scholarly journals Assessment of Cavitation Erosion in a Water-Jet Pump Based on the Erosive Power Method

Scanning ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ning Qiu ◽  
Han Zhu ◽  
Yun Long ◽  
Jinqing Zhong ◽  
Rongsheng Zhu ◽  
...  
Keyword(s):  
Cavitation Erosion ◽  
Water Jet ◽  
Power Method ◽  
Jet Pump ◽  
Tip Leakage ◽  
Long Duration ◽  
Simulation Based ◽  
Jet Pumps ◽  
Sst Turbulence Model ◽  
Simulation Error

Cavitation affects the performance of water-jet pumps. Cavitation erosion will appear on the surface of the blade under long-duration cavitation conditions. The cavitation evolution under specific working conditions was simulated and analyzed. The erosive power method based on the theory of macroscopic cavitation was used to predict cavitation erosion. The result shows that the head of the water-jet pump calculated using the DCM-SST turbulence model is 12.48 m. The simulation error of the rated head is 3.8%. The cavitation structure of tip leakage vortex was better captured. With the decrease of the net positive suction head, the position where the severe cavitation appears in the impeller domain gradually moves from the tip to the root. The erosion region obtained by the cavitation simulation based on the erosive power method is similar to the practical erosion profile in engineering. As the net positive suction head decreases, the erodible area becomes larger, and the erosion intensity increases.

CFD Investigation of Global Performance and Three Dimensional Flows in a Water-Jet Axial Flow Pump

2005 ◽  
Author(s):  
Hong Gao ◽  
Wanlai Lin ◽  
Fangming Ye
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Flow Fields ◽  
Water Jet ◽  
Jet Pump ◽  
Wall Functions ◽  
Global Performance ◽  
Jet Pumps ◽  
Axial Flow Pump ◽  
Radial Loading

The purpose of the present study is to investigate the global performance and three dimensional flow fields in a water-jet pump. TASCflow software is employed to simulate the rotator-stator coupling flow field. A standard k-ε turbulence model combined with standard wall functions is used. In order to investigate the effect of a rear stator on flow fields, the flows in two water-jet pumps with and without a rear stator are studied. The CFD predicted global performances are in good agreement with the experimental results. Then the flow fields, such as the pressure distribution on the blade surfaces, the axial and tangential velocities distribution, especially the radial loading distribution are investigated at different flow rates. In addition, the effect of a rear stator and different spacing between the rotor and the stator on the global performance and the flow fields of the water-jet pump are also investigated.

Numerical Assessment of Cavitation Erosion Risk in a Commercial Water-Jet Pump

2021 ◽  
Author(s):  
Mohammad Hossein Arabnejad ◽  
Urban Svennberg ◽  
Rickard E. Bensow
Keyword(s):  
Cavitation Erosion ◽  
Assessment Method ◽  
Water Jet ◽  
Numerical Results ◽  
Jet Pump ◽  
Erosion Risk ◽  
Hydraulic Machines ◽  
Numerical Assessment ◽  
Risk Areas ◽  
The Difference

Abstract In this paper, the risk of cavitation erosion is assessed in a commercial water-jet pump using a recently developed numerical erosion assessment method by Arabnejad et al. [1]. This assessment is performed for two flow conditions with different cavitation erosion risk according to the experimental paint tests and the high erosion risk areas identified by the method are compared with the experimental results. This comparison shows that the applied method is capable of both identifying the regions of high erosion risk and also capturing the difference between the cavitation erosion risk in the two studied conditions. The latter capability of the numerical assessment method, which has not been reported in the literature for other published methods, is one step forward toward the application of the method in the design process of hydraulic machines. Furthermore, the numerical results are analysed to explain the reasons for different erosion risk in the two conditions. This analysis reveals that this difference is mostly related to the stronger flow non-uniformities entering the rotor in the most erosive condition. Using the numerical results, one reason behind these stronger nonuniformities is identified to be the stronger bursting of vortices shed from the shaft in the most erosive condition.

