Comparison of Transport Equation-Based Cavitation Models and Application to Industrial Pumps with Inducers

2021 ◽  
Author(s):  
Enver Karakas ◽  
Nehir Tokgoz ◽  
Hiroyoshi Watanabe ◽  
Matteo Aureli ◽  
Cahit Evrensel
Keyword(s):  
Transport Equation ◽  
Centrifugal Pump ◽  
Experimental Results ◽  
Vaporization Rate ◽  
Centrifugal Pumps ◽  
Cavitation Model ◽  
Cavitation Performance ◽  
High Dependency ◽  
The Impact ◽  
Empirical Constants

Abstract This paper investigates and compares four commonly used flow transport equation-based cavitation models and their applicability to predict the cavitation performance and bubble dynamics of an industrial centrifugal pump with a helical inducer. The main purpose of this study is to identify the most appropriate cavitation model and the associated empirical constants for calculating the cavitation performance of centrifugal pumps with inducers. Each cavitation model is reviewed in detail and the uniqueness of each model is outlined. These cavitation models are incorporated in a computational fluid dynamics code to study the vaporization and condensation transport rate of the fluid. Experimental tests are conducted on the pump to determine the true cavitation performance in terms of Net Positive Suction Head (NPSH). Experimental results are compared to simulation results for different cavitation models to validate accuracy and assumptions of each model, along with the empirical constants. Lastly, bubble formation, cavitation inception, and bubble growth predicted by each cavitation model are compared with the experimental results. A sensitivity analysis is conducted in order to determine the impact of each set of empirical constants to the condensation and the vaporization rate in the centrifugal pump. Results show that two of the cavitation models exhibit high dependency on the empirical constants in terms of change in vaporization rate. Modifications to empirical constants for two of the four cavitation models are suggested to obtain agreement with the experimentally observed cavitation behavior and better predict NPSH performance for the industrial pump studied.

scholarly journals Influence of wall roughness on cavitation performance of centrifugal pump

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Internal Flow ◽  
Wall Roughness ◽  
Blade Surface ◽  
Centrifugal Pumps ◽  
Three Dimensional Model ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Critical Cavitation

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

The Rotating Cavitation Performance of a Centrifugal Pump with a Splitter-Bladed Inducer under Different Rotational Speed

2015 ◽  
Vol 32 (3) ◽  
Author(s):  
XiaoMei Guo ◽  
ZuChao Zhu ◽  
BaoLing Cui ◽  
Yi Li
Keyword(s):  
Centrifugal Pump ◽  
Rotational Speed ◽  
High Speed ◽  
Internal Flow ◽  
Centrifugal Pumps ◽  
Cavitation Flow ◽  
Operation Condition ◽  
Cavitation Performance ◽  
Cavitation Behavior ◽  
Suction Performance

AbstractDesigning inducer is one of the effective ways to improve the suction performance of high-speed centrifugal pumps. The operation condition including rotational speeds can affect the internal flow and external performance of high-speed centrifugal pumps with an inducer. In order to clarify the rotating cavitation performance of a centrifugal pump with a splitter-bladed inducer under different rotational speed, a centrifugal pump with a splitter-bladed inducer is investigated in the work. By using Rayleigh–Plesset equations and Mixture model, the cavitation flow of centrifugal pump is numerically simulated, as well as the external performance experimental test is carried out. It is found that the cavitation area increases with the rotational speeds. The location of the passage where cavitation is easy to appear is explored. Asymmetric cavitation behavior is observed. That, the trail of the inducer is easy to take cavitation when the rotational speed is increased to a degree, is also observed. The trend of

Thermodynamic Effect and Cavitation Performance of a Cavitating Centrifugal Pump

2011 ◽  
Author(s):  
Teiichi Tanaka
Keyword(s):  
Centrifugal Pump ◽  
Liquid Nitrogen ◽  
Cold Water ◽  
Experimental Results ◽  
Flow Coefficient ◽  
Test Setup ◽  
Cavitation Performance ◽  
Thermodynamic Effect ◽  
Delivery Pressure ◽  
Temperature Depression

