improving the data transfer process between two domains. Calculated results were in good agreement with the experimental results. The annular seal was shown to have a supportive effect on rotor systems. Furthermore, decreasing the seal clearance would enhance this supportive effect. In the transient process, vibration amplitude and critical speed largely changed when the acceleration of the rotor system increased.

  17. Numerical investigation of sediment erosion to the impeller in a double-suction centrifugal pump

    International Nuclear Information System (INIS)

    Based on Euler-Lagrange multiphase flow model and Finnie ductile material erosion model, using phase coupled SIMPLE algorithm, k-e RNG turbulence model and Reynolds Averaged Navier-Stokes (RANS) equation, the solid-liquid two-phase flows in a double-suction centrifugal pump is simulated. The erosion rate and solid mass concentration distribution on the pressure and suction surfaces of blades were obtained in different situations, which include different solid mass concentration (2.17kg/m3, 8.66kg/m3 and 14kg/m3) and different sediment diameter (0.019mm, 0.036mm, and 0.076mm). By comparisons of the test and numerical simulation values, the reliability of numerical calculation method has been verified. The numerical simulation result obtained show that the Finnie ductile material erosion model can accurately predict the erosion rate and erosion areas on the impeller. The erosion rate is increases with solid sediment diameter or solid mass concentration increasing. The main erosion areas on the pressure surface of blades near the blade inlet and outlet and close to the hub, and on the suction surface of blades near the blade inlet and close to the hub. For different sediment diameter or solid mass concentration, the erosion rate on the pressure surface of blades is always greater than that on its suction surface

  18. Numerical investigation of sediment erosion to the impeller in a double-suction centrifugal pump

    Science.gov (United States)

    Yang, C. X.; Dong, F. D.; Cheng, X. R.

    2013-12-01

    Based on Euler-Lagrange multiphase flow model and Finnie ductile material erosion model, using phase coupled SIMPLE algorithm, k-e RNG turbulence model and Reynolds Averaged Navier-Stokes (RANS) equation, the solid-liquid two-phase flows in a double-suction centrifugal pump is simulated. The erosion rate and solid mass concentration distribution on the pressure and suction surfaces of blades were obtained in different situations, which include different solid mass concentration (2.17kg/m3, 8.66kg/m3 and 14kg/m3) and different sediment diameter (0.019mm, 0.036mm, and 0.076mm). By comparisons of the test and numerical simulation values, the reliability of numerical calculation method has been verified. The numerical simulation result obtained show that the Finnie ductile material erosion model can accurately predict the erosion rate and erosion areas on the impeller. The erosion rate is increases with solid sediment diameter or solid mass concentration increasing. The main erosion areas on the pressure surface of blades near the blade inlet and outlet and close to the hub, and on the suction surface of blades near the blade inlet and close to the hub. For different sediment diameter or solid mass concentration, the erosion rate on the pressure surface of blades is always greater than that on its suction surface.

  19. Multicondition Optimization and Experimental Measurements of a Double-Blade Centrifugal Pump Impeller.

    Science.gov (United States)

    Liu, Houlin; Wang, Kai; Yuan, Shouqi; Tan, Minggao; Wang, Yong; Dong, Liang

    2013-01-01

    In order to improve internal unsteady flow in a double-blade centrifugal pump (DBCP), this study used major geometric parameters of the original design as the initial values, heads at three conditions (i.e., 80% design flow rate, 100% design flow rate, and 120% design flow rate) as the constraints conditions, and the maximum of weighted average efficiency at the three conditions as the objective function. An adaptive simulated annealing algorithm was selected to solve the energy performance calculation model and the supertransitive approximation method was applied to fix optimal weight factors of individual objectives. On the basis of hydraulic performance optimization, three-condition automatic computational fluid dynamics (CFD) optimization of impeller meridional plane for the DBCP was realized by means of Isight software integrated Pro/E, Gambit, and Fluent software. The shroud arc radii R0 and R1, shroud angle T1, hub arc radius R2, and hub angle T2 on the meridional plane were selected as the design variables and the maximum of weighted average hydraulic efficiency at the three conditions was chosen as the objective function. Performance characteristic test and particle image velocimetry (PIV) measurements of internal flow in the DBCP were conducted. Performance characteristic test results show that the weighted average efficiency of the impeller after the three-condition optimization has increased by 1.46% than that of original design. PIV measurements results show that vortex or recirculation phenomena in the impeller are distinctly improved under the three conditions. PMID:23917426

  20. Modal Analysis of a Centrifugal Pump Impeller Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Ashri Muhammad

    2014-07-01

    Full Text Available The turbo machinery design has evolved rapidly in the last 50 years. The development in the design of any turbo machinery involves interdisciplinary process, namely stress analysis, vibration analysis, fluid dynamics, thermodynamics and the material selection. One of the major and common analyses used in the development of any mechanical part subjected to dynamic loading is the modal analysis. In this paper, the dynamic characteristics of an impeller of a centrifugal pump were studied. The dynamics characteristics studied were limited to the natural frequencies and the mode shapes. The impeller chosen for the study was a single-entry impeller with radial vanes. Finite element method (FEM was used since it has proven to be an alternative approach to the experimental method for the vibrational behavior analysis of a component or a system. Modeling and simulation of the impeller have been carried out using ANSYS Bladegen and ANSYS Workbench software, respectively. The eigenvalues and the eigenvectors were observed, and they represent the frequencies and the corresponding mode shapes of the impeller, respectively. The results showed that the varying number of impeller blades and impeller blade thickness had minimal effect on frequencies. However, the change to the impeller disk thickness had significant effects on the natural frequency of the impeller.

  1. Effects of Flow Rate and Viscosity on Slip Factor of Centrifugal Pump Handling Viscous Oils

    Directory of Open Access Journals (Sweden)

    Wen-Guang Li

    2013-01-01

    Full Text Available Slip factor is an important parameter in the hydraulic design of centrifugal pump impeller for handling viscous oils. How to extract the factor from CFD computational results and how flow rate and liquid viscosity to affect it remain unclear. In the present paper, the flip factor was estimated by means of two approaches: one is from the velocity triangles at the impeller outlet and the other is due to the impeller theoretical head of 3D turbulent viscous fluid. The velocity of water and viscous oils in the impeller and volute computed by CFD was validated with LDV measurements at the best efficiency point. The effect of exit blade angle on slip factor was clarified. It was shown that the two approaches result into two different slip factors. The factors are significantly dependent of flow rate; however, the liquid viscosity seems to take less effect on them. Volute is responsible for reduction in tangential velocity of liquid at the outlet of impeller at low flow rates. The slip factor of impeller with large exit blade angle is not sensitive to flow rate.

  2. Numerical Identification of Key Design Parameters Enhancing the Centrifugal Pump Performance: Impeller, Impeller-Volute, and Impeller-Diffuser

    OpenAIRE

    Djerroud, Massinissa; Dituba Ngoma, Guyh; Ghie, Walid

    2011-01-01

    This paper presents the numerical investigation of the effects that the pertinent design parameters, including the blade height, the blade number, the outlet blade angle, the blade width, and the impeller diameter, have on the steady state liquid flow in a three-dimensional centrifugal pump. Three cases were considered for this study: impeller, combined impeller and volute, and combined impeller and diffuser. The continuity and Navier-Stokes equations with the k-ε turbulence model and the sta...

  3. 对矿用离心式水泵的操作和维护分析%Analysis of Operation and Maintenance of Mining Centrifugal Pumps

    Institute of Scientific and Technical Information of China (English)

    景忠玉

    2016-01-01

    在矿井建设和生产过程中,离心式水泵承担着排水的重要任务,正确使用以及维护离心式水泵对于矿井的安全生产起着决定性作用。主要分析了离心式水泵的工作原理和工作部件,提出了一系列操作和维护的有效措施。%In the process of mine construction and production ,centrifugal water pumps play an important role in drainage ,the correct use and maintenance of centrifugal water pumps are the decisive factor .This article mainly analyzed the working principle and working parts of centrifugal pumps ,then put forward a series of effective measures for the operation and maintenance of centrifugal pumps .

  4. 21 CFR 870.4370 - Roller-type cardiopulmonary bypass blood pump.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Roller-type cardiopulmonary bypass blood pump. 870... Roller-type cardiopulmonary bypass blood pump. (a) Identification. A roller-type cardiopulmonary bypass blood pump is a device that uses a revolving roller mechanism to pump the blood through...

  5. 21 CFR 870.4360 - Nonroller-type cardiopulmonary bypass blood pump.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonroller-type cardiopulmonary bypass blood pump... Nonroller-type cardiopulmonary bypass blood pump. (a) Identification. A nonroller-type cardiopulmonary bypass blood pump is a device that uses a method other than revolving rollers to pump the blood...

  6. Proton-Pump Inhibitors Therapy and Blood Pressure Control

    OpenAIRE

    Juan Francisco Sánchez Muñoz-Torrero; Pedro Joya-Vazquez; M Asunción Bacaicoa; Raul Velasco; Jose L. Chicón; Sara Trejo; M. Antonia Carrasco; N. Roberto Robles

    2014-01-01

    Objective: To evaluate  the potential impact of inhibitors of proton-pump in blood-pressure. .Methods: In a 24-hour-ambulatory-blood-pressure-monitoring (AMBP)-database we analyzed records of 462-hypertensive-patients according Proton-Pump Inhibitors (PPI). 150(33%)-patients were regularly users of PPI, and 312(67%) nonusers of PPI. Ambulatory-blood-pressure was measured non-invasively for 24--hours by the Spacelab-devices programmed-to-measure every 20-minutes during-daytime and every 60-min...

  7. Rotor-dynamic design aspects for a variable frequency drive based high speed cryogenic centrifugal pump in fusion devices

    International Nuclear Information System (INIS)

    Superconducting magnets of large size are inevitable for fusion devices due to high magnetic field requirements. Forced flow cooling of the superconducting magnets with high mass flowrate of the order ∼3 kg/s is required to keep superconducting magnets within its safe operational boundaries during various plasma scenarios. This important requirement can be efficiently fulfilled by employing high capacity and high efficiency cryogenic centrifugal pumps. The efficiency > 70% will ensure overall lower heat load to the cryoplant. Thermo-hydraulic design of cryogenic centrifugal pump revealed that to achieve the operational regime with high efficiency, the speed should be ∼ 10,000 revolutions per minute. In this regard, the rotor-dynamic design aspect is quite critical from the operational stability point of view. The rotor shaft design of the cryogenic pump is primarily an outcome of optimization between thermal heat-in leak at cryogenic temperature level from ambient, cryogenic fluid impedance and designed rotation speed of the impeller wheel. The paper describes the basic design related to critical speed of the rotor shaft, rotor whirl and system instability prediction to explore the ideal operational range of the pump from the system stability point of view. In the rotor-dynamic analysis, the paper also describes the Campbell plots to ensure that the pump is not disturbed by any of the critical speeds, especially while operating near the nominal and enhanced operating modes. (author)

  8. Method of evaluation of efficiency improvement potential for water supply systems with focus on variable speed centrifugal pumps

    Directory of Open Access Journals (Sweden)

    D. Pilscikovs

    2012-11-01

    Full Text Available The goal of this research is the derivation of the method for evaluation of efficiency improvement potential for public water supply systems with a focus on centrifugal network pumps. The efficiency of proportional pressure control usage has been analyzed for variable speed pumps. It has been done if proportional pressure control is used in comparison with constant pressure control mode. For this reason, energy calculation analyses have been realized for variable speed centrifugal pumps, and the theoretical tool of estimation of the efficiency improvement potential for public water supply systems has been derived. The conclusions are as follows: (1 it has been found that 1110 MWh of annually consumed electrical energy can be saved up, if the control mode of variable speed network pumps will be changed from constant pressure to proportional pressure control mode with the deviation of 20% from head value of duty point at zero flow; (2 about 13 MWh of annually consumed electrical energy can be saved up, if the proportional pressure control mode with the deviation of 15% will be changed to the deviation of 20%; (3 totally about 1123 MWh or 1.12 GWh (14% of the annually consumed electrical energy by variable speed network pumps can be saved up in small public water supply systems in Latvia.

  9. Evaluating the role of low-speed centrifugation towards transfecting human peripheral blood mononuclear cell culture

    Directory of Open Access Journals (Sweden)

    M Majumdar

    2014-01-01

    Full Text Available The conventional method of transfection of suspension cells by chemical has proven to be very difficult. We present a new transfection protocol, wherein, low-speed centrifugation of cell culture plates immediately after adding the lipid: DNA complex significantly enhances the transfection efficiency. Peripheral blood mononuclear cells (PBMCs were transfected with BLOCK-iT™ Fluorescent Oligo (scrambled siRNA and lipofectamine complex using conventional and low-speed centrifugation modified transfection protocols. The efficiency of transfection was determined using flowcytometer and cell viability was checked using MTT assay. Incorporation of low-speed centrifugation significantly enhances the transfection efficiency of BLOCK-iT™ in the suspension culture of PBMCs as compared to conventional transfection method (99.8% vs 28.3%; P < 0.0001, even at a low concentration of 40 picomoles without affecting the cell viability. Centrifugation enhanced transfection (CET technique is simple, time-saving and novel application without compromising the cell viability in the context of recently popular RNA interference in suspension cultures of PBMCs. This undemanding modification might be applicable to a wide variety of cell lines and solve crucial problem of researchers working with RNA interference in suspension cultures.

  10. Research on Three-Dimensional Unsteady Turbulent Flow in Multistage Centrifugal Pump and Performance Prediction Based on CFD

    Directory of Open Access Journals (Sweden)

    Zhi-jian Wang

    2013-01-01

    Full Text Available The three-dimensional flow physical model of any stage of the 20BZ4 multistage centrifugal pump is built which includes inlet region, impeller flow region, guide-vane flow region and exit region. The three-dimensional unsteady turbulent flow numerical model is created based on Navier-Stoke solver and standard k-ε turbulent equations. The method of multireference frame (MRF and SIMPLE algorithm are used to simulate the flow in multistage centrifugal pump based on FLUENT software. The distributions of relative velocity, absolute velocity, static pressure, and total pressure in guide vanes and impellers under design condition are analyzed. The simulation results show that the flow in impeller is mostly uniform, without eddy, backflow, and separation flow, and jet-wake phenomenon appears only along individual blades. There is secondary flow at blade end and exit of guide vane. Due to the different blade numbers of guide vane and impeller, the total pressure distribution is asymmetric. This paper also simulates the flow under different working conditions to predict the hydraulic performances of centrifugal pump and external characteristics including flow-lift, flow-shaft power, and flow-efficiency are attained. The simulation results are compared with the experimental results, and because of the mechanical losses and volume loss ignored, there is a little difference between them.

  11. "空心转子"血泵的技术发展及初步结果%Technical development and initial tests of a " hollow-rotor" blood pump

    Institute of Scientific and Technical Information of China (English)

    D.Baykut; S.Fabbri; M.Jeker; R.Pfluger; T.Ruppli; E.Schkommodau

    2010-01-01

    @@ Background: Ventricular assist devices are lifesaving for patients with end-stage heart failure who have no other options to survive until heart transplantation.The majority of new-generation devices are fully implantable blood pumps with axial or centrifugal flow directions.Current axial-flow blood pumps contain a conveying spiral for blood transport with a central rotating body and have very suitable dimensions for implantation.

