Prediction of Sheet Cavitation in a Centrifugal Pump Impeller With the Three-Dimensional Potential-Flow Model

2005 ◽  
Author(s):  
R. J. H. Dijkers ◽  
B. Fumex ◽  
J. G. H. Op de Woerd ◽  
N. P. Kruyt ◽  
H. W. M. Hoeijmakers
Keyword(s):  
Centrifugal Pump ◽  
Potential Flow ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Limiting Factors ◽  
Centrifugal Pumps ◽  
Pump Impeller ◽  
Flow Equations ◽  
Sheet Cavitation ◽  
Centrifugal Pump Impeller

The occurrence of cavitation is one of the main limiting factors in the operation and design of centrifugal pumps. In this paper a model for the prediction of sheet cavitation is described. This model has been implemented in a three-dimensional finite-element package, employing the potential-flow approximation of the governing flow equations. At the interface between vapor and liquid, pressure equilibrium is required. The closure region of the cavity is modeled as the collapse of a bubble, whose motion is described by the Rayleigh-Plesset equation. The effect of displacement of the flow due to presence of the sheet cavity is incorporated by the transpiration technique. This is a linearised approach which is well-known from techniques for coupling inviscid-flow methods to boundary-layer methods. The model gives the location of the sheet cavity (if present); its length is thus also predicted. The model has been validated by comparing sheet cavitation at the blades of a centrifugal pump impeller, obtained from CFD-computations and from visual observations in a model test.

Comparison of Inlet Curved Disk Arrangements for Suppression of Recirculation in Centrifugal Pump Impellers

2016 ◽  
Author(s):  
Munther Y. Hermez ◽  
Badih A. Jawad ◽  
Liping Liu ◽  
Vernon Fernandez ◽  
Kingman Yee ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
Operating Cost ◽  
Three Dimensional ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Pump Impeller ◽  
Flow Rates ◽  
Flow Recirculation ◽  
Flow Field Characteristics

The present work aims to numerically study the inlet flow recirculation and modified impeller interaction in a centrifugal pump. An optimization of modified shrouded impeller with curved disk arrangement to suppress the unsteady flow recirculation is pursued. This modification will enhance the impeller characteristics with a wider operation range at both low and high flow rates in a high speed centrifugal pump type. The unstable flow in the centrifugal pumps is a common problem that leads to damage in the pump’s internal parts, consequently increases the operating cost. At certain flow rates, generally below the Best Efficiency Point (BEP), all centrifugal pumps are subject to internal recirculation occurs at the suction and discharge areas of the impeller. For decades, experimental work has been done to investigate the complex three-dimensional flow within centrifugal pumps impellers, before computational work gains momentum due to advancement of computing power and improved numerical codes. In this study the impeller with a curved disk arrangement has been investigated by using a three-dimensional Navier-Stokes code with a standard k-ε turbulence model. The purpose is to evaluate and select the optimum impeller modification that would increase the pump suction flow rate range. Three-dimensional numerical Computational Fluid Dynamics (CFD) tools are used to simulate flow field characteristics inside the centrifugal pump and provide critical hydraulic design information. In the present work, ANSYS v.16.1 Fluent solver is used to analyze the pressure and velocity distributions inside impeller suction and discharge passages. The ultimate goal of this study is to manufacture and validate the most optimized and efficient centrifugal pump impeller with a curved disk. The best case curve identifies the highest increase of total pressure difference by 22.1%, and highest efficiency by 92.3% at low flowrates.

Design and Analysis of Airfoil-Shaped Impeller Blades of Centrifugal Pump

2016 ◽  
Vol 852 ◽  
pp. 539-544
Author(s):  
Parth Shah ◽  
M. Ashwin Ganesh ◽  
Thundil Kuruppa Raj
Keyword(s):  
Centrifugal Pump ◽  
Transport Model ◽  
Turbulence Models ◽  
Suction Side ◽  
3D Analysis ◽  
Centrifugal Pumps ◽  
Pump Impeller ◽  
Outlet Pressure ◽  
Shear Stress Transport Model ◽  
Centrifugal Pump Impeller

This paper deals with a comparative study of the outlet pressure-energy between a conventional and normal blade impeller and an airfoil-shaped blade impeller of a centrifugal pump. Although the volute casing is an important component along with an impeller [1], the present comparative analysis makes the volute casing redundant to the study, hence neglected. All centrifugal pumps are usually designed and manufactured using backward swept blades with equal camber on the top and bottom sides. An increased camber on the top side is an ideal trait for a lift generating airfoil. The purpose is to implement the principle of lift generation of airfoil for centrifugal pumps. As a result, a local suction side and pressure side can be visualized using CFX-post processor. The 3D analysis of such a centrifugal pump impeller is designed in SOLIDWORKS® and analyzed using ANSYS® CFX. The SST (Menter’s Shear Stress Transport) model is used as it combines both the k-ω and k-ε turbulence models.

Three-Dimensional Calculation of Air-Water Two-Phase Flow in Centrifugal Pump Impeller Based on a Bubbly Flow Model

1993 ◽  
Vol 115 (4) ◽  
pp. 766-771 ◽  
Author(s):  
Kiyoshi Minemura ◽  
Tomomi Uchiyama
Keyword(s):  
Centrifugal Pump ◽  
Flow Model ◽  
Liquid Velocity ◽  
Bubbly Flow ◽  
Three Dimensional ◽  
Equation Of Motion ◽  
Two Phase ◽  
Pump Impeller ◽  
Harmonic Equation ◽  
Centrifugal Pump Impeller

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.

Performance Characteristics of a Centrifugal Pump Impeller With Running Tip Clearance Pumping Solid-Liquid Mixtures

2001 ◽  
Vol 123 (3) ◽  
pp. 532-538 ◽  
Author(s):  
Tahsin Engin ◽  
Mesut Gur
Keyword(s):  
Centrifugal Pump ◽  
Liquid Mixtures ◽  
Reduction Factor ◽  
Tip Clearance ◽  
Performance Characteristics ◽  
Solid Concentration ◽  
Centrifugal Pumps ◽  
Pump Impeller ◽  
Solid Liquid ◽  
Centrifugal Pump Impeller

This paper presents extensive results on the performance of an unshrouded centrifugal pump impeller handling solid-liquid mixtures. The effect of the clearance between the impeller tip and the casing and of the solid concentration, density and mean diameter on the pump performance characteristics is investigated. The results are discussed and utilized, together with data available in the literature, to establish a correlation allowing the prediction of the head reduction factor for shrouded/unshrouded impeller centrifugal pumps handling solid-liquid mixtures. The predictions made with the proposed correlation show a better agreement with experimental results than previous ones.

scholarly journals Pressure Fluctuation in a Vaned Diffuser Downstream from a Centrifugal Pump Impeller

2003 ◽  
Vol 9 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Akinori Furukawa ◽  
Hisasada Takahara ◽  
Takahiro Nakagawa ◽  
Yusuke Ono
Keyword(s):  
Centrifugal Pump ◽  
Static Pressure ◽  
Pressure Fluctuations ◽  
Flow Analysis ◽  
Inviscid Flow ◽  
Blade Surface ◽  
Pump Impeller ◽  
Vaned Diffuser ◽  
Singularity Method ◽  
Centrifugal Pump Impeller

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.

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