The thermodynamic effect which affects the cavitation performance of a cavitating centrifugal pump was investigated experimentally using liquid nitrogen. To measure the pump cavitation performance, a test setup which could carry out experiments using both liquid nitrogen and cold water was constructed. The test setup consisted of a suction tank, a test pump, a mass flow meter, a ball valve and pipes. Vacuum-insulated pipes were used. The test pump was a centrifugal type magnetic pump, and two impellers, which differed in cavitation performance, were used in experiments. Cavitation performance using liquid nitrogen or cold water could be obtained from the measurement of the pump suction and delivery pressure, the pump suction and delivery temperature, and the discharge flow rate. And an improvement in pump cavitation performance could be seen when comparing the experimental results from using liquid nitrogen with those from using cold water. The experimental results indicated that cavitation performance using liquid nitrogen was better than that using cold water. This improvement in cavitation performance was thought to be due to the thermodynamic effect of cavitation. And the estimated temperature depression due to the thermodynamic effect decreased with a decreasing flow coefficient. Moreover, it was shown that the estimated temperature depression due to the thermodynamic effect on the low cavitation performance impeller was larger than that on the high cavitation performance impeller at the same flow coefficient.

scholarly journals Perancangan Knowledge Management Perawatan Dan Perbaikan Mesin Pompa Sentrifugal Menggunakan Metode Case Based Reasoning

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Fathoni ◽  
Syahrizal Dwi
Keyword(s):  
Knowledge Management ◽  
Production Process ◽  
Centrifugal Pump ◽  
Explicit Knowledge ◽  
Retrieval Algorithm ◽  
Case Based Reasoning ◽  
Centrifugal Pumps ◽  
Analysis And Design ◽  
The Impact ◽  
Case Based

ABSTRACTThe utilization and existence of centrifugal machine pumps in the industrial world is very important to assist the production process, at least almost 75% of industries use this type of machine pump. As an operational tool in the industry, centrifugal pumps must be able to be used and maintained properly because the damage to the pumping machine causes the operational or production process to be not maximal even can lead to cessation of the production process, and the impact on financial losses are not small. This study aims to create a knowledge management design to assist in the manufacture of software so that ultimately can facilitate the users (technicians) centrifugal pump machine do maintenance and repair the machine. To achieve the purpose of the research the researcher uses the stages of research consisting of three stages, namely: Phase 1. Preparation and Identification of knowledge; Phase 2. Analysis and Design of Knowledge Management and Phase 3. Design of Knowledge Management Prototype. Meanwhile, to manage the knowledge and explicit knowledge of the researcher using Case-Based Reasoning (CBR) method by using Nearest Neighbor Retrieval algorithm to find the best solution in maintaining and repairing centrifugal pump machine by calculating the proximity between new technical constraints and the old technical obstacle already in the database. This study resulted in a knowledge management design consisting of functional requirements and flow and software algorithms to assist application developers in the creation of knowledge management software interfaces to maintain and repair centrifugal pump machines.Keywords: Centrifugal Pump Machine, Knowledge Management, Case-Based Reasoning

Study on radial force characteristics of double-suction centrifugal pumps with different impeller arrangements under cavitation condition

2020 ◽  
pp. 095765092092682
Author(s):  
Yu Song ◽  
Honggang Fan ◽  
Zhenwei Huang
Keyword(s):  
Strong Influence ◽  
Radial Force ◽  
Force Distribution ◽  
Centrifugal Pumps ◽  
Cavitation Model ◽  
Cavitation Phenomenon ◽  
Cavitation Performance ◽  
Critical Cavitation ◽  
Force Characteristics ◽  
Different Parts

Cavitation phenomenon is inevitable in pumps with strong transient characteristics. Due to the presence of vapors, the pressure distribution in the impeller changes greatly, resulting in a different radial force distribution from that in non-cavitation condition. In the present article, the cavitation performance of double-suction pumps with different impeller–vane arrangements is studied using the renormalization group k–& turbulence model and the Zwart–Gerber–Belamri cavitation model. The radial force on the two impellers and the whole pump are calculated and compared under critical cavitation conditions. The radial force on different parts of impellers is investigated in detail. A strong influence of the radial force on the blades is detected for different impeller–vane arrangements. Then, the flow characters are analyzed in the mid-span of volute. The results show that axial flows are detected in volute near the outlet of the impellers, which is the main cause of the “two-impeller-interaction”.