  12. Shallow Discussion on the Chemical Centrifugal Pump Maintenance and Repair%浅谈化工用离心泵的维护及检修

    Institute of Scientific and Technical Information of China (English)

    张勇

    2011-01-01

    The various types of centrifugal pump maintenance were supplied.Arise through the centrifugal pump failure analysis in order to find the best way to repair.%提出离心泵维修的各种类型。通过对离心泵出现的各种故障分析从而找到维修的最佳方法。

  13. Acute hydrodynamic damage induced by SPLITT fractionation and centrifugation in red blood cells.

    Science.gov (United States)

    Urbina, Adriana; Godoy-Silva, Ruben; Hoyos, Mauricio; Camacho, Marcela

    2016-05-01

    Though blood bank processing traditionally employs centrifugation, new separation techniques may be appealing for large scale processes. Split-flow fractionation (SPLITT) is a family of techniques that separates in absence of labelling and uses very low flow rates and force fields, and is therefore expected to minimize cell damage. However, the hydrodynamic stress and possible consequent damaging effects of SPLITT fractionation have not been yet examined. The aim of this study was to investigate the hydrodynamic damage of SPLITT fractionation to human red blood cells, and to compare these effects with those induced by centrifugation. Peripheral whole blood samples were collected from healthy volunteers. Samples were diluted in a buffered saline solution, and were exposed to SPLITT fractionation (flow rates 1-10ml/min) or centrifugation (100-1500g) for 10min. Cell viability, shape, diameter, mean corpuscular hemoglobin, and membrane potential were measured. Under the operating conditions employed, both SPLITT and centrifugation maintained cell viability above 98%, but resulted in significant sublethal damage, including echinocyte formation, decreased cell diameter, decreased mean corpuscular hemoglobin, and membrane hyperpolarization which was inhibited by EGTA. Wall shear stress and maximum energy dissipation rate showed significant correlation with lethal and sublethal damage. Our data do not support the assumption that SPLITT fractionation induces very low shear stress and is innocuous to cell function. Some changes in SPLITT channel design are suggested to minimize cell damage. Measurement of membrane potential and cell diameter could provide a new, reliable and convenient basis for evaluation of hydrodynamic effects on different cell models, allowing identification of optimal operating conditions on different scales. PMID:27023157

  14. Evaluation of four blood pump geometries: the optical tracer technique.

    Science.gov (United States)

    Rose, M L; Mackay, T G; Martin, W; Wheatley, D J

    2000-01-01

    Artificial blood pump assistance of the failing human heart can allow it to recover. Analysis of blood pump fluid flow is a useful tool for design development and thrombosis minimization. The aim of this study was to investigate fluid flow, particularly ventricular clearance rate and stagnation areas, in four different blood pump geometries and to determine the best design. The blood pumps consisted of a polyurethane ventricle, and combinations of inlet/outlet pipe angles and compression plate shapes. A video camera recorded the motion of fluid labelled with an optical tracer (Methyl Blue histological dye). A novel processing method was developed to produce colour maps of tracer concentration, experimentally calibrated. An overall picture of fluid flow in each pump geometry was generated by considering clearance curves, tracer concentration maps and inflow jet animations. Overall and local mixing coefficients are calculated for each pump. The best geometry featured straight inlet/outlet pipes and a domed compression plate. This optical tracer technique has proven convenient, economical, sensitive to low concentrations of tracer and provides instantaneous pictures of tracer distribution in a ventricle. PMID:10997058

  15. Analysis and Improvement of Centrifugal Pump Com-mon Fault%关于离心泵常见故障的解析和改进

    Institute of Scientific and Technical Information of China (English)

    吴正军

    2014-01-01

    In recent years , with the progress and development of petroleum industry , centrifugal pumps as common oil equipment , often appear some fault in the production process and affect work efficiency . Therefore , strengthening centrifugal pumps common breakdown maintenance and doing a good job management are very important . This article mainly analyzes common faults of centrifugal pump in using process , expounds the importance of strengthening centrifugal pump maintenance and repair , and put forward some maintenance techniques and methods in accordance with present research and analysis on the common problem of centrifugal pump , hoping that through such analysis and research , it can realize the strategic target for optimization of centrifugal pump efficiency .%本文主要分析了离心泵在使用过程中常见的故障,阐述了加强离心泵维护和修理的重要性,提出一些离心泵检维修技术和方法。希望通过本文的分析、研究,能实现优化离心泵运行效率的战略目标。

  16. [Pre-analytical stability before centrifugation of 7 biochemical analytes in whole blood].

    Science.gov (United States)

    Perrier-Cornet, Andreas; Moineau, Marie-Pierre; Narbonne, Valérie; Plee-Gautier, Emmanuelle; Le Saos, Fabienne; Carre, Jean-Luc

    2015-01-01

    The pre-analytical stability of 7 biochemical parameters (parathyroid hormone -PTH-, vitamins A, C E and D, 1,25-dihydroxyvitamin D and insulin) at +4 °C, was studied on whole blood samples before centrifugation. The impact of freezing at -20°C was also analyzed/performed for PTH and vitamin D. The differences in the results of assays for whole blood samples, being kept for different times between sampling time and analysis, from 9 healthy adults, were compaired by using a Student t test. The 7 analytes investigated remained stable up to 4 hours at +4°C in whole blood. This study showed that it is possible to accept uncentrifuged whole blood specimens kept at +4°C before analysis. PTH is affected by freezing whereas vitamin D is not. PMID:26411912

  17. Application of a magnetic fluid seal to rotary blood pumps

    International Nuclear Information System (INIS)

    A magnetic fluid seal enables mechanical contact-free rotation of a shaft without frictional heat and material wear and hence has excellent durability. However, the durability of a magnetic fluid seal decreases in liquid. The life of a seal applied to a rotary blood pump is not known. We have developed a magnetic fluid seal that has a shield mechanism minimizing the influence of the rotary pump on the magnetic fluid. The developed magnetic fluid seal worked for over 286 days in a continuous flow condition, for 24 days (on-going) in a pulsatile flow condition and for 24 h (electively terminated) in blood flow. The magnetic fluid seal is promising as a shaft seal for rotary blood pumps

  18. Evaluating the role of low-speed centrifugation towards transfecting human peripheral blood mononuclear cell culture.

    Science.gov (United States)

    Majumdar, M; Ratho, R; Chawla, Y; Singh, M P

    2014-01-01

    The conventional method of transfection of suspension cells by chemical has proven to be very difficult. We present a new transfection protocol, wherein, low-speed centrifugation of cell culture plates immediately after adding the lipid: DNA complex significantly enhances the transfection efficiency. Peripheral blood mononuclear cells (PBMCs) were transfected with BLOCK-iT™ Fluorescent Oligo (scrambled siRNA) and lipofectamine complex using conventional and low-speed centrifugation modified transfection protocols. The efficiency of transfection was determined using flowcytometer and cell viability was checked using MTT assay. Incorporation of low-speed centrifugation significantly enhances the transfection efficiency of BLOCK-iT™ in the suspension culture of PBMCs as compared to conventional transfection method (99.8% vs 28.3%; P saving and novel application without compromising the cell viability in the context of recently popular RNA interference in suspension cultures of PBMCs. This undemanding modification might be applicable to a wide variety of cell lines and solve crucial problem of researchers working with RNA interference in suspension cultures. PMID:24713904

  19. Application of Vane Cutting of Centrifugal Pump to Save Energy%离心泵叶轮切削节能改造应用

    Institute of Scientific and Technical Information of China (English)

    杨程; 杨东旭; 王长友

    2014-01-01

    Due to difference between the design of centrifugal pump and production op-eration of the thermal power plant, operation and equipment modification of the water pump led to deviation of the centrifugal pump performance curve from high efficiency range, result-ing in big waste of electricity. Thus the performance parameters of the centrifugal pump needed to be corrected with minimum replacement of parts and minimum cost. A fast and reliable energy saving method for the centrifugal pump was obtained by experiment of turning of centrifugal pump vanes to modify operation condition.%由于离心泵设计与热电厂生产运行中的差距,在水泵运行和设备改造带来了离心泵性能曲线与高效区的偏离,带来了电能的极大浪费,这就需要通过更改最少的部件和最低的成本,使离心泵性能参数得到校正。通过车削离心泵叶轮切割的试验及方法,改变运行工况,得出快捷、可靠的离心泵节能方法。

  20. Parameter estimation and actuator characteristics of hybrid magnetic bearings for axial flow blood pump applications.

    Science.gov (United States)

    Lim, Tau Meng; Cheng, Shanbao; Chua, Leok Poh

    2009-07-01

    Axial flow blood pumps are generally smaller as compared to centrifugal pumps. This is very beneficial because they can provide better anatomical fit in the chest cavity, as well as lower the risk of infection. This article discusses the design, levitated responses, and parameter estimation of the dynamic characteristics of a compact hybrid magnetic bearing (HMB) system for axial flow blood pump applications. The rotor/impeller of the pump is driven by a three-phase permanent magnet brushless and sensorless motor. It is levitated by two HMBs at both ends in five degree of freedom with proportional-integral-derivative controllers, among which four radial directions are actively controlled and one axial direction is passively controlled. The frequency domain parameter estimation technique with statistical analysis is adopted to validate the stiffness and damping coefficients of the HMB system. A specially designed test rig facilitated the estimation of the bearing's coefficients in air-in both the radial and axial directions. Experimental estimation showed that the dynamic characteristics of the HMB system are dominated by the frequency-dependent stiffness coefficients. By injecting a multifrequency excitation force signal onto the rotor through the HMBs, it is noticed in the experimental results the maximum displacement linear operating range is 20% of the static eccentricity with respect to the rotor and stator gap clearance. The actuator gain was also successfully calibrated and may potentially extend the parameter estimation technique developed in the study of identification and monitoring of the pump's dynamic properties under normal operating conditions with fluid. PMID:19566728

  1. Centrifugation:an important pre-analytic procedure that influences plasma microRNA quantification during blood processing

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hui Zheng; Cui Cui; Xin-Xi Zhou; Yi-Xin Zeng; Wei-Hua Jia

    2013-01-01

    Circulating microRNAs are robustly present in plasma or serum and have become a research focus as biomarkers for tumor diagnosis and prognosis. Centrifugation is a necessary procedure for obtaining high-quality blood supernatant. Herein, we investigated one-step and two-step centrifugations, two centrifugal methods routinely used in microRNA study, to explore their effects on plasma microRNA quantification. The microRNAs obtained from one-step and two-step centrifugations were quantified by microarray and TaqMan-based real-time quantitative polymerase chain reaction (Q-PCR). Dynamic light scattering was performed to explore the difference underlying the two centrifugal methods. The results from the microarray containing 1,347 microRNAs showed that the signal detection rate was greatly decreased in the plasma sample prepared by two-step centrifugation. More importantly, the microRNAs missing in this plasma sample could be recovered and detected in the precipitate generated from the second centrifugation. Consistent with the results from microarray, a marked decrease of three representative microRNAs in two-step centrifugal plasma was validated by Q-PCR. According to the size distribution of all nanoparticles in plasma, there were fewer nanoparticles with size >1,000 nm in two-step centrifugal plasma. Our experiments directly demonstrated that different centrifugation methods produced distinct quantities of plasma microRNAs. Thus, exosomes or protein complexes containing microRNAs may be involved in large nanoparticle formation and may be precipitated after two-step centrifugation. Our results remind us that sample processing methods should be first considered in conducting research.

  2. 用引射技术提高离心泵的汽蚀性能%Improving suction performance of Centrifugal Pumps by Using Jetting Device

    Institute of Scientific and Technical Information of China (English)

    崔宝玲; 朱祖超; 张剑慈; 吴昱; 陈鹰

    2004-01-01

    Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%.

  3. Blood Pump Development Using Rocket Engine Flow Simulation Technology

    Science.gov (United States)

    Kwak, Dochan; Kiris, Cetin

    2001-01-01

    This paper reports the progress made towards developing complete blood flow simulation capability in humans, especially in the presence of artificial devices such as valves and ventricular assist devices. Devices modeling poses unique challenges different from computing the blood flow in natural hearts and arteries. There are many elements needed to quantify the flow in these devices such as flow solvers, geometry modeling including flexible walls, moving boundary procedures and physiological characterization of blood. As a first step, computational technology developed for aerospace applications was extended to the analysis and development of a ventricular assist device (VAD), i.e., a blood pump. The blood flow in a VAD is practically incompressible and Newtonian, and thus an incompressible Navier-Stokes solution procedure can be applied. A primitive variable formulation is used in conjunction with the overset grid approach to handle complex moving geometry. The primary purpose of developing the incompressible flow analysis capability was to quantify the flow in advanced turbopump for space propulsion system. The same procedure has been extended to the development of NASA-DeBakey VAD that is based on an axial blood pump. Due to massive computing requirements, high-end computing is necessary for simulating three-dimensional flow in these pumps. Computational, experimental, and clinical results are presented.

  4. The Review on Energy Saving Technology Development and Prospect of Centrifugal Pump%离心泵的节能技术发展及前景分析

    Institute of Scientific and Technical Information of China (English)

    凌素琴; 陈勇; 刘莉

    2014-01-01

    It analyzes the current main problems of domestic energy saving technology in centrifugal pump manu -facture , presents the detail technical way for centrifugal pump energy saving from the pump design , manufactur-ing, the system cooperation with connection accessories , the integration of mechanical and electrical instrument development and application .Finally it describes the prospect of energy saving technology for centrifugal pump .%分析了目前国内离心泵在节能方面存在的主要问题,分别从单泵的设计和制造、系统的连接附件配合、机电仪一体化发展以及使用方面有针对性地提出了离心泵节能的技术途径,并对离心泵节能技术客观地进行了前景分析。

  5. Effect of Blade Outlet Angle on Unsteady Hydrodynamic Force of Closed-Type Centrifugal Pump with Single Blade

    Directory of Open Access Journals (Sweden)

    Yasuyuki Nishi

    2014-01-01

    Full Text Available Geometrically, the single-blade centrifugal impeller, commonly used today as a sewage pump, is not axially symmetric. For this reason, the static pressure around the impeller fluctuates greatly when the impeller is rotating, and not only the radial thrust but also the axial thrust shows large fluctuations. Therefore, it is extremely important for the improvement of pump reliability to quantitatively grasp these fluctuating hydrodynamic forces. In this study, we investigated the unsteady hydrodynamic forces in a closed-type centrifugal pump with a single blade for different blade outlet angles using a numerical analysis that takes into account both experiment and the leakage flow. The results clearly showed the effect of the blade outlet angle on that act on the impeller. The root-mean-square value of the fluctuating component of the total radial thrust was roughly the same for whichever impeller at low flow rate, but at high flow rates, the value increased for impellers with larger blade outlet angles. Moreover, when the leakage flow rate increased with increasing static pressure around the impeller, such that the rear and front shroud parts were subject to high pressure, the absolute value of the axial thrust on both these parts increased.

  6. Numerical Research on Hydraulically Generated Vibration and Noise of a Centrifugal Pump Volute with Impeller Outlet Width Variation

    Directory of Open Access Journals (Sweden)

    Houlin Liu

    2014-01-01

    Full Text Available The impeller outlet width of centrifugal pumps is of significant importance for numbers of effects. In the paper, these effects including the performance, pressure pulsations, hydraulically generated vibration, and noise level are investigated. For the purpose, two approaches were used to predict the vibration and sound radiation of the volute under fluid excitation force. One approach is the combined CFD/FEM analysis for structure vibration, and then the structure response obtained from the FEM analysis is treated as the boundary condition for BEM analysis for sound radiation. The other is the combined CFD/FEM/BEM coupling method. Before the numerical methods were used, the simulation results were validated by the vibration acceleration of the monitoring points on the volute. The vibration and noise were analyzed and compared at three flow conditions. The analysis of the results shows that the influences of the sound pressure of centrifugal pumps on the structure appear insignificant. The relative outlet width b2* at nq(SI = 26.7 in this paper should be less than 0.06, based on an overall consideration of the pump characteristics, pressure pulsations, vibration and noise level.

  7. On the Effect of Cavitation on the Radial Forces and Hydrodynamic Stiffness of a Centrifugal Pump

    OpenAIRE

    Franz, R. J.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1986-01-01

    The asymmetric flow within a volute exerts a radial force on a centrifugal impeller. The present paper presents experimental measurements of the radial forces on the impeller in the presence of cavitation.

  8. A test program to measure fluid mechanical whirl-excitation forces in centrifugal pumps

    Science.gov (United States)

    Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1980-01-01

    The details of a test program for the measurement of the unsteady forces on centrifugal impellers are discussed. Various hydrodynamic flows are identified as possible contributors to these destabilizing forces.