Performance Prediction of Cavitating Water-Jet Propulsors Using a Viscous/Inviscid Interactive Method

2008 ◽  
Author(s):  
Hong Sun ◽  
Spyros A. Kinnas
Keyword(s):  
Viscous Flow ◽  
Performance Prediction ◽  
Water Jet ◽  
Interaction Method ◽  
Jet Pump ◽  
Interactive Method ◽  
Sheet Cavitation ◽  
Jet Pumps

The authors present a viscous/inviscid interaction method to predict the viscous flow inside water-jet pumps, including the effects of sheet cavitation on the rotor and /or stator blades. The circumferentially averaged interaction between the rotor and the stator is accounted for in an iterative manner. The method is applied in the case of an actual water-jet pump and comparisons of the predicted and the measured rotor torque are presented.

scholarly journals Investigation of Turbulent Tip Leakage Vortex in an Axial Water Jet Pump With Large Eddy Simulation

2012 ◽  
Author(s):  
Chunill Hah
Keyword(s):  
Flow Simulation ◽  
Water Jet ◽  
Tip Clearance ◽  
Jet Pump ◽  
Tip Leakage Vortex ◽  
Tip Clearance Flow ◽  
Cavitation Inception ◽  
Tip Leakage ◽  
Eddy Simulation ◽  
Clearance Flow

Detailed steady and unsteady numerical studies were performed to investigate tip clearance flow in an axial water jet pump. The primary objective is to understand physics of unsteady tip clearance flow, unsteady tip leakage vortex, and cavitation inception in an axial water jet pump. Steady pressure field and resulting steady tip leakage vortex from a steady flow analysis do not seem to explain measured cavitation inception correctly. The measured flow field near the tip is unsteady and measured cavitation inception is highly transient. Flow visualization with cavitation bubbles shows that the leakage vortex is oscillating significantly and many intermittent vortex ropes are present between the suction side of the blade and the tip leakage core vortex. Although the flow field is highly transient, the overall flow structure is stable and a characteristic frequency seems to exist. To capture relevant flow physics as much as possible, a Reynolds-averaged Navier-Stokes (RANS) calculation and a Large Eddy Simulation (LES) were applied for the current investigation. The present study reveals that several vortices from the tip leakage vortex system cross the tip gap of the adjacent blade periodically. Sudden changes in local pressure field inside tip gap due to these vortices create vortex ropes. The instantaneous pressure filed inside the tip gap is drastically different from that of the steady flow simulation. Unsteady flow simulation which can calculate unsteady vortex motion is necessary to calculate cavitation inception accurately even at design flow condition in such a water jet pump.

Optimum Design of Water Jet Pumps

1969 ◽  
Vol 91 (1) ◽  
pp. 62-68 ◽  
Author(s):  
J. R. Cairns ◽  
T. Y. Na
Keyword(s):  
Optimum Design ◽  
Water Jet ◽  
Jet Pump ◽  
Analytical Work ◽  
Jet Pumps ◽  
Extensive Program

A summary of an extensive program of experimental and analytical work leading to a procedure for obtaining optimized performance of water jet-pump systems is presented. The procedure is extended to include systems involving n, series-staged ejector components operating in an optimal manner as a complete pump, pipeline, ejector unit. The theoretical, limiting performance of ejectors is established and several examples involving different design situations are shown.

CFD Calculation of the Flow Through a Water-Jet Pump

2001 ◽  
Author(s):  
Peixin Hu ◽  
◽  
M Zangeneh ◽  
Keyword(s):  
Water Jet ◽  
Jet Pump ◽  
Flow Through

Miniaturization of injection abrasive water jet machining process

2006 ◽  
Vol 220 (11) ◽  
pp. 1697-1705 ◽  
Author(s):  
H Orbanic ◽  
B Jurisevic ◽  
D Kramar ◽  
M Grah ◽  
M Junkar
Keyword(s):  
Water Jet ◽  
Heat Sinks ◽  
Machining Process ◽  
Process Efficiency ◽  
Abrasive Water Jet ◽  
Element Analysis ◽  
Abrasive Particles ◽  
Cutting Head ◽  
Simulation Based ◽  
Awj Cutting

This contribution presents the possibilities of applying abrasive water jet (AWJ) technology for multi-material micromanufacture. The working principles of injection and suspension AWJ systems are presented. Characteristics of this technology, such as the ability to machine virtually any kind of material and the absence of a relevant heat-affected zone, are given, especially those from which the production of microcomponents can benefit. A few attempts to miniaturize the AWJ machining process are described in the state-of-the-art preview. In order to develop and improve the AWJ as a microtool, a numerical simulation based on the finite element analysis is introduced to evaluate the effect of the size abrasive particles and the process efficiency of microsized AWJ. An ongoing project in which an improved mini AWJ cutting head is being developed, is presented. Finally, the possible fields of application are given, including a case study on the machining of miniaturized heat sinks.

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