Numerical Simulation of Cavitation Phenomena in a Centrifugal Pump

2009 ◽  
Author(s):  
Freddy Jeanty ◽  
Jesu´s De Andrade ◽  
Miguel Asuaje ◽  
Frank Kenyery ◽  
Auristela Va´squez ◽  
...  
Keyword(s):  
Experimental Data ◽  
Centrifugal Pump ◽  
Cfd Simulation ◽  
Common Phenomenon ◽  
Performance Parameters ◽  
Centrifugal Pumps ◽  
Cavitation Model ◽  
Cfd Simulations ◽  
Global Performance ◽  
Good Agreement

Cavitation is a common phenomenon that appears during the operation of the hydraulic turbomachines reducing performance and life of Centrifugal pumps. The main goal of this work is primarily a CFD-simulation of the whole Centrifugal Pump-Turbine including the suction cone, impeller, diffuser blades and volute, in order to characterize and evaluate its performance under cavitation conditions. The CFD simulations results were compared with experimental data under cavitation and non-cavitation conditions. A good agreement has been obtained under non-cavitation conditions for global performance parameters. After the implementation of the Rayleigh Plesset cavitation model, the required Net Positive Suction Head (NPSHr) has been predicted from CFD simulations. Finally, a full cavitation test can be reproduced for a Hydraulic Turbomachine to avoid this dangerous phenomenon.

Effects of Different Turbulence Models on Three-Dimensional Unsteady Cavitating Flows in the Centrifugal Pump and Performance Prediction

2019 ◽  
Vol 20 (3-4) ◽  
pp. 487-509 ◽  
Author(s):  
Ahmed Ramadhan Al-Obaidi
Keyword(s):  
Centrifugal Pump ◽  
Turbulence Model ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Experimental Results ◽  
Centrifugal Pumps ◽  
Operation Condition ◽  
Sst Model ◽  
And Performance ◽  
Turbulent Models

AbstractIn centrifugal pumps, it is important to select appropriate turbulence model for the numerical simulation in order to obtain reliable and accurate results. In this work, ten turbulence models in 3-D transient simulation for the centrifugal pump are chosen and compared. The pump performance is validated with experimental results. The numerical results reveal that the SST turbulence model was closer to the experimental results in predicting head. In addition, the pressure variation trend for the ten models is very similar which increases and then decreases from the inlet to outlet of the pump along the streamline. The SST k-ω model predicts the performance of the pump was more accurately than other turbulent models. Furthermore, the results also found that the error is the least at design operation condition 300(l/min), which is around 1.98 % for the SST model and 2.14 % and 2.38 % for the LES and transition omega model. Within 7.61 %, the errors at higher flow rate 350(l/min) for SST. The error for SST model is smaller as compared to different turbulent models. For the Realizable k-ɛ model, the errors fluctuate were more high than other models.

Modeling Viscous Oil Cavitating Flow in a Centrifugal Pump

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Wen-Guang Li
Keyword(s):  
Centrifugal Pump ◽  
Volume Ratio ◽  
Cavitating Flow ◽  
Liquid Volume ◽  
Cavitation Model ◽  
Gas Concentration ◽  
Noncondensable Gas ◽  
Cavitation Performance ◽  
Pump Head ◽  
Cfd Method