  9. Mechanical axial flow blood pump to support cavopulmonary circulation.

    Science.gov (United States)

    Throckmorton, A L; Kapadia, J; Madduri, D

    2008-11-01

    We are developing a collapsible, percutaneously inserted, axial flow blood pump to support the cavopulmonary circulation in infants with a failing single ventricle physiology. An initial design of the impeller for this axial flow blood pump was performed using computational fluid dynamics analysis, including pressure-flow characteristics, scalar stress estimations, blood damage indices, and fluid force predictions. A plastic prototype was constructed for hydraulic performance testing, and these experimental results were compared with the numerical predictions. The numerical predictions and experimental findings of the pump performance demonstrated a pressure generation of 2-16 mm Hg for 50-750 ml/min over 5,500-7,500 RPM with deviation found at lower rotational speeds. The axial fluid forces remained below 0.1 N, and the radial fluid forces were determined to be virtually zero due to the centered impeller case. The scalar stress levels remained below 250 Pa for all operating conditions. Blood damage analysis yielded a mean residence time of the released particles, which was found to be less than 0.4 seconds for both flow rates that were examined, and a maximum residence time was determined to be less than 0.8 seconds. We are in the process of designing a cage with hydrodynamically shaped filament blades to act as a diffuser and optimizing the impeller blade shape to reduce the flow vorticity at the pump outlet. This blood pump will improve the clinical treatment of patients with failing Fontan physiology and provide a unique catheter-based therapeutic approach as a bridge to recovery or transplantation. PMID:19089799

  10. 离心输油泵性能换算的简捷计算方法%Short Way to Converse Performance of Centrifugal Pumps

    Institute of Scientific and Technical Information of China (English)

    孙伟; 汪玉春

    2009-01-01

    以离心泵特性曲线换算图为原始数据,建立了离心输油泵性能换算数学模型.采用Levenberg-Marquardt法优化了数学模型,将泵效率换算系数准确描述为与流量、扬程、原油粘度的非线性函数关系.在建模基础上,利用计算机程序设计建立了离心输油泵性能自动换算系统,该系统能够简捷、准确地优化泵机组设计或运行方案,实现泵性能的自动化换算.%Taking the characteristic curve conversion diagram of centrifugal pump as an original data,a mathematical model for characteristic conversion of centrifugal pumps is set up.Levenberg-Marquardt method is used to optimize the model and the conversion coefficient of pump efficiency is described as a non-linear function with flowrate,pump discharge head and oil viscosity.On the basis of model,performance automatic conversion system for centrifugal pump is established by program design of computer system.A calculation example shows that this system can shortly and accurately optimize the design or operation scenario for pump sets and realize performance automatic conversion for centrifugal pumps.

  11. 浅谈离心式水泵启动时真空的重要性%Discussion on Significance of Vacuum while Starting up Centrifugal Water Pump

    Institute of Scientific and Technical Information of China (English)

    宋红英

    2011-01-01

    The paper presents the structure and working principles of centrifugal water pump and analyzes the hazards caused by the air existing in pump,which shows that vacuum is essential to the pump drainage.%阐述了离心式水泵的结构和工作原理,说明真空是水泵排水的必要条件。分析泵内存有空气引起的危害。

  12. The application of acoustic emission for detecting incipient cavitation and the best efficiency point of a 60 kW centrifugal pump: case study

    OpenAIRE

    Alfayez, L; Mba, David; Dyson, G.

    2005-01-01

    Pumps play a significant role in industrial plants and need continuous monitoring to minimise loss of production. To date, there is limited published information on the application of acoustic emission (AE) to incipient pump cavitation. This paper presents a case study where AE has been applied for detecting incipient cavitation and determining the best efficiency point (BEP) of a 60 kW centrifugal pump. Results presented are based on net positive suction head (NPSH) and per...

  13. 浅析化工装置中离心泵汽蚀的有效解决方法%Briefly Analyzing Effective Solution Method for Centrifugal Pump Cavitation in Chemical Production

    Institute of Scientific and Technical Information of China (English)

    陈鹏

    2011-01-01

    简述了离心泵的工作原理和离心泵汽蚀的概念;分析了离心泵汽蚀产生的原因;提出了避免离心泵汽蚀的方法和措施。%Author has briefly described the working principle of centrifugal pump and concept of cavitation of centrifugal pump;has analyzed the caused reason of cavitation of centrifugal pump;has presented the methods and measures to avoid the cavitation of centrifugal pump.

  14. Designing and modeling a centrifugal microfluidic device to separate target blood cells

    International Nuclear Information System (INIS)

    The objective of this study is to design a novel and efficient portable lab-on-a-CD (LOCD) microfluidic device for separation of specific cells (target cells) using magnetic beads. In this study the results are shown for neutrophils as target cells. However, other kinds of target cells can be separated in a similar approach. The designed microfluidics can be utilized as a point of care system for neutrophil detection. This microfluidic system employs centrifugal and magnetic forces for separation. After model validation by the experimental data in the literature (that may be used as a design tool for developing centrifugo-magnetophoretic devices), two models are presented for separation of target cells using magnetic beads. The first model consists of one container in the inlet section and two containers in the outlets. Initially, the inlet container is filled with diluted blood sample which is a mixture of red blood cells (RBCs) plus neutrophils which are attached to Magnetic beads. It is shown that by using centrifugal and magnetic forces, this model can separate all neutrophils with recovery factor of ∼100%. In the second model, due to excess of magnetic beads in usual experimental analysis (to ensure that all target cells are attached to them) the geometry is improved by adding a third outlet for these free magnetic beads. It is shown that at angular velocity of 45 rad s−1, recovery factor of 100% is achievable for RBCs, free magnetic beads and neutrophils as target cells. (paper)

  15. Designing and modeling a centrifugal microfluidic device to separate target blood cells

    Science.gov (United States)

    Shamloo, Amir; Selahi, AmirAli; Madadelahi, Masoud

    2016-03-01

    The objective of this study is to design a novel and efficient portable lab-on-a-CD (LOCD) microfluidic device for separation of specific cells (target cells) using magnetic beads. In this study the results are shown for neutrophils as target cells. However, other kinds of target cells can be separated in a similar approach. The designed microfluidics can be utilized as a point of care system for neutrophil detection. This microfluidic system employs centrifugal and magnetic forces for separation. After model validation by the experimental data in the literature (that may be used as a design tool for developing centrifugo-magnetophoretic devices), two models are presented for separation of target cells using magnetic beads. The first model consists of one container in the inlet section and two containers in the outlets. Initially, the inlet container is filled with diluted blood sample which is a mixture of red blood cells (RBCs) plus neutrophils which are attached to Magnetic beads. It is shown that by using centrifugal and magnetic forces, this model can separate all neutrophils with recovery factor of ~100%. In the second model, due to excess of magnetic beads in usual experimental analysis (to ensure that all target cells are attached to them) the geometry is improved by adding a third outlet for these free magnetic beads. It is shown that at angular velocity of 45 rad s-1, recovery factor of 100% is achievable for RBCs, free magnetic beads and neutrophils as target cells.

  16. The Operational Features of Pumping Stations Equiped with Parallel-Connected Centrifugal Pumps for Land-Reclamation

    Directory of Open Access Journals (Sweden)

    Khalid S. Al-Rababa

    2005-01-01

    Full Text Available The required water supply of a pump could be provided by means of different combinations of pressure piping and pumping units at different operational costs. The basic indices describing the operational modes for the individual and group pumping units, including the values of the efficiency, are computed. The adequacy of the calculational results that based on the developed mathematical models is confirmed by the full-scale experimental researches. Based on the presented principles of the load distribution between parallel working pumping units, 5 % of consumed electric power may be saved.

  17. Classification of Unsteady Flow Patterns in a Rotodynamic Blood Pump: Introduction of Non-Dimensional Regime Map.

    Science.gov (United States)

    Shu, Fangjun; Vandenberghe, Stijn; Brackett, Jaclyn; Antaki, James F

    2015-09-01

    Rotodynamic blood pumps (also known as rotary or continuous flow blood pumps) are commonly evaluated in vitro under steady flow conditions. However, when these devices are used clinically as ventricular assist devices (VADs), the flow is pulsatile due to the contribution of the native heart. This study investigated the influence of this unsteady flow upon the internal hemodynamics of a centrifugal blood pump. The flow field within the median axial plane of the flow path was visualized with particle image velocimetry (PIV) using a transparent replica of the Levacor VAD. The replica was inserted in a dynamic cardiovascular simulator that synchronized the image acquisition to the cardiac cycle. As compared to steady flow, pulsatile conditions produced periodic, transient recirculation regions within the impeller and separation in the outlet diffuser. Dimensional analysis revealed that the flow characteristics could be uniquely described by the non-dimensional flow coefficient (Φ) and its time derivative ([Formula: see text]), thereby eliminating impeller speed from the experimental matrix. Four regimes within the Φ-[Formula: see text] plane were found to classify the flow patterns, well-attached or disturbed. These results and methods can be generalized to provide insights for both design and operation of rotodynamic blood pumps for safety and efficacy. PMID:26577357

  18. Centrifugal Pumps for Swimming Pools. National Sanitation Foundation Standard Number 17.

    Science.gov (United States)

    National Sanitation Foundation, Ann Arbor, MI. Committee for Swimming Pool Equipment Standards.

    The pumps discussed herein are intended to be used for recirculating water in swimming pools, both public and private. Included are the basic components which may be a part of a pump such as the housing, strainer, impeller, valves, and such other parts as are attached or a part of the pump as supplied by the manufacturer. This standard is intended…

  19. Component Analysis of Unsteady Hydrodynamic Force of Closed-Type Centrifugal Pump with Single Blades of Different Blade Outlet Angles

    Directory of Open Access Journals (Sweden)

    Yasuyuki Nishi

    2015-01-01

    Full Text Available Single-blade centrifugal impellers for sewage systems undergo both unsteady radial and axial thrusts. Therefore, it is extremely important for the improvement of pump reliability to quantitatively grasp these fluctuating hydrodynamic forces and determine the generation mechanism behind them. In this study, we conducted component analyses of radial and axial thrusts of closed, single-blade centrifugal pumps with different blade outlet angles by numerical analysis while considering leakage flow. The results revealed the effect of the blade outlet angle on the components of radial and axial thrusts. For increased flow rates, the time-averaged values of the pressure component were similar for all impellers, although its fluctuating components were higher for impellers with larger blade outlet angles. Moreover, the fluctuating inertia component of the impeller with a blade outlet angle of 8° decreased as the flow rate increased, whereas those with 16° and 24° angles increased. Therefore, the radial thrust on the hydraulic part was significantly higher for impellers with high blade outlet angles.

  20. Study on Internal Flow and External Performance of a Semi-open Impeller Centrifugal Pump with Different Tip Clearances

    Science.gov (United States)

    Jia, Xiao-Qi; Cui, Bao-Ling; Zhang, Yu-Liang; Zhu, Zu-Chao

    2015-04-01

    To study the influence of tip clearance on internal flow characteristics and external performance of a prototype centrifugal pump with a semi-open impeller, the unsteady numerical simulation and performance experiments are carried out in this paper. The evolution process of leakage vortex with time t, the flow characteristics and the magnitude of leakage rate in tip clearance are obtained in details. The results indicate that the H-Q curve hump of centrifugal pump shows a weakened trend with the increasing of tip clearance Δc. Meanwhile, the leakage rate ΔQ and the ratio of leakage rate to discharge flow rate (ψ) gradually increase. At the same tip clearance, the leakage rate ΔQ increases, while the ratio of leakage rate to discharge flow rate (ψ) decreases with the increasing of discharge flow rate Q. It is found that higher volumetric loss account for a higher percentage of the total loss at small flow rate condition. There easily exist strong leakage vortexes in the impeller inlet, impeller passage and impeller outlet. The pressure difference between suction side and pressure side makes the fluid pass through the tip clearance layer to form a lower pressure region and leakage vortex.

  1. 高速离心泵的设计与试验研究%DESIGN AND STUDY ON HIGH SPEED CENTRIFUGAL PUMP

    Institute of Scientific and Technical Information of China (English)

    舒安庆; 胡家顺

    2001-01-01

    A design method of high speed centrifugal pump was given to satisfy the requirements of small centrifugal pump volume and light equipment weight.The testing result proved that the high speed centrifugal pump designed by that method could conform with design requirements of high efficiency and stable performace.And gave a reference to design for the same trade.%为满足离心泵体积小、重量轻的要求,提出了一种高速离心泵的设计方法,测试结果表明,采用该设计方法设计的高速离心泵效率高、性能稳定,能满足设计要求。

  2. Expert system for the diagnosis of the condition and performance of centrifugal pumps

    Energy Technology Data Exchange (ETDEWEB)

    Jantunen, E.; Vaehae-Pietilae, K.; Pesonen, K. [Technical Research Centre of Finland, Manufacturing Technology, Espoo (Finland)

    1997-12-31

    A brief description of the results of a study concerning the maintenance and downtime costs in Finnish pumping is given. The leakage of seals was found to be the fault that causes the highest downtime and maintenance costs. A small laboratory arrangement has been used to test the effectiveness of various condition monitoring methods. This information has been used in the development of a diagnostic expert system called CEPDIA, which can be used for diagnosing the condition of a pump and its components. The diagnosis is based on measuring results obtained from sensors and on information about maintenance actions carried out with the pump and its components. The principles of the CEPDIA expert system are described. A database is included in the system for handling and saving the measurement results, technical information on the pumps and maintenance actions carried out with the pumps. The diagnosis can also be based on vibration signature analysis, which is quite effective in determining which fault is the actual cause of malfunction of the pump or its components. CEPDIA can also be used to calculate of the efficiency of the electrical motor and the pump. CEPDIA has been tested in the diagnosis of 63 pumps. The average efficiency in pumping was less than 40 %, and more than 10 % of the pumps were pumping with less than 10 % efficiency. (orig.) 11 refs.

  3. CALCULATION OF SPLITTING VANES AND INNER FLOW ANALYSIS FOR CENTRIFUGAL PUMP IMPELLER

    Institute of Scientific and Technical Information of China (English)

    Pan Zhongyong; Yuan Shouqi; Li Hong; Cao Weidong

    2004-01-01

    The calculation method for vane numbers is obtained on the intention that it should have no back flow area in the flow passage of centrifugal passage.Then a criterion that the design of splitting vanes of centrifugal compound impeller should ensure that the back flow area ratio be the minimum is proposed.On the basis of the criterion, the slippery theory is used as one of CFD methods to analyze the inner flow field of the impeller of various kinds of splitting vanes design, therefore, the optimized design of splitting vanes is obtained and which agrees with that of some testing results.

  4. CFD Application in Implantable Rotary Blood Pump Design and Validation

    Institute of Scientific and Technical Information of China (English)

    YI Qian

    2004-01-01

    Implantable rotary blood pump (IRBP) has been promoted to the stage of clinical trial. This paper introduces a unique IRBP without a shaft. Instead of using thrombogenic pivots or power-drawing magnetic suspension, impeller is supported hydrodynamically when rotating, by lubrication flows in the thin spaces between itself and the pump body. To this end, the flow is very difficult to be measured using usual laboratory equipments. Therefore, computational fluid dynamics (CFD) has been applied as an important tool in the IRBP design and its validation procedure. Several CFD results such as pump performance improvement, unsteady hydraulic dynamic analysis, biocapability prediction, validation and verification (V&V), and flow visualization have been performed.

  5. CFD Application in Implantable Rotary Blood Pump Design and Validation

    Institute of Scientific and Technical Information of China (English)

    YIQian

    2004-01-01

    Implantable rotary blood pump (IRBP) has been promoted to the stage of clinical trial. This paper introduces a unique IRBP without a.shaft. Instead of using thrombogenic pivots or power-drawing magnetic suspension, impeller is supported hydrodynamically when rotating, by lubrication flows in the thin spaces between itself and the pump body. To this end, the flow is very difficult to be measured using usual laboratory equipments. Therefore, computational fluid dynamics (CFD) has been applied as an important tool in the IRBP design and its validation procedure. Several CFD results such as pump performance improvement, unsteady hydraulic dynamic analysis, biocapability prediction, validation and verification (V&V), and flow visualization have been performed.

  6. 离心泵机组中惯性飞轮装置的设计%Design of Inertia Flywheel in Centrifugal Pump System

    Institute of Scientific and Technical Information of China (English)

    汪永海

    2015-01-01

    对于离心泵作为冷却系统中的供液泵,在突然断电导致原动机失去动力的情况下,需要离心泵可以延时运转一段时间,并继续保持有一定的冷却液体输出,而常规的离心泵由于叶轮惯性相对较小,一旦原动机失去动力,离心泵会在液体的阻力作用下迅速停止;通过在离心泵机组中增加惯性飞轮作为储能装置,在原动机断电时,储能装置为离心泵提供动力,以实现延时运转并保持一定的液体输出,确保被冷却设备在突然断电时可以得到延时冷却,从而保护设备,并增加整个系统的处理时间。%For a centrifugal pump used in cooling system ,it needs the centrifugal pump keep running in the case of power outage,and continue pumping the liquid,but the ordinary centrifugal pump will stop very fast when power outage happened because of the small inertia of pump impeller. In order to keep the pump running after the power outage we add the inertia flywheel to the pump system. Inertia flywheel as an energy storage device can supply energy to the centrifugal pump when power outage happened, so that can drive the pump impeller running and pumping the liquid to protect the machine.

  7. Large-scale clinical comparison of the lysis-centrifugation and radiometric systems for blood culture

    International Nuclear Information System (INIS)

    The Isolator 10 lysis-centrifugation blood culture system (E. I. du Pont de Nemours and Co., Inc., Wilmington, Del.) was compared with the BACTEC radiometric method (Johnston Laboratories, Inc., Towson, Md.) with 6B and 7D broth media for the recovery of bacteria and yeasts. From 11,000 blood cultures, 1,174 clinically significant organisms were isolated. The Isolator system recovered significantly more total organisms, members of the family Enterobacteriaceae, Staphylococcus spp., and yeasts. The BACTEC system recovered significantly more Pseudomonas spp., Streptococcus spp., and anaerobes. Of the Isolator colony counts, 87% measured less than 11 CFU/ml of blood. Organisms, on an average, were detected the same day from each of the two culture systems. Only 13 of the 975 BACTEC isolates (0.01%) were recovered by subculture of growth-index-negative bottles, and 12 of the 13 were detected in another broth blood culture taken within 24 h. Contaminants were recovered from 4.8% of the Isolator 10 and 2.3% of the BACTEC cultures

  8. Blood Pump Development Using Rocket Engine Flow Simulation Technology

    Science.gov (United States)

    Kiris, Cetin C.; Kwak, Dochan

    2002-01-01

    This viewgraph presentation provides information on the transfer of rocket engine flow simulation technology to work involving the development of blood pumps. Details are offered regarding the design and requirements of mechanical heart assist devices, or VADs (ventricular assist device). There are various computational fluid dynamics issues involved in the visualization of flow in such devices, and these are highlighted and compared to those of rocket turbopumps.

  9. Development of a mercury electromagnetic centrifugal pump for the SNAP-8 refractory boiler development program

    Science.gov (United States)

    Fuller, R. A.; Schnacke, A. W.

    1974-01-01

    An electromagnetic pump, in which pressure is developed in mercury because of the interaction of the magnetic field and current which flows as a result of the voltage induced in the mercury contained in the pump duct, was developed for the SNAP-8 refractory boiler test facility. Pump performance results are presented for ten duct configurations and two stator sizes. These test results were used to design and fabricate a pump which met the SNAP-8 criteria of 530 psi developed pressure at 12,500 lb/hr. The pump operated continuously for over 13,000 hours without failure or performance degradation. Included in this report are descriptions of the experimental equipment, measurement techniques, all experimental data, and an analysis of the electrical losses in the pump.

  10. Numerical prediction of 3-D periodic flow unsteadiness in a centrifugal pump under part-load condition

    Institute of Scientific and Technical Information of China (English)

    裴吉; 袁寿其; 李晓俊; 袁建平

    2014-01-01

    Numerical simulation and 3-D periodic flow unsteadiness analysis for a centrifugal pump with volute are carried out in whole flow passage, including the impeller with twisted blades, the volute and the side chamber channels under a part-load condition. The pressure fluctuation intensity coefficient (PFIC) based on the standard deviation method, the time-averaged velocity unsteadi-ness intensity coefficient (VUIC) and the time-averaged turbulence intensity coefficient (TIC) are defined by averaging the results at each grid node for an entire impeller revolution period. Therefore, the strength distributions of the periodic flow unsteadiness based on the unsteady Reynolds-averaged Navier-Stokes (URANS) equations can be analyzed directly and in detail. It is shown that under the des.0.6Q condition, the pressure fluctuation intensity is larger near the blade pressure side than near the suction side, and a high fluctuation intensity can be observed at the beginning section of the spiral of the volute. The flow velocity unsteadiness intensity is larger near the blade suction side than near the pressure side. A strong turbulence intensity can be found near the blade suction side, the impeller shroud side as well as in the side chamber. The leakage flow has a significant effect on the inflow of the impeller, and can increase both the flow velocity unsteadiness intensity and the turbulence intensity near the wall. The accumulative flow unstea-diness results of an impeller revolution can be an important aspect to be considered in the centrifugal pump optimum design for ob-taining a more stable inner flow of the pump and reducing the flow-induced vibration and noise in certain components.

  11. Experimental characterization and modelling of a cavitating centrifugal pump operating in fast start-up conditions

    OpenAIRE

    Duplaa, Sébastien; COUTIER-DELGOSHA, Olivier; DAZIN, Antoine; BOIS, Gérard; CAIGNAERT, Guy

    2010-01-01

    International audience The start-up of rocket engine turbopumps is generally performed only in a few seconds. It implies that these pumps reach their nominal operating conditions after only a few rotations. During these first rotations of the blades, the flow evolution in the pump is governed by transient phenomena, based mainly on the flow rate and rotation speed evolution. These phenomena progressively become negligible when the steady behavior is reached. The pump transient behaviour in...

  12. The optimisation and analysis of a centrifugal slurry pump impeller with 2 blades

    OpenAIRE

    Mehmet Salih Cellek; Tahsin Engin

    2013-01-01

    With FLUENT, which is Computational Fluid Dynamics (CFD) software, it becomes possible to define the performance of complicated flow in turbo machines like pumps and blowers. It is not only reduced costs but also saves time. This study is aimed to optimize a commercial slurry pump impeller. Therefore, four different types of impellers were designed with using various blade angles, blade length and splitter blade on the impeller, which is the most crucial component of the pump. As a result of ...

  13. 85,000-GPM, single-stage, single-suction LMFBR intermediate centrifugal pump

    International Nuclear Information System (INIS)

    The mechanical and hydraulic design features of the 85,000-gpm, single-stage, single-suction pump test article, which is designed to circulate liquid-sodium coolant in the intermediate heat-transport system of a Large-Scale Liquid Metal Fast Breeder Reactor (LS-LMFBR), are described. The design and analytical considerations used to satisfy the pump performance and operability requirements are presented. The validation of pump hydraulic performance using a hydraulic scale-model pump is discussed, as is the featute test for the mechanical-shaft seal system

  14. The optimisation and analysis of a centrifugal slurry pump impeller with 2 blades

    Directory of Open Access Journals (Sweden)

    Mehmet Salih Cellek

    2013-08-01

    Full Text Available With FLUENT, which is Computational Fluid Dynamics (CFD software, it becomes possible to define the performance of complicated flow in turbo machines like pumps and blowers. It is not only reduced costs but also saves time. This study is aimed to optimize a commercial slurry pump impeller. Therefore, four different types of impellers were designed with using various blade angles, blade length and splitter blade on the impeller, which is the most crucial component of the pump. As a result of analysis it was seen that every impeller affected on the pump performance at different flow rate.

  15. Design and construction of a mechatronic robot with five degrees of freedom that locates internal porosity in centrifugal pumps

    Science.gov (United States)

    Bautista-Elivar, N.; Uribe-Fernández, U.; Ruiz-Conteras, F.; Santillan-Gutierrez, D.; Sánchez-Hernández, C.; Robledo-Sánchez, C.

    2009-09-01

    In this paper is presented construction and implementation of a mechatronic robot to obtain porosity in parts mechanics of centrifugal pumps using ultrasonic wave. Considerations about the methods applied and their use in the field of metrology for the metal mechanic industry are taken into consideration. This project is inserted in ITT Goulds Pumps industries, with a headquarter in Tizayuca Hidalgo State, Mexico. A mechatronic robot with 5 free grades (XYZUV) of 170 X 104 X 120 cm controlled by a PC is built. The robot let us scan metal mechanic pieces of 120 X 90 X 170 cm. It is incorporated a sensor ultrasonic in miniature in the Z axis. Such arrangement allows applying the techniques of ultrasonic wave to obtain maps of porosity in parts mechanics in manufacturing pumps to test mechanic deformation. The scan is done by the Z axis when traveling around the piece under test with the objective of finding fragility zones when applying cutting efforts to the pieces.

  16. Characteristics of backflow vortex cavitation in screw centrifugal pump%螺旋离心泵内回流涡空化特性

    Institute of Scientific and Technical Information of China (English)

    邓育轩; 李仁年; 韩伟; 杨文洁; 李正贵; 张毅鹏

    2015-01-01

    Screw centrifugal pump has swirling backflow under a wide range of flow rates. The backflow vortex structure occurs in the shear layer between the main flow and the swirling backflow. The pressure at the core of a backflow vortex is lower than the ambient pressure due to the centrifugal force on the vertical flow which results in cavitation if the core pressure becomes lower than the vapor pressure. This is called backflow vortex cavitation. In order to study the backflow vortex cavitation, a screw centrifugal pump was designed for experimental studies. The clearance between vane rim and cover plate was 2.9 mm in this screw centrifugal pump. By using the high speed video picture, we observed two backflow vortex cavitation clouds extending upstream from the tip at the screw centrifugal pump inlet, covering a wide range of flow rates. We also found that under a certain net positive suction head (NPSH), i.e., when the flow rate was decreased, the volume of the two backflow vortex cavitation cloud was decreased. Experimental studies on the backflow vortex cavitation from this screw centrifugal pump have provided novel insight of the characteristics of backflow vortex cavitation, but the limited information has not lead to the complete understanding of the phenomena. In addition to blade surface and backflow vortex cavitations, tip leakage cavitation occurred for screw centrifugal pump with tip clearance. With these types of cavitation, the flow in a screw centrifugal pump presented a very complicated three-dimensional structure. Since experiment results give limited information, numerical simulation plays an important role to further understand such complicate flow phenomena. Using the CFD code, the fundamental characteristics of the backflow vortex cavitation was investigated in detail. It was found that the backflow vortices were formed in a circumferentially twisted manner at the boundary between the swirling backflow and the straight inlet flow. When the flow rate

  17. Numerical investigation of solid-liquid two phase flow in a non-clogging centrifugal pump at off-design conditions

    International Nuclear Information System (INIS)

    The solid-liquid two-phase flow fields in the non-clogging centrifugal pump with a double-channel impeller have been investigated numerically for the design condition and also off-design conditions, in order to study the solid-liquid two-phase flow pattern and non-clogging mechanism in non-clogging centrifugal pumps. The main conclusions include: The sand volume fraction distribution is extremely inhomogeneous in the whole flow channel of the pump at off-design conditions. In the impeller, particles mainly flow along the pressure surface and hub; In the volute, particles mainly accumulate in the region near to the exit of volute, the largest sand volume fraction is observed at the tongue, and a large number of particles collide with volute wall and exit the volute after circling around the volute for several times. When the particle diameter increases, particles tend to accumulate on the pressure side of the impeller, and more particles crash with the pressure side of the blade. And larger sand volume fraction gratitude is also observed in the whole flow channel of the pump. With the decrease of the inlet sand volume fraction, particles tend to accumulate on the suction side of the blade. Compared with the particle diameter, the inlet sand volume fraction has less influence on the sand volume fraction gratitude in the whole channel of the pump. At the large flow rate, the minimum and maximum sand volume fraction in the whole flow channel of the model pump tends to be smaller than that at the small flow rate. Thus, it is concluded that the water transportation capacity increases with the flow rate. This research will strengthen people's understanding of the multiphase flow pattern in non-clogging centrifugal pumps, thus provides a theoretical basis for the optimal design of non-clogging centrifugal pumps.

  18. Centrifugal and electric field forces dual-pumping CD-like microfluidic platform for biomedical separation.

    Science.gov (United States)

    Wang, Gou-Jen; Hsu, Wen-Haw; Chang, Yau-Zin; Yang, Hsiharng

    2004-03-01

    In this article, we propose a versatile CD-like multi-channel electrophoresis-based biomedical separation system that is driven by the interactive forces between the centrifugal force and the electric field force. The centrifugal force control of this system is realized through the velocity control of a DC servo motor, while the electric field is governed through the concentric conducting circuits, which are suitably designed and fabricated by sputtering on metal mask method, and can be adjusted to provide multi-stage voltages. Experimental results demonstrate that the electro-osmotic flow (EOF) effect can be effectively reduced when the electric field force and centrifugal force are in the opposite direction. Benefits from this are that the electrophoresis separation time can be prolonged and the length of the microfluidic channels can be shortened; therefore, more effective separation efficiency can be obtained. Moreover, other advantages, such as lower joule-heat generation, low-chemistry reaction, and no variation on the ion concentration during processes, make this biomedical separation system more useful. PMID:15307444

  19. The influence of the flow rate on periodic flow unsteadiness behaviors in a sewage centrifugal pump

    Institute of Scientific and Technical Information of China (English)

    裴吉; 袁寿其; 袁建平; 王文杰

    2013-01-01

    To design a single-blade pump with a good performance in a wide operational range and to increase the pump reliability in the multi-conditional hydraulic design process, an understanding of the unsteady flow behaviors as related with the flow rate is very important. However, the traditional design often considers only a single design condition, and the unsteady flow behaviors have not been well studied for single-blade pumps under different conditions. A comparison analysis of the flow unsteadiness behaviors at di-fferent flow rates within the whole flow passage of the pump is carried out in this paper by solving the three-dimensional unsteady Reynolds-averaged Navier-Stokes equations with the Shear Stress Transport (SST) turbulence model. A definition of the unsteadi-ness in the pump is made and applied to analyze the unsteady intensity distributions, and the flow rate effect on the complex unsteady flow in the pump is studied quantitatively while the flow mechanism is also analyzed. The CFD results are validated by experimental data collected at the laboratory. It is shown that a significant flow rate effect on the time-averaged unsteadiness and the turbulence in-tensity distribution can be observed in both rotor and stator domains including the side chamber. The findings would be useful to re-duce the flow unsteadiness and to increase the pump reliability under multi-conditions.

  20. CFD Analysis of a Centrifugal Pump with Supercritical Carbon Dioxide as a Working Fluid

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Gu; Lee, Jeong Ik; Ahn, Yoonhan; Lee, Jekyoung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Cha, Jae Eun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Addad, Yacine [Khalifa Univ. of Science Technology and Research, Abu Dhabi (United Arab Emirates)

    2013-05-15

    The research team is conducting a S-CO{sub 2} pump experiment to obtain fundamental data for the advanced pump design and measure the overall performance of the pump near the critical point. The S-CO{sub 2} pump testing loop configuration is similar to SNL and JAEA testing loop while the operating conditions and focus of experiment are different from other test facilities. This paper presents the methodology of a 3-dimensional flow analysis for the S-CO{sub 2} pump by using the commercial CFD code. In Figure 2, the results at the 1.5kg/s mass flow rate seems to be close agreement between the CFD efficiency and S-CO{sub 2} test results. In the low mass flow rate of 1.0kg/s, CFD predicted 17∼25% higher efficiency than the test result. In the real test facility, the steel structure of pump is not an adiabatic wall and also the mechanical losses such as suction, blade loading and leakage exist in the pump. The reason why CFD analysis showed higher pump efficiency at the low mass flow is the above mentioned losses were excluded from the model. However, as the mass flow rate increases these have less effect on the efficiency. If the heat transfer through the structure and pump losses are applied in the analysis, other losses can be estimated. From the S-CO{sub 2} pump experiment, more data will be obtained and compared to the CFD analyses under the methodology presented in this paper. After the fluid behavior in the pump are well understood, these analysis results will be used for optimizing impeller for advanced S-CO{sub 2} compressor design in the future. However, it is very encouraging that even at very small mass flow rate the efficiency of S-CO{sub 2} pump near the critical point operation is very high compared to the manufacturer water test. The reason behind such phenomenon will be more carefully studied in the future.