Properly modeling cavitating flow in a centrifugal pump is a very important issue for prediction of cavitation performance in pump hydraulic design optimization and application. As a first trial, the issue is explored by using computational fluid dynamics (CFD) method plus the full cavitation model herein. To secure a smoothed head-net positive suction head available (NPSHa) curve, several critical techniques are adopted. The cavitation model is validated against the experimental data in literature. The predicted net positive suction head required (NPSHr) correction factor for viscosity oils is compared with the existing measured data and empirical correlation curve, and the factor is correlated to impeller Reynolds number quantitatively. A useful relation between the pump head coefficient and vapor plus noncondensable gas-to-liquid volume ratio in the impeller is obtained. Vapor and noncondensable gas concentration profiles are illustrated in the impeller, and a “pseudocavitation” effect is confirmed as NPSHa is reduced. The effects of exit blade angle on NPSHr are presented, and the contributions of liquid viscosity and noncondensable gas concentration to the increase of NPSHr at a higher viscosity are identified.

scholarly journals Prediction of Abrasive and Impact Wear Due to Multi-Shaped Particles in a Centrifugal Pump via CFD-DEM Coupling Method

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2391
Author(s):  
Cheng Tang ◽  
You-Chao Yang ◽  
Peng-Zhan Liu ◽  
Youn-Jea Kim
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Centrifugal Pump ◽  
Coupling Method ◽  
Particle Model ◽  
Equivalent Diameter ◽  
Impact Wear ◽  
Centrifugal Pumps ◽  
Wear Model ◽  
The Impact

Since solid particles suspended in the fluid can cause wear in centrifugal pumps, intensive attention has been focused on the numerical prediction for the wear of flow parts in centrifugal pumps. However, most numerical studies have focused on only one wear model and a sphere particle model. The impact of particle shape on the wear of flow parts in centrifugal pumps is under-studied, particularly considering abrasive and impact wear simultaneously. In this work, the Computational Fluid Dynamics (CFD)-Discrete Element Method (DEM) coupling method with an abrasive and impact wear prediction model was adopted to study the wear characteristics of a centrifugal pump. Moreover, four regular polyhedron particles and a sphere particle with the same equivalent diameter but different sphericity were mainly analyzed. The results demonstrate that more particles move closer to the blade pressure side in the impeller passage, and particles tend to cluster in specific areas within the volute as sphericity increases. The volute suffers the principal wear erosion no matter what the shapes of particles and wear model are. Both the impact and abrasive wear within the impeller occur primarily on the blade leading edge. The pump’s overall impact wear rate decreases first and then increases with particle sphericity rising, while the pump’s overall abrasive wear rate grows steadily.

scholarly journals Deteksi kavitasi menggunakan linear discriminant analysis pada pompa sentrifugal

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Berli Paripurna Kamiel ◽  
Yusuf Ahmad ◽  
Krisdiyanto Krisdiyanto
Keyword(s):  
Machine Learning ◽  
Discriminant Analysis ◽  
Linear Discriminant Analysis ◽  
Centrifugal Pump ◽  
Shape Factor ◽  
Vibration Signal ◽  
Large Contribution ◽  
Centrifugal Pumps ◽  
Linear Discriminant ◽  
The Impact

Cavitation is a phenomenon that often occurs in the centrifugal pumps. The impact of cavitation is a decrease in pump performance which will affect the ongoing production process in the industries. It is important to have a method to detect the phenomenon of cavitation early. The vibration signal is a parameter that is often used in detecting cavitation or other faulty components. One of the methods is based on the pattern recognition i.e. machine learning. Linear Discriminant Analysis (LDA) is a machine learning algorithm that has the advantage of reducing the parameters used into low dimensions without reducing the accuracy of their classification. The study proposes LDA to classify normal conditions, initial cavitation, intermediate cavitation and severe cavitation. The recording of the vibration signal is taken using the an accelerometer mounted on the inlet of the centrifugal pump. The vibration signal is then extracted using 10 statistic parameters of time domain as the LDA feature selection, namely mean, RMS, standard deviation, kurtosis, skewness, crest factor, clearance factor, shape factor, variance and peak value. The results shows that the LDA classifier can detect and classify cavitation conditions with an accuracy rate of 98.8% on training and 99.6% on testing. The shape factor, kurtosis, skewness and RMS parameters are a combination of parameters that have a large contribution to the classifier to detect and classify cavitation conditions.Keywords: Linear Discriminant Analysis (LDA), cavitation, centrifugal pump, statistical parameter

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