  1. Advancement Research of Foreign Centrifugal Pump Technical Standards%国外离心泵技术标准先进性研究

    Institute of Scientific and Technical Information of China (English)

    丁俊刚

    2014-01-01

    In order to decrease failure rate and maintenance cost of centrifugal pumps, domestic and international operation and maintenance standards for centrifugal pumps were roundly classified. In allusion to design and installation and operation and management and maintenance and repair of centrifugal pumps, difference between domestic and international technology standards of centrifugal pumps were studied in detail. The advancement of Russia standards and American standards and ISO standards were systematacially expounded, including connection requirements of pumps and inlet/outlet pipeline, and logical control relationship for pumps house vent systems, and pumps base sinking inspection, and pumps emergency shutdown conditions, and pumps inspection and maintenance periods, and vibration and speed for bearing box and pumps shaft. Finally, by means of learning foreign standards, recommendations are made to raise the level of centrifugal pumps operation and management standards and strength the work of standards revision and development.%为了减少离心泵故障率,降低维护成本,全面梳理了国内外离心泵运行管理标准。从离心泵设计安装、运行管理和维护修理等三个方面,深入研究了国内外离心泵技术标准国的差异。系统阐述了俄罗斯标准、美国标准和ISO标准的先进性,包括泵与出入口管道的连接要求、泵房通风系统控制逻辑关系、泵基础下陷情况监测、泵紧急停车的情形、泵检测维修周期以及泵轴承箱和泵轴的振动幅度和速度限制等。最后,针对借鉴国外标准先进理念,提高我国离心泵运行管理标准水平,以及加强标准制修订工作,提出了建议。

  2. Unsteady measurement of the static pressure on the impeller blade surfaces and optical observation on centrifugal pumps under varying liquid/gas two-phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Suryawijaya, P.; Kosyna, G. [Pfleiderer-Inst. fuer Stroemungsmaschinen, Technische Univ. Braunschweig, Braunschweig (Germany)

    2003-03-01

    A liquid/gas two-phase flow (liquid contains undissolved gas) can be found in a wide range of pump applications, especially in chemical industries, off-shore oil production and nuclear reactors. It is well known that the performance of single stage centrifugal pumps decreases rapidly under liquid/gas two-phase flow conditions. The consequences of entrained gas depend on the relative amount of gas and liquid present, and vary from a slight deterioration on performance up to complete blockage known as ''gas locking''. Before gas locking occurs, other phenomena such as pump head degradation, surging and ''gas blocking'' take place. For two-phase flow applications of centrifugal pump the influence of the entrained gas on pump behaviour must be predictable. This is a hard task due to the complexity involved in modelling multiphase flow inside turbomachines. An accurate prediction of the performance for any pump handling liquid/gas mixture is still a problem today. This paper reports on a research project, carried out at the Pfleiderer-Institute for Turbomachinery, Technical University of Braunschweig, Germany. The purpose of this project is to get a better understanding of the physical background of the two-phase flow behaviour of the centrifugal pumps by measuring the static pressure on the impeller blade surfaces and by optical observation under varying two-phase flow conditions. The results will also be used to validate a numerical code, which is developed in a related research project. The project is focused on two centrifugal pumps, one scaled down from the other, having the same low specific speed number ns = 27. The pumps are operating under variable two-phase flow conditions. Air and water were used as working fluids. Flow structures within the pump impeller and the overall pump performance are investigated by numerical simulation and experiments. One impeller blade of the pump is equipped with eight KULITE trademark sub

  3. The Control Design of the Centrifugal Pump Dry Gas Seal%离心泵干气密封系统控制的设计

    Institute of Scientific and Technical Information of China (English)

    孙高攀

    2015-01-01

    This article aims at the defects existing in the micro sealing surface leakage of dry gas of centrifu⁃gal pump, according to the production practice of methanol to olefins, to design a kind of control method of centrifugal pump dry gas seal gas supply system, which can solve the defects of centrifugal pump dry gas sealing problems.%本文针对离心泵的干气密封面存在微泄漏的缺陷,结合甲醇制烯烃生产实践,设计出一种离心泵干气密封供气系统的控制方法,可解决离心泵干气密封泄露所产生的问题。

  4. Brief Analysis of Status and Trend of Domestic Plastic Centrifugal Pumps%浅析国产塑料离心泵现状及发展方向

    Institute of Scientific and Technical Information of China (English)

    杨晓斌

    2015-01-01

    The characteristics of the domestic plastic centrifugal pumps are described, especially the advantages and disadvantages of these pumps are analyzed from the aspects of material, structure, sealing, application and so on. Compared with the foreign advanced products, the development trend of the domestic plastic centrifugal pumps is then discussed.%分析了国产塑料离心泵的特点, 从材料、 结构、 密封和使用等多方面分析了其优劣性. 将国产塑料离心泵与国外先进产品进行了比较, 讨论了其未来发展方向.

  5. 离心泵干气密封系统控制的设计%The Control Design of the Centrifugal Pump Dry Gas Seal

    Institute of Scientific and Technical Information of China (English)

    孙高攀

    2015-01-01

    本文针对离心泵的干气密封面存在微泄漏的缺陷,结合甲醇制烯烃生产实践,设计出一种离心泵干气密封供气系统的控制方法,可解决离心泵干气密封泄露所产生的问题。%This article aims at the defects existing in the micro sealing surface leakage of dry gas of centrifu⁃gal pump, according to the production practice of methanol to olefins, to design a kind of control method of centrifugal pump dry gas seal gas supply system, which can solve the defects of centrifugal pump dry gas sealing problems.

  6. Validation of high-resolution gamma-ray computed tomography for quantitative gas holdup measurements in centrifugal pumps

    International Nuclear Information System (INIS)

    In this article, the capability of high-resolution gamma-ray computed tomography (HireCT) for quantitative gas–liquid phase distribution measurements in commercially available industrial pumps is experimentally investigated. The object of interest thereby operates under two-phase flow conditions. HireCT System comprises a collimated 137Cs isotopic source, a radiation detector arc with a multi-channel signal processing unit, and a rotary unit enabling CT scans of objects with diameters of up to 700 mm. The accuracy of gas holdup measurements was validated on a sophisticated modular test mockup replicating defined gas–liquid distributions, which are expected in impeller chambers of industrial centrifugal pumps under two-phase operation. Stationary as well as rotation-synchronized CT scanning techniques have been analyzed, which are both used to obtain sharply resolved gas phase distributions in rotating structures as well as non-rotating zones. A measuring accuracy of better than 1% absolute for variously distributed static gas holdups in the rotating frame has been verified with the modular test mockup using HireCT. (paper)

  7. Validation of high-resolution gamma-ray computed tomography for quantitative gas holdup measurements in centrifugal pumps

    Science.gov (United States)

    Bieberle, André; Schäfer, Thomas; Neumann, Martin; Hampel, Uwe

    2015-09-01

    In this article, the capability of high-resolution gamma-ray computed tomography (HireCT) for quantitative gas-liquid phase distribution measurements in commercially available industrial pumps is experimentally investigated. The object of interest thereby operates under two-phase flow conditions. HireCT System comprises a collimated 137Cs isotopic source, a radiation detector arc with a multi-channel signal processing unit, and a rotary unit enabling CT scans of objects with diameters of up to 700 mm. The accuracy of gas holdup measurements was validated on a sophisticated modular test mockup replicating defined gas-liquid distributions, which are expected in impeller chambers of industrial centrifugal pumps under two-phase operation. Stationary as well as rotation-synchronized CT scanning techniques have been analyzed, which are both used to obtain sharply resolved gas phase distributions in rotating structures as well as non-rotating zones. A measuring accuracy of better than 1% absolute for variously distributed static gas holdups in the rotating frame has been verified with the modular test mockup using HireCT.

  8. Effect of Centrifugal Pump Blade Inlet Geometry on Pump Cavitation Performance%离心泵的叶片进口几何形状对泵汽蚀性能的影响

    Institute of Scientific and Technical Information of China (English)

    张建华; 楚武利; 马文瑛

    2012-01-01

    为了改善离心泵内的汽蚀性能,以ZA150 -315石油化工离心泵为研究对象,在离心叶轮基本外尺寸和设计转速相同的情况下,以3种不同厚度变化规律构造3种离心泵叶轮,运用FLUENT软件进行数值模拟计算,得到了汽蚀发生时泵内部气-液两相分布规律和压力分布规律.分析表明:叶片进口段的形状影响泵的汽蚀性能.叶片进口段形状越接近流线型泵的抗汽蚀性能越好,加大叶片进口段曲率半径可以降低泵的汽蚀余量,改善泵的汽蚀性能.%In order to improve centrifugal pump cavitation performance, ZA150 - 315 petrochemical centrifugal pump were studied. With the basic exterior parameters and rotational speed of centrifugal impeller were fixed, centrifugal impellers were generated with three different changes of thickness, the vapor - liquid two - phase distribution and pressure distribution of centrifugal impeller inner flow were obtained by using computer fluid dynamic method. Analysis of simulated results demonstrate that, the blade inlet geometry have effect on pump cavitation performance. The geometry of the blade inlet closer to streamline, the better to the pump anti - cavitation performance, increasing the radius of curvature of the blade inlet section can reduce the pump cavitation allowance, improving pump cavitation performance.

  9. Prediction on the Reliability of A Low Specific Centrifugal Pump%低比转速化工离心泵的可靠性预测

    Institute of Scientific and Technical Information of China (English)

    夏雨鑫

    2014-01-01

    在化工离心泵设计过程中对泵的性能和可靠度进行预测有利于保证泵在运行过程中的可靠性。为给离心泵的可靠性设计提供一种分析手段,以一台低比转速离心泵为对象,给出该泵的设计参数和结构、对水力性能进行数值预测和性能测试。将离心泵看作一个由各部件组成的串联系统,在相关经验或试验数据基础上结合模型泵的特点,分析单元可靠度进而得到零件的失效率,最终通过系统的可靠度计算得出离心泵的可靠度。该设计和分析方法相对于传统的机械设计方法更有利与提高泵的可靠性。%The performance and reliability prediction in the design of the pump are helpful to ensure the reliability of the chemi-cal process pump during operation.to provide an analysis method for the reliability design for centrifugal pump,with a specific speed centrifugal pump as the research object,the design parameters and structure were given,the numerical and experimental results of the pump performance were presented.The centrifugal pump was modeled as a series system with various components. On the basis of the relevant experience,experimental data and the characteristic model of the centrifugal pump,the reliability and failure rate of the components was obtained,then the reliability of centrifugal pump was calculated through the calculation of reli-ability of system.The design and analysis method compared with the traditional mechanical design method has more advantageous and improves the reliability of the chemical process pump.

  10. Prediction of rotating stall within an impeller of a centrifugal pump based on spectral analysis of pressure and velocity data

    International Nuclear Information System (INIS)

    Experimental data, which was acquired in two centrifugal pumps and provided by Grundfos A/S, were analysed to determine if rotating stall could be detected from the velocity and pressure time series. The pressure data, which were uniformly acquired in time at high sample rates(10 kHz), were measured simultaneously in four adjacent di.user channels just downstream of the impeller outlet. The velocity data, which were non-uniformly sampled in time at fairly low rates(100 Hz to 3.5 kHz), were acquired either in or downstream of the impeller. Two di.erent methodologies were employed for detection of stall. The first method, which involved direct analysis of raw data, yielded qualitatively useful flow reversal information from the time series for the radial velocity. The second approach, which was based on power spectrum analysis of velocity and pressure data, could detect the onset and identify the frequency of rotating stall to a satisfactory extent in one of the two pumps. Nearly identical stall frequencies were observed in both velocity and pressure power spectra and this rotating stall phenomenon, which occurred at a very low frequency relative to the impeller speed, did not reveal any noticeable degree of sensitivity to the flow rate. In the other pump, where the available data was limited to velocity time series, the power spectrum analysis was successful in detecting stationary stall for a 6 bladed impeller but did not provide conclusive results for the existence of stall in the case of the 7 bladed impeller. Recommendations on the type of experimental data required for accurate detection of stall are provided based upon the present study

  11. Hazard Evaluation for a Salt Well Centrifugal Pump Design Using Service Water for Lubrication and Cooling

    International Nuclear Information System (INIS)

    This report documents the results of a preliminary hazard analysis (PHA) covering the new salt well pump design. The PHA identified ten hazardous conditions mapped to four analyzed accidents: flammable gas deflagrations, fire in contaminated area, tank failure due to excessive loads, and waste transfer leaks. This document also presents the results of the control decision/allocation process. A backflow preventer and associated limiting condition were assigned

  12. Research on blood pump application in continuous renal replacement therapy equipment%血泵在连续性血液净化设备中的应用研究

    Institute of Scientific and Technical Information of China (English)

    潘海鸿; 梁成业; 杨微; 段素强; 申毅莉; 马西良

    2008-01-01

    Blood bump is one of the most important components in continuous renal replacement therapy (CRRT) equipment. The characteristics and classification of blood bumps are reviewed and special attentions are paid to roller pump and centrifugal pump which are commonly used in CRRT. Mechanic structure and working principle of these two types of blood bump are introduced. Roller pump is easy to be accepted by manufactures due to its durability and facility. Advantages of centrifugal pump include small blood loss, big pressure buffer and high safety during operations. In this paper, the characteristics of these two types of blood pumps are comprehensively compared and analyzed from nine aspects in their practical applications. Then the reasons for less use of centrifugal pump in practical applications are discussed and future development direction of blood pump technology is prospected.%血泵是连续性血液净化设备(CRRT)中最重要部件之一.回顾CRRT机中所用血泵特点及其分类,重点介绍现代滚压泵和离心泵,分析这两类血泵的机械结构和工作原理.因滚压式血泵耐用、操作简便.故易被接受.离心泵主要优点是血液损失小、压力缓冲大、安全性高.从9个方面进行综合比较、分析离心泵与滚压泵在实际应用中各自特点,给出离心泵在实际应用中使用少的原因,并进一步展望未来血泵发展方向.

  13. Effects of blade number on hydrodynamic force perturbation on impeller of voute type centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Yutaka; Kikuyama, Koji; Maeda, Takao (Nagoya Univ., Faculty of Engineering, Nagoya, (Japan))

    1989-08-25

    Pressures in exit volute, hydrodynamic force perturbations and fluctuating pressure on a three-blade centrifugal impeller, were measured. Comparison of the forces between the three-and seven-blade impellers was made and the effects of the blade numbers on the hydrodynamic force were clarified. When an interval between the impeller outlet and the volute tongue is large, abrupt fluctuations, which are shown in pressures in exit volute at near the tonge, are relieved in the impeller outlet pressure. In the impeller channel, the amplitude of synchronous pressure fluctuation becomes large at near the outlet of impeller channel and the impeller front-edge. In comparison with the seven-blade impeller (normal blade number), there are few differences in the hydrodynamic force exerted on one blade. However, hydrodynamic force on the three-blade impeller exhibits a very large fluctuation. This is due to the fact that synchronous pressure fluctuation in the impeller exhibits a large fluctuation in lower component. 11 refs., 11 figs.

  14. Experimental investigation of the hydrodynamic forces on the shroud of a centrifugal pump impeller. Thesis

    Science.gov (United States)

    Zhuang, Fei

    1989-01-01

    Fluid-induced forces acting on a rotating impeller are known to cause rotor-dynamic problems in turbomachines. The forces generated by leakage flow along the front shroud surface of a centrifugal turbomachine impeller play an important role among these fluid-induced forces. The present research was aimed to gain a better understanding of these shroud forces. An experimental apparatus was designed and constructed to simulate the impeller shroud leakage flow. Hydrodynamic forces and steady and unsteady pressure distributions on the rotating shroud were measured as functions of eccentricity, width of shroud clearance, face seal clearance and shaft rotating speed. The forces measured from the dynamometer and manometers agreed well. The hydrodynamic force matrices were found skew-symmetric and statically unstable. This is qualitatively similar to the result of previous hydrodynamic volute force measurements. Nondimensionalized normal and tangential forces decrease slightly as Reynolds number increases. As the width of the shroud clearance decreases and/or the eccentricity increases, the hydrodynamic forces increase nonlinearly. There was some evidence found that increased front seal clearance could reduce the radial shroud forces and the relative magnitude of the destabilizing tangential force. Subharmonic pressure fluctuations were also observed which may adversely affect the behavior of the rotor system.

  15. Improving the Hydraulic Efficiency of Centrifugal Pumps through Computational Fluid Dynamics Based Design optimization

    Directory of Open Access Journals (Sweden)

    Abdellah Ait moussa

    2014-08-01

    Full Text Available The design and optimization of turbo machine impellers such as those in pumps and turbines is a highly complicated task due to the complex three-dimensional shape of the impeller blades and surrounding devices. Small differences in geometry can lead to significant changes in the performance of these machines. We report here an efficient numerical technique that automatically optimizes the geometry of these blades for maximum performance. The technique combines, mathematical modeling of the impeller blades using non-uniform rational B-spline (NURBS, Computational fluid dynamics (CFD with Geometry Parameterizations in turbulent flow simulation and the Globalized and bounded Nelder-Mead (GBNM algorithm in geometry optimization.

  16. Variations in Battery Life of a Heart—Lung Machine Using Different Pump Speeds, Pressure Loads, Boot Material, Centrifugal Pump Head, Multiple Pump Usage, and Battery Age

    OpenAIRE

    Marshall, Cornelius; Hargrove, Martin; O’Donnell, Aonghus; Aherne, Thomas

    2005-01-01

    Electrical failure during cardiopulmonary bypass (CPB) has previously been reported to occur in 1 of every 1500 cases. Most heart—lung machine pump consoles are equipped with built-in battery back-up units. Battery run times of these devices are variable and have not been reported. Different conditions of use can extend battery life in the event of electrical failure. This study was designed to examine the run time of a fully charged battery under various conditions of pump speed, pressure lo...

  17. Study on solid-liquid two-phase unsteady flow characteristics with different flow rates in screw centrifugal pump

    International Nuclear Information System (INIS)

    The screw centrifugal pump is used as an object, and the unsteady numerical simulation of solid-liquid two-phase flow is carried out under different flow rate conditions in one circle by choosing the two-phase flow of sand and water as medium, using the software FLUENT based on the URANS equations, combining with sliding mesh method, and choosing the Mixture multiphase flow model and the SIMPLE algorithm. The results show that, with the flow rate increasing, the change trends for the pressure on volute outlet are almost constant, the fluctuation trends of the impeller axial force have a little change, the pressure and the axial force turn to decrease on the whole, the radial force gradually increases when the impeller maximum radius passes by half a cycle near the volute outlet, and the radial force gradually decreases when the maximum radius passes by the other half a cycle in a rotation cycle. The distributions of the solid particles are very uneven under a small flow rate condition on the face. The solid particles under a big flow rate condition are distributed more evenly than the ones under a small flow rate condition on the back. The theoretical basis and reference are provided for improving its working performance

  18. An Experimental Study on the Fluid Forces Induced by Rotor-Stator Interaction in a Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Shijie Guo

    2003-01-01

    Full Text Available The pressure fluctuations and the radial fluid forces acting on the impeller, the pressures in the volute, as well as the vibration of the shaft in a centrifugal pump were measured simultaneously, and their relationship was investigated. Experiments were done for various diffuser vanes, flow rates, and rotating speeds. It was demonstrated that both the blade-pressure fluctuations and the volute static pressures are nonuniform circumferentially (not axisymmetrical under off-design operating conditions and that the two have a strong relationship. At high flow rates, the blade pressure fluctuations, induced by rotor-stator interactions, are large in areas where the volute static pressure is low. The traveling directions of the rotating pressure waves, the whirling directions of the radial fluid forces, and the most predominant frequency components of both the fluctuations and the forces are discussed, and an equation for predicting them is introduced. It was also noted that large alternating fluid forces are not necessarily associated with large pressure fluctuations. Furthermore, when measuring the radial fluid forces in the rotating frame, other frequency components, in addition to those related to the products of the diffuser vane number and the rotating frequency, may occur due to the circumferential unevenness of the pressure fluctuations on the impeller. These components are predictable.

  19. Numerical simulation of the effect of solid-volume fraction on induction force of screw centrifugal pump

    International Nuclear Information System (INIS)

    The solid-liquid two-phase unsteady flow in a screw centrifugal pump was simulated with unsteady Reynolds averaged Navier-Stokes equations and sliding mesh technology. The distribution of the pressure at volute outlet, radial force, axial force and total moment are presented in this paper. The effects of solid-phase volume fractions on the value and direction of the induction thrust are analyzed. Seven monitor points are arranged on the inner surface of volute along the impeller rotation. The characters of the induced force on the monitor points with different solid-phase volume fractions are investigated. The results indicated that different solid-volume fractions have litter effects on the trend and direction of pressure at volute, radial force, axial force and total moment during one period, but the value of induction forces increase with the increasing of solid-volume fraction; The pressure fluctuation on the monitor points has with different trends during one period, which depends on the direction of the monitor points and the rotor-stator interaction strength of impeller and volute. With the rotation of impeller, the values of pressure in the whole passage are further increased along the rotation direction with the role of impeller vane. Solid-phase volume fraction has few effects on change trend of induced thrust as radial force and axial force on the monitor points, but the values of pressure on the monitor points increase with the increasing of solid-volume fraction.

  20. Proposal of Unique Process Pump with Floating Type Centrifugal Impeller (Preliminarily Report : Axial Thrust of Impeller with Driving Shaft)

    Science.gov (United States)

    Kawashima, Ryunosuke; Kanemoto, Toshiaki; Sakamoto, Kengo; Uno, Mitsuo

    2010-06-01

    The authors have proposed the unique centrifugal pump, in which the impeller dose not have the driving shaft but is driven by the magnetic induction, namely Lorentz force, without the stay. Then, the rotating posture of the impeller is not stable, just like UFO. To make the rotating posture of the impeller stable irrespective of the operating condition, the pressure in the impeller casing was investigated experimentally while the impeller rotates at the steady state, as the preliminarily stage. The pressure, as well known, fluctuates periodically in response to the blade number. Besides, the pressure on the impeller shrouds decreases with the increase of the gap between the front shroud and the suction cover where the water leaks to the suction pipe, and is distorted in the peripheral direction. Such pressure conditions contribute directly to the hydraulic force acting on the impeller. The unstable behaviors of the impeller are induced from the above hydraulic forces, which change unsteadily in the radial and the peripheral directions in the impeller casing. The forces are affected by not only the operating condition but also the rotating posture of the impeller.

  1. The research on particle trajectory of solid-liquid two-phase flow and erosion predicting in screw centrifugal pump

    Science.gov (United States)

    Shen, Z. J.; Li, R. N.; Han, W.; Zhao, W. G.; Wang, X. H.

    2016-05-01

    Use the Discrete Phase Model (DPM) based on Euler-Lagrange method, the internal flow field of screw centrifugal pump was simulated by computational fluid dynamics(CFD) code when transmission medium is solid-liquid two phase flow with large-size particles. The research of liquid phase is under the Euler coordinate system while the solid phase is under the Lagrange coordinate system. The energy change, trajectory characteristic of solid phase particle and its erosion damage rule of solid-phase particle in whole computational domain is analyzed with different density, partical size(d=0.05mm, d=0.2mm, d=2mm) and solid volume fraction(Cv=3%, Cv=5%, Cv=7%).The result shows that within a given diameter range, the low density fine particles trajectory are longer, more collision times with flow passage components, more energy loss and the erosion parts are relatively uniform, but particles which are large-size diameter and high density has a big collision angle with the surface of impeller and volute, even the area of impact and abrasion are quite focus, and easy to be transported. particles will impact with the head of impeller when it enter into impeller domain, the erosion mainly occurs on the work side of impeller.

  2. Time-Frequency Characterization of Rotating Instabilities in a Centrifugal Pump with a Vaned Diffuser

    Directory of Open Access Journals (Sweden)

    G. Pavesi

    2008-01-01

    Full Text Available This paper presents acoustic and flowdynamic investigations of large-scale instabilities in a radial pump with a vaned diffuser. Pressure fluctuations were measured with transducers placed flush at the inlet duct, at the impeller discharge, and in the vane diffuser walls. Two impeller rotation speeds were analyzed in the study, at design, and at off-design flow rates. A spectral analysis was carried out on the pressure signals in frequency and in time-frequency domains to identified precursors, inception, and evolution of the pressure instabilities. The results highlighted the existence of a rotating pressure structure at the impeller discharge, having a fluid-dynamical origin and propagating both in the radial direction and inside the impeller. The experimental data were then compared with the results obtained with help of ANSYS CFX computer code; focusing on the changing flow field at part load. Turbulence was reproduced by DES model.

  3. Effects of volute geometry and impeller orbit on the hydraulic performance of a centrifugal pump

    Science.gov (United States)

    Flack, R. D.; Lanes, R. F.

    1983-01-01

    Overall performance data was taken for a Plexiglas water pump with a logarithmic spiral volute and rectangular cross sectioned flow channels. Parametric studies were made in which the center of the impeller was offset from the design center of the volute. The rig was also designed such that the impeller was allowed to synchronously orbit by a fixed amount about any center. The studies indicate that decreasing the tongue clearance decreases the head at low flowrates and increases the head at high flowrates. Also, decreasing the volute area in the first half of the volute and holding the tongue clearance the same, resulted in a decreased head for low flowrates but performance at high flowrates was not affected. Finally, the overall hydraulic performance was not affected by the impeller orbitting about the volute center.

  4. 基于Visual Basic编程对离心泵性能曲线的拟合%Fitting Centrifugal Pump Performance Curve Based on Visual Basic

    Institute of Scientific and Technical Information of China (English)

    刘红明; 孙铁; 刘嵩; 王亮; 魏佳广

    2014-01-01

    在分析拟合离心泵性能曲线必要性的基础上,以拟合离心泵流量和扬程性能曲线为例,介绍了利用最小二乘法使用visual Basic语言进行直接编程拟合曲线的方法;经实际使用本程序具有简单、易用、求解效率高、适用范围广等特点,有效解决了石化行业中离心泵选型、试验中曲线拟合的数据处理问题,可以在离心泵及容积泵性能曲线拟合中推广应用。%Centrifugal pump performance curve is the basis of measuring the performance, type selection calculation and optimal operation of the centrifugal pump. After the test,in order to get more accurate data based on the sampling point, curve of experimental data needs to be fitted. In this paper, taking fitting flow and head curve of centrifugal pump as an example, the method to fit the curve by programming based visual basic with the least square method was introduced. The practical application has proved that the method has many advantages, and can effectively solve data processing problems in centrifugal pump type selection and curve fitting in petrochemical industry.

  5. Mathematical model of the two-phase flow in a vertical well with an electric centrifugal pump located in the permafrost region

    Science.gov (United States)

    Musakaev, N. G.; Borodin, S. L.

    2016-05-01

    The mathematical model of the two-phase flow in a vertical well with an electric centrifugal pump located in the permafrost region is presented. The comparison of the calculation's results with experimental data, the results of numerical experiments by determining the flow structure, the temperature distribution in a well, influence of the temperature distribution on paraffin deposition and change in time of the radius of thawing in the frozen ground are presented.

  6. Haemolysis following rapid experimental red blood cell transfusion--an evaluation of two infusion pumps

    DEFF Research Database (Denmark)

    Hansen, Tom Giedsing; Sprogøe-Jakobsen, U; Pedersen, C M;

    1998-01-01

    The vast majority of infusion pumps used for rapid transfusion of large amounts of blood have never been properly examined regarding their influence on the quality of the red blood cells (RBCs) infused. In this study, we evaluated the effect of two different infusion pumps on the degree of RBC...

  7. Biochemical assessment of growth factors and circulation of blood components contained in the different fractions obtained by centrifugation of venous blood.

    Science.gov (United States)

    Corigiano, M; Ciobanu, G; Baldoni, E; Pompa, G

    2014-01-01

    The aim of this study was to evaluate a biochemical marker with different elements of a normal blood serum and centrifuged blood serum after a different rotation system. For this technique, we used five fractions of a blood Concentrated Growth Factors system (bCGF) and a particular device for the different rotation program. Blood samples were collected from 10 volunteers aged between 35 and 55 in the Operative Unit of the “Sapienza” University of Rome with only a fraction of different biochemical elements. Through an individual blood phase separator tube of venous blood, active factions of serum and 4 fractions of red buffy coat were taken. The biochemical markers with 14 elements were examined at times: P1-11 minutes, P2-12minutes, P3-15 minutes. Exclusively biological materials which are normally applied in the regeneration techniques for different defects and lesions were used with this technique. After specific rotation programs, a different result was obtained for each cycle: P1, P2, P3. In test tubes obtained by separated blood, we observed a higher concentration of proteins, ions, and other antigens compared to normal blood plasma. Examining the biochemical results of different elements, we observed an increase (P≤0,01). Since each person’s DNA is different, we could not have the same results in 5 fractions of blood concentration, we did, however, find a good increase in only a fraction of proteins, immunoglobulin and different ions. We obtained five fractions after centrifugation, and we had an increase in different biochemical elements compared to normal blood (P≤0,01) which is significant at different times. These biochemical elements were stimulated by different growth factors, which are used by the immune system, and they induced the formation of hard and soft tissues and good regeneration. PMID:25001662

  8. Control Method of a Rotary Blood Pump for a Left Ventricular Assist Device

    OpenAIRE

    Petukhov, D. S.; D.V. Telyshev; S.V. Selishchev

    2016-01-01

    The aim of the investigation is to develop a control method of a rotary blood pump (RBP) to solve the following problems: estimation of the pump flow rate, achievement and maintaining of the desired flow level through the continuous adjustment of pump speed and prevention of adverse effects on the cardiovascular system. Results. Functional chart of RBP control consists of several units: a unit for evaluation of instantaneous pump flow rate, unit for estimation of approximate and a...

  9. The effects of residual pump blood on patient plasma free haemoglobin levels post cardiac surgery.

    Science.gov (United States)

    H, Schotola; Aj, Wetz; Af, Popov; I, Bergmann; Bc, Danner; Fa, Schöndube; M, Bauer; A, Bräuer

    2016-09-01

    At the end of cardiopulmonary bypass, there are invariably several hundred millilitres of residual pump blood in the reservoir, which can either be re-transfused or discarded. The objective of this prospective observational study was to investigate the quality of the residual pump blood, focusing on plasma free haemoglobin (pfHb) and blood cell counts. Fifty-one consecutive patients were included in the study. Forty-nine units of residual pump blood and 58 units of transfused red blood cell (RBC) concentrates were analysed. The mean preoperative pfHb of the patients was 0.057 ± 0.062 g/l, which increased gradually to 0.55 ± 0.36 g/l on arrival in the intensive care unit postoperatively. On the first postoperative day, the mean pfHb had returned to within the normal range. Our data showed that haemoglobin, haematocrit, and erythrocyte counts of residual pump blood were approximately 40% of the values in standardised RBC concentrates. Plasma free haemoglobin was significantly higher in residual pump blood compared to RBC concentrates, and nearly twice as high as the pfHb in patient blood samples taken contemporaneously. Our findings indicate that residual pump blood pfHb levels are markedly higher compared to patients' blood and RBC concentrates, but that its administration does not significantly increase patients' pfHb levels. PMID:27608341

  10. Force and torque characteristics for magnetically driven blood pump

    Science.gov (United States)

    Zheng, Pan; Haik, Yousef; Kilani, Mohammad; Chen, Ching-Jen

    2002-03-01

    Magnetically driven screw pumps were designed and fabricated for pumping biological fluids. The magnetic field simulations for three different magnetic coupling arrangements were obtained numerically. The force and torque for the three arrangements were computed. The effect of the separation gap between poles and the rotational angle on the force and torque is also presented. The pump characteristics were obtained experimentally.

  11. Particle image velocimetry experimental and computational investigation of a blood pump

    Science.gov (United States)

    Yang, Xiaochen; Gui, Xingmin; Huang, Hui; Shen, Yongbin; Yu, Ziwen; Zhang, Yan

    2012-06-01

    Blood pumps have been adopted to treat heart failure over the past decades. A novel blood pump adopting the rotor with splitter blades and tandem cascade stator was developed recently. A particle image velocimetry (PIV) experiment was carried out to verify the design of the blood pump based on computational fluid dynamics (CFD) and further analyze the flow properties in the rotor and stator. The original sized pump model with an acrylic housing and an experiment loop were constructed to perform the optical measurement. The PIV testing was carried out at the rotational speed of 6952±50 r/min with the flow rate of 3.1 l/min and at 8186±50 r/min with 3.5 l/min, respectively. The velocity and the Reynolds shear stress distributions were investigated by PIV and CFD, and the comparisons between them will be helpful for the future blood pump design.

  12. The Tin Coatings Utilisation As Blood Contact Surface Modification In Implantable Rotary Left Ventricle Assist Device Religaheart Rot

    OpenAIRE

    Kustosz R.; Altyntsev I.; Darlak M.; Wierzchoń T.; Tarnowski M.; Gawlikowski M.; Gonsior M.; Kościelniak-Ziemniak M.

    2015-01-01

    Constructions of the mechanical-bearingless centrifugal blood pumps utilize different types of non-contact physical bearings, which allows to balance the forces that have an impact on the pump impeller, stabilizing its position in the pump house without wall contact. The paper presents investigations of the hybrid (passive magnetic bearings and hydrodynamic bearings) suspension system for the centrifugal blood pump. Numerical simulations were used to evaluate the hydrodynamic bearing lifting ...

  13. Three-dimensional calculation of air-water two-phase flow in a centrifugal pump based on a bubbly flow model with fixed cavity

    International Nuclear Information System (INIS)

    To predict the behavior of air-water two-phase flows in centrifugal pumps, we have proposed a three-dimensional numerical method on the basis of an inviscid bubbly flow model with slippage between two phases. The void fractions calculated distribute unevenly and their maximum exceeds an applicability of the model. To extend its applicability, a newly modified model is proposed in this paper by assuming that the bubbles in such high void fraction regions coalesce with each other and adhere to the neighboring impeller walls so as to form a fixed cavity. Using this model, the flows in a radial-flow pump are solved. The cavity obtained increases progressively from the shroud to the hub in the section just after the impeller inlet when the inlet void fraction exceeds a critical value and finally fills the section, showing close relation with the experiments when the pump loses its function due to an air-filled blockade. (author)

  14. Application of a compressible flow solver and barotropic cavitation model for the evaluation of the suction head in a low specific speed centrifugal pump impeller channel

    Science.gov (United States)

    Limbach, P.; Müller, T.; Skoda, R.

    2015-12-01

    Commonly, for the simulation of cavitation in centrifugal pumps incompressible flow solvers with VOF kind cavitation models are applied. Since the source/sink terms of the void fraction transport equation are based on simplified bubble dynamics, empirical parameters may need to be adjusted to the particular pump operating point. In the present study a barotropic cavitation model, which is based solely on thermodynamic fluid properties and does not include any empirical parameters, is applied on a single flow channel of a pump impeller in combination with a time-explicit viscous compressible flow solver. The suction head curves (head drop) are compared to the results of an incompressible implicit standard industrial CFD tool and are predicted qualitatively correct by the barotropic model.

  15. VENTRICLE ASSIST DEVICE: PAST, PRESENT, AND FUTURE NONPULSATILE PUMPS

    Directory of Open Access Journals (Sweden)

    G. Р. Itkin

    2009-01-01

    Full Text Available The article briefly describes the history of the non-pulsating type blood pumps for ventricular assist circulation and heart-lung machine. Disclosed the main advantages of these pumps before pulsating type, especially for implantable systems development. However, disadvantages of these pumps and the directions of minimize or eliminate ones have shown. Specific examples of our implantable centrifugal and axial pump developments are presented. Declare the ways to further improve the pumps

  16. Computational Fluid Dynamics-Based Design Optimization Method for Archimedes Screw Blood Pumps.

    Science.gov (United States)

    Yu, Hai; Janiga, Gábor; Thévenin, Dominique

    2016-04-01

    An optimization method suitable for improving the performance of Archimedes screw axial rotary blood pumps is described in the present article. In order to achieve a more robust design and to save computational resources, this method combines the advantages of the established pump design theory with modern computer-aided, computational fluid dynamics (CFD)-based design optimization (CFD-O) relying on evolutionary algorithms and computational fluid dynamics. The main purposes of this project are to: (i) integrate pump design theory within the already existing CFD-based optimization; (ii) demonstrate that the resulting procedure is suitable for optimizing an Archimedes screw blood pump in terms of efficiency. Results obtained in this study demonstrate that the developed tool is able to meet both objectives. Finally, the resulting level of hemolysis can be numerically assessed for the optimal design, as hemolysis is an issue of overwhelming importance for blood pumps. PMID:26526039

  17. Test Results of a 1.2 kg/s Centrifugal Liquid Helium Pump for the ATLAS Superconducting Toroid Magnet System

    CERN Document Server

    Pengo, R; Passardi, Giorgio; Pirotte, O; ten Kate, H H J

    2002-01-01

    The toroid superconducting magnet of ATLAS-LHC experiment at CERN will be indirectly cooled by means of forced flow of liquid helium at about 4.5 K. A centrifugal pump will be used, providing a mass flow of 1.2 kg/s and a differential pressure of 40 kPa (ca. 400 mbar) at about 4300 rpm. Two pumps are foreseen, one for redundancy, in order to feed in parallel the cooling circuits of the Barrel and the two End-Caps toroid magnets. The paper describes the tests carried out at CERN to measure the characteristic curves, i.e. the head versus the mass flow at different rotational speeds, as well as the pump total efficiency. The pump is of the "fullemission" type, i.e. with curved blades and it is equipped with an exchangeable inducer. A dedicated pump test facility has been constructed at CERN, which includes a Coriolis-type liquid helium mass flow meter. This facility is connected to the helium refrigerator used for the tests at CERN of the racetrack magnets of the Barrel and of the End-Cap toroids.

  18. The CFD Analysis of Centrifugal Pump for FlotationBased on Fluent Sliding Mesh%基于FLUENT滑移网格的浮选离心叶片泵内流场的CFD分析

    Institute of Scientific and Technical Information of China (English)

    李梦君; 李浙昆; 熊勇; 葛凌志

    2011-01-01

    The performance of centrifugal pump have an important influence on the stability and efficient of flotation process in equipment of flotation. In order to catch the variation of flow field inside of centrifugal pump, the sliding mesh technology in fluent software is used to numerically simulate the flow in centrifugal pump, and then * analyzed the flow variation inside of centrifugal pump with vane rotating, and obtain the total pressure graphs, velocity - vector graphs and turbulent kinetic energy graphs. Thus lays the foundation for the design and the structure optimization of centrifugal pump.%在浮选设备中离心泵的性能对浮选过程的平稳性和效率有着重要影响.为了准确掌握离心泵内部流场的变化情况,运用FLUENT软件中的滑移网格技术对叶片武离心泵进行流场动态数值模拟.分析得出叶片旋转情况下内部流场不同时间点的总压力图、速度矢量图和湍动能图,为离心泵的设计和优化奠定基础.

  19. Elementary theory of synchronous arterio-arterial blood pumps

    Science.gov (United States)

    Jones, R. T.; Petscheck, H. E.; Kantrowitz, A. R.

    1976-01-01

    In the technique of arterio-arterial pumping, a volume of fluid is withdrawn from the aorta during systole and reinjected during diastole, thereby reducing the systolic pressure of the heart and adding energy to the systemic circulation. It is found that an upper bound for the effectiveness of such devices is given by a formula that considers stroke output of the unaided heart and the increment caused by the pump with a stroke. The division of effort of the pump between the reduction of pressure and the increase of flow depends on the physiological mechanical impedance of the heart. The total effect is, however, independent of the impedance.

  20. Computational fluid dynamics modeling and hemolysis analysis of axial blood pumps with various impeller structures

    Institute of Scientific and Technical Information of China (English)

    XIA Dongdong; ZHAO Chunzhang; ZHANG Xiwen; BAI Jing

    2006-01-01

    The flow fields in the blood pump were analyzed three-dimensionally using computational fluid dynamics (CFD).Hemolysis of the pump was calculated based on the changes in shear stress and related exposure times along the particle trace lines using a forward Euler approach. In this way, how different impeller structures and rotational speeds affect the hemolysis was particularly acquired. As a result, impeller with long-short alternant vanes behaved best in hemolysis property and can be utilized to axial blood pumps' development and design.

  1. Three-dimensional calculation of air-water two-phase flow in centrifugal pump impeller based on a bubbly flow model

    International Nuclear Information System (INIS)

    To predict the behavior of gas-liquid two-phase flows in a centrifugal pump impeller, a three-dimensional numerical method is proposed on the basis of a bubbly flow model. Under the assumption of homogeneous bubbly flow entraining fine bubbles, the equation of motion of the mixture is represented by that of liquid-phase and the liquid velocity is expressed as a potential for a quasi-harmonic equation. This equation is solved with a finite element method to obtain the velocities, and the equation of motion of an air bubble is integrated numerically in the flow field to obtain the void fraction. These calculations are iterated to obtain a converged solution. The method has been applied to a radial-flow pump, and the results obtained have been confirmed by experiments within the range of bubbly flow regime

  2. Simulating of single phase flow in typical centrifugal pumps oil industry; Simulacao do escoamento monofasico em bombas centrifugas tipicas da industria do petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Ana Carla Costa; Silva, Aldrey Luis Morais da; Maitelli, Carla Wilza Souza de Paula [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2012-07-01

    With the various techniques applied in production processes and oil exploration, has been using the artificial lift equipment with the aim of promoting an increase in flow in oil wells and gas. Choosing the most appropriate method of elevation depends on certain factors, among them the initial costs of installation, maintenance and conditions in the producing field, resulting in a more precise analysis of the project. Although there are other methods that represent a low cost and easy maintenance, the BCS method (Electrical Submersible Pumping), appears to be quite effective when it is intended to pump more flow of liquids from both terrestrial and marine environments, in conditions adverse temperature, presence of free gas in the mixture and viscous fluids. This method is based in most cases where the vessel pressure was low, and the fluid does not reach the surface without intervention of an artificial means which can lift them. Similar happens at the end of productive life of a resurgence for the well, or even when the flow of it is far below what is expected to produce, requiring a complement of natural energy through artificial lift. By definition, the BCS is a method of artificial lift in which a subsurface electric motor turns electrical energy into mechanical centrifugal pump and a multistage overlapping converts mechanical energy into kinetic energy of the engine bringing the fluid surface. In this study we performed computer simulations using a commercial program ANSYS #Registered Sign# CFX #Registered Sign# dimensions previously obtained by the 3D geometry in CAD format, with the objective of evaluating the single-phase flow inside typical centrifugal pump submerged in the oil industry. The variable measured was the height of elevation and drilling fluids are oil and water.(author)

  3. Research on the Energy Consumption Evaluation and Energy Saving Technical Reconstruction of Centrifugal Pump System Based on Actual Demand

    OpenAIRE

    Luo Yin; Shouqi Yuan; Tang Yue; Yuan Jianping

    2013-01-01

    A new method for calculating the operational efficiency of a pumping station has been developed based on the integral principle and operation rules of the pump flow rate. To determine the energy saving space of a pumping system and to reflect the relationship between supply and demand, a new method for evaluating the energy consumption rate of a pump system has been developed based on the principle of an inverter-controlled water supply with varying pressures. These methods have been applied ...

  4. The Application of HB2 Centrifugal Pump in the Acetic Acid Distillation Section%HB2离心泵在醋酸精馏工段中的应用

    Institute of Scientific and Technical Information of China (English)

    乔豪杰

    2012-01-01

    在醋酸精馏工段中,大量HB2合金离心泵应用到高温高浓度醋酸中,而选用机械密封的离心泵在使用过程中,机械密封经常泄露,使用寿命较短。介绍了一种能够有效延长HB2离心泵机械密封使用寿命的方法。%In the acetic acid distillation process, a large number of HB2 alloy centrifugal pump applied to the high temperature and high concentration acetic acid condition. The mechanical seal could always leak when the centrifugal pump was used , and only had short service life. Introduced a kind of method that could prolong the service life of HB2 centrifugal pump mechanical seal effectively.

  5. Evaluation of Flow-Induced Dynamic Stress and Vibration of Volute Casing for a Large-Scale Double-Suction Centrifugal Pump

    Directory of Open Access Journals (Sweden)

    Fu-Jun Wang

    2013-01-01

    Full Text Available The transient analysis was carried out to investigate the dynamic stress and vibration of volute casing for a large double-suction centrifugal pump by using the transient fluid-structure interaction theory. The flow pulsations at flow rate ranging from 60% to 100% of the nominal flow rate (Qd were taken as the boundary conditions for FEM analysis of the pump volute casing structure. The results revealed that, for all operating conditions, the maximum stress located at the volute tongue region, whereas the maximum vibration displacement happened close to the shaft hole region. It was also found that the blade passing frequency and its harmonics were dominant in the variations of dynamic stress and vibration displacement. The amplitude of the dominant frequency for the maximum stress detected at 0.6 Qd was 1.14 times that at Qd, lower than the related difference observed for pressure fluctuations (3.23 times. This study provides an effective method to quantify the flow-induced structural dynamic characteristics for a large-scale double-suction pump. It can be used to direct the hydraulic and structural design and stable operation, as well as fatigue life prediction for large-scale pumps.

  6. 基于LabVIEW的离心泵闭环恒压控制特性试验%Experiment of Constant Pressure Control Characteristics for Centrifugal Pump

    Institute of Scientific and Technical Information of China (English)

    汤跃; 黄志攀; 汤玲迪; 梅星新

    2013-01-01

    利用虚拟仪器构建了基于变频器内置PID控制器的离心泵恒压闭环控制测试系统,将泵系统出口端改造成3个球阀的出口形式,能定量快速地改变工况,实现了近似阶跃的输入扰动.编写LabVIEW测试程序对离心泵恒压控制特性进行了试验研究,得出了离心泵恒压控制系统给定压力的设置范围,通过比较恒参数PID控制在不同工况变化下的控制性能,发现恒参数PID控制在工况变化较快和较大时,控制性能不理想;通过分析同一工况下恒参数PID和变参数PID的控制性能,得出变参数PID控制能更好地适应离心泵恒压控制系统.%In order to investigate the constant pressure control characteristics of centrifugal pump, a testing system on constant pressure closed-loop control of centrifugal pump water-supply system, which was based on internal PID controller of frequency converter was set up by using the virtual instrument. An innovative form of the outlet of the pump system composed of three ball valves was remodeled. It could change working condition quantitatively and rapidly. The outlet could create similar step disturbance. A LabVIEW test program was compiled to do research on control characteristics of constant pressure centrifugal pump system. The set range of the given pressure of the constant pressure control system was concluded. Contrasting the control characteristics of the fixed parameter PID regulator under different working conditions, it is showed that the control characteristics of the fixed parameter PID regulator are not good under the working conditions that changes quickly and extensively. Analyzing the control characteristics of the fixed parameter PID regulator and the variable parameter PID regulator under the same working condition, it is discovered that the variable parameter PID regulator is more applicable for the constant pressure control system.

  7. The simulation of multiphase flow field in implantable blood pump and analysis of hemolytic capability

    Institute of Scientific and Technical Information of China (English)

    LI Tie-yan; YE Liang; HONG Fang-wen; LIU Deng-cheng; FAN Hui-min; LIU Zhong-min

    2013-01-01

    The numerical simulation of the axial flow impeller blood pump NIVADIII is carried out by using a CFD multiphase flow model.The hydrodynamic performance of the pump and the flow field in the pump are analyzed,and the shear stress distribution is obtained.A hemolytic prediction model based on the shear stress is built based on the calculation results,and it can be used for quantitative predictions of the hemolytic behavior of a blood pump.Hemolysis tests in vitro were performed 6 times with fresh bovine blood.At each time,the flow of the pump NIVADIII is 5 L/min and the outflow tract pressure is 100 mmHg.According to the tests,the plasma free hemoglobin (FHB) content and the hematocrit (HCT) are measured after 0 s,0.5 s,1 s,1.5 s,...4 s.At the end of each experiment Normal Index of Hemolysis (NIH) of NIVADIII is calculated.The average of NIH is 0.0055 g/100L,almost identical with that obtained from the hemolytic prediction model.This method can be applied in the selection stage of a blood pump.

  8. Transient Stress- and Strain-Based Hemolysis Estimation in a Simplified Blood Pump

    OpenAIRE

    Pauli, L.; Nam, J.; Pasquali, M.; BEHR, M

    2013-01-01

    We compare two approaches to numerical estimation of mechanical hemolysis in a simplified blood pump model. The stress-based model relies on the instantaneous shear stress in the blood flow, whereas the strain-based model uses an additional tensor equation to relate distortion of red blood cells to a shear stress measure. We use the newly proposed least-squares finite element method (LSFEM) to prevent negative concentration fields and show a stable and volume preserving LSFEM for the tensor e...

  9. Calcification in Chronically-Implanted Blood Pumps: Experimental Results and Review of the Literature

    OpenAIRE

    Turner, Stephen A.; Bossart, Mattie I.; Milam, John D.; Fuqua, John M.; Igo, Stephen R.; McGee, Michael G.; Frazier, O. Howard

    1982-01-01

    Blood compatibility is a major objective in the development of long-term, implantable circulatory assist (left ventricular assist devices) and replacement (total artificial heart) devices. An important problem in experimental studies in animals has been the propensity for calcification to occur at the blood/material interface. Presented is a summary of our experience (27 studies) with blood pump calcification and a review of the current literature regarding this complication.

  10. Effect of parameter variations on the hemodynamic response under rotary blood pump assistance.

    Science.gov (United States)

    Lim, Einly; Dokos, Socrates; Salamonsen, Robert F; Rosenfeldt, Franklin L; Ayre, Peter J; Lovell, Nigel H

    2012-05-01

    Numerical models, able to simulate the response of the human cardiovascular system (CVS) in the presence of an implantable rotary blood pump (IRBP), have been widely used as a predictive tool to investigate the interaction between the CVS and the IRBP under various operating conditions. The present study investigates the effect of alterations in the model parameter values, that is, cardiac contractility, systemic vascular resistance, and total blood volume on the efficiency of rotary pump assistance, using an optimized dynamic heart-pump interaction model previously developed in our laboratory based on animal experimental measurements obtained from five canines. The effect of mean pump speed and the circulatory perturbations on left and right ventricular pressure volume loops, mean aortic pressure, mean cardiac output, pump assistance ratio, and pump flow pulsatility from both the greyhound experiments and model simulations are demonstrated. Furthermore, the applicability of some of the previously proposed control parameters, that is, pulsatility index (PI), gradient of PI with respect to pump speed, pump differential pressure, and aortic pressure are discussed based on our observations from experimental and simulation results. It was found that previously proposed control strategies were not able to perform well under highly varying circulatory conditions. Among these, control algorithms which rely on the left ventricular filling pressure appear to be the most robust as they emulate the Frank-Starling mechanism of the heart. PMID:22489771

  11. Interaction of an idealized cavopulmonary circulation with mechanical circulatory assist using an intravascular rotary blood pump.

    Science.gov (United States)

    Bhavsar, Sonya S; Moskowitz, William B; Throckmorton, Amy L

    2010-10-01

    This study evaluated the performance of an intravascular, percutaneously-inserted, axial flow blood pump in an idealized total cavopulmonary connection (TCPC) model of a Fontan physiology. This blood pump, intended for placement in the inferior vena cava (IVC), is designed to augment pressure and blood flow from the IVC to the pulmonary circulation. Three different computational models were examined: (i) an idealized TCPC without a pump; (ii) an idealized TCPC with an impeller pump; and (iii) an idealized TCPC with an impeller and diffuser pump. Computational fluid dynamics analyses of these models were performed to assess the hydraulic performance of each model under varying physiologic conditions. Pressure-flow characteristics, fluid streamlines, energy augmentation calculations, and blood damage analyses were evaluated. Numerical predictions indicate that the pump with an impeller and diffuser blade set produces pressure generations of 1 to 16 mm Hg for rotational speeds of 2000 to 6000 rpm and flow rates of 1 to 4 L/min. In contrast, for the same flow range, the model with the impeller only in the IVC demonstrated pressure generations of 1 to 9 mm Hg at rotational speeds of 10,000 to 12,000 rpm. Influence of blood viscosity was found to be insignificant at low rotational speeds with minimal performance deviation at higher rotational speeds. Results from the blood damage index analyses indicate a low probability for damage with maximum damage index levels less than 1% and maximum fluid residence times below 0.6 s. The numerical predictions further indicated successful energy augmentation of the TCPC with a pump in the IVC. These results support the continued design and development of this cavopulmonary assist device. PMID:20964699

  12. CENTRIFUGED BUFFY COAT SMEAR: AN ALTERNATIVE TO CONVENTIONAL PERIPHERAL BLOOD SMEAR FOR DIAGNOSIS OF MALARIA

    OpenAIRE

    Neelam; Praveen; Vaibhavi; Piyush

    2015-01-01

    INTRODUCTION: Malaria continues to be a global public health challenge with more than 200 million deaths annually, specially in the tropical and subtropical countries.(1) In India malaria is endemic throughout the country, problem accounting for 1-2 million cases and 1100 deaths per year.(1) The commonly employed method for diagnosis of malaria involves the microscopic examination of Romanowsky stained blood films.(2) For decades light microscopy of blood smears has be...

  13. Development of a portable bridge-to-decision blood pump.

    Science.gov (United States)

    Yamane, T; Kitamura, K

    2013-01-01

    We are developing an axial-flow pump with a cylindrical-impeller without airfoils. In the mock experiments of HA02 model a pressure of 13.3 kPa was obtained at a rotational speed of 12500 rpm and flow of 5L/min. The obtained pressure with HA02 was almost double than an airfoil-type impeller. The 2D analysis of hydrodynamic bearings for the pump revealed that a section with 3 or more arcs is stable with respect to angular position, and a minimum bearing gap of 100 µm can be attained at a design bearing gap of 150 µm and at a groove depth of 100 µm. PMID:24110291

  14. Validation of an axial flow blood pump: computational fluid dynamics results using particle image velocimetry.

    Science.gov (United States)

    Su, Boyang; Chua, Leok Poh; Wang, Xikun

    2012-04-01

    A magnetically suspended axial flow blood pump is studied experimentally in this article. The pump casing enclosed a three-blade straightener, a two-blade impeller shrouded by a permanent magnet-embedded cylinder, and a three-blade diffuser. The internal flow fields were simulated earlier using computational fluid dynamics (CFD), and the pump characteristic curves were determined. The simulation results showed that the internal flow field was basically streamlined, except the diffuser region. Particle image velocimetry (PIV) measurement of the 1:1 pump model was conducted to validate the CFD result. In order to ensure the optical access, an acrylic prototype was fabricated with the impeller driven by a servomotor instead, as the magnet is opaque. In addition to the transparent model, the blood analog fluid with the refractive index close to that of acrylic was used to avoid refraction. According to the CFD results, the axial flow blood pump could generate adequate pressure head at the rotating speed of 9500rpm and flow rate of 5L/min, and the same flow condition was applied during the PIV measurement. Through the comparisons, it was found that the experimental results were close to those obtained by CFD and had thus validated the CFD model, which could complement the limitation of the measurement in assessing the more detailed flow fields of the axial flow pump. PMID:22040356

  15. 日本2WTF—89型离心泵级间衬套改进%Improvement of the Internal Liner of Japanese 2WTF-89 Type Centrifugal Pumps

    Institute of Scientific and Technical Information of China (English)

    王茁; 张波

    2001-01-01

    通过对离心泵级间衬套的改进,有效地防止了泵的泄漏和零件的损坏,满足了生产工艺的使用要求。%The improvement of the internal liner of the 2WTF-89 type centrifugal pumps which prevented the pumps from leaking and the parts from damaging are introduced in this paper. It is satisfied for demand of production technology.

  16. Research on wear properties of centrifugal dredge pump based on liquid-solid two-phase fluid simulations

    Science.gov (United States)

    Peng, G. J.; Luo, Y. Y.; Wang, Z. W.

    2015-01-01

    The impeller and casing of dredge pump are worn by sediment in the flow. However, there are few studies about abrasion of the impeller and casing for normal pump operating conditions. This paper investigated the relationship between the wear rates on the surfaces of the impeller as well as casing and the sediment concentration, with the distribution of the wear rates for normal pump operating condition analyzed. An Eulerian-Lagrangian Computational Fluid Dynamics (CFD) procedure was used to simulate steady liquid-solid two-phase flow for various operating conditions. The Finnie model was then used to predict the abrasion. The results show that, the wear rate relative value of impeller and casing surface increase as the sediment concentration increases. The wear rate relative value of impeller and casing surface is larger when the pump is in low flow rate condition, and the value of casing surface is larger than that of the impeller. The wear rate relative value of pump is low when pump is in high efficiency condition. This paper shows the abrasion characteristics on the impeller and casing with sediment flow and provides reference data for predicting the abrasion conditions in the flow passage components for a dredge pump.

  17. Numerical Analysis of Blood Damage Potential of the HeartMate II and HeartWare HVAD Rotary Blood Pumps.

    Science.gov (United States)

    Thamsen, Bente; Blümel, Bastian; Schaller, Jens; Paschereit, Christian O; Affeld, Klaus; Goubergrits, Leonid; Kertzscher, Ulrich

    2015-08-01

    Implantable left ventricular assist devices (LVADs) became the therapy of choice in treating end-stage heart failure. Although survival improved substantially and is similar in currently clinically implanted LVADs HeartMate II (HM II) and HeartWare HVAD, complications related to blood trauma are frequently observed. The aim of this study was to compare these two pumps regarding their potential blood trauma employing computational fluid dynamics. High-resolution structured grids were generated for the pumps. Newtonian flow was calculated, solving Reynolds-averaged Navier-Stokes equations with a sliding mesh approach and a k-ω shear stress transport turbulence model for the operating point of 4.5 L/min and 80 mm Hg. The pumps were compared in terms of volumes subjected to certain viscous shear stress thresholds, below which no trauma was assumed (von Willebrand factor cleavage: 9 Pa, platelet activation: 50 Pa, and hemolysis: 150 Pa), and associated residence times. Additionally, a hemolysis index was calculated based on a Eulerian transport approach. Twenty-two percent of larger volumes above 9 Pa were observed in the HVAD; above 50 Pa and 150 Pa the differences between the two pumps were marginal. Residence times were higher in the HVAD for all thresholds. The hemolysis index was almost equal for the HM II and HVAD. Besides the gap regions in both pumps, the inlet regions of the rotor and diffuser blades have a high hemolysis production in the HM II, whereas in the HVAD, the volute tongue is an additional site for hemolysis production. Thus, in this study, the comparison of the HM II and the HVAD using numerical methods indicated an overall similar tendency to blood trauma in both pumps. However, influences of turbulent shear stresses were not considered and effects of the pivot bearing in the HM II were not taken into account. Further in vitro investigations are required. PMID:26234447

  18. Three-dimensional calculation of air-water two-phase flow in centrifugal pump impeller based on a bubbly flow model, 1

    International Nuclear Information System (INIS)

    To predict the behavior of air-water two-phase flows in a centrifugal pump impeller, a three-dimensional numerical method is proposed based on a bubbly flow model. If it is assumed that the mixtures are homogeneous bubbly flow containing fine bubbles compared with the characteristic length of the impeller channel, then the equations of motion of the mixtures are represented by those of liquid phase and its velocity is expressed as a potential for the quasi-harmonic equation. The equations are solved by use of the finite element method to obtain the velocities and pressures, and the equation of motion of an air bubble is integrated numerically on this flow field to obtain the void fraction. These calculations are repeated until the solutions converge. The results obtained show good agreement with experiments within the range of bubbly flow regime. (author)

  19. Emergency Abdominal Aortic Aneurysm Repair in a Patient with Failing Heart: Axillofemoral Bypass Using a Centrifugal Pump Combined with Levosimendan for Inotropic Support

    Directory of Open Access Journals (Sweden)

    Pavel Michalek

    2011-01-01

    Full Text Available We describe the case of an 83-year-old patient requiring repair of a large symptomatic abdominal aortic aneurysm (AAA. The patient was known to have coronary artery disease (CAD with symptoms and signs of significant myocardial dysfunction, left-heart failure, and severe aortic insufficiency. The procedure was performed with the help of both mechanical and pharmacological circulatory support. Distal perfusion was provided by an axillofemoral bypass with a centrifugal pump, with dobutamine and levosimendan administered as pharmacological inotropic support. The patient's hemodynamic status was monitored with continuous cardiac output monitoring and transesophageal echocardiography. No serious circulatory complications were recorded during the perioperative and postoperative periods. This paper suggests a potential novel approach to combined circulatory support in patients with heart failure, scheduled for open abdominal aortic aneurysm repair.

  20. 基于多块结构矢量裁剪的涡轮离心泵流场模拟%Simulation of Turbine Centrifugal Pump Flow Field Based on Multi Block Structure Vector Cutting

    Institute of Scientific and Technical Information of China (English)

    张明; 张铱鈖

    2015-01-01

    通过对涡轮离心泵的流场优化模拟,提高对涡轮离心泵的机械加工精度.传统方法使用多块结构化网格方法对涡轮离心泵流湍流度进行数值模拟,实现涡轮离心泵转子间隙流场分析,而涡轮离心泵转子的曲率随着转子的半开式旋转动态变化,影响流场分析精度.提出一种基于多块结构矢量裁剪的涡轮离心泵流场模拟方法.设计多块结构化网格,对涡轮离心泵流场分布进行控制设计,为了确保每一区域形成一个基于限定边约束三角网剖分,采用矢量裁剪方法,构建离心泵流场连点成面模型.仿真实验表明,采用该流场模拟方法能有效解决涡轮离心泵构造的层面拟合问题,提高了流场分析和模拟精度,实现涡轮离心泵流场模拟,指导机械加工,降低加工误差.%Through the optimization of flow field simulation of turbine centrifugal pump, improve the machining accuracy of turbine centrifugal pump. The use of unstructured grid method for multi block on the turbine centrifugal pump flow turbu-lence numerical simulation is carried out in the traditional method, the realization of the rotor gap flow field of turbine cen-trifugal pump analysis, while the turbine centrifugal pump rotor curvature with semi open rotary dynamic changes of the ro-tor, the precision analysis of effects of flow. A method is proposed to simulate the flow field of turbine centrifugal pump multi block structure vector based on cutting. Design of multi block structured grids, the flow field distribution of turbine centrifugal pump control design, in order to ensure that every region formed a limited boundary constrained triangulation based on vector, using cutting method, the construction of flow in centrifugal pump even point into a surface model. Simula-tion results show that, using the flow field can effectively solve the problem of turbine centrifugal pump level fitting struc-ture simulation methods, improve the flow field