The Experts below are selected from a list of 3294 Experts worldwide ranked by ideXlab platform
Desheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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a study on tip leakage vortex dynamics and cavitation in Axial Flow Pump
Fluid Dynamics Research, 2017Co-Authors: Lei Shi, Desheng Zhang, Weidong Shi, Yongxin Jin, B P M Van EschAbstract:The tip leakage Flows and related cavitation in the tip region of an Axial-Flow Pump were investigated in detail using the numerical and experimental methods. The numerical results of the Pump model performance were in good agreement with experimental data. The Flow structures in the tip clearance were clarified clearly with detailed data involving the Axial velocity and turbulent kinetic energy. When depicting the feature of vortex core, the advanced vortex identification method λ 2-criterion was used. Simultaneously, the minimum tension criterion was also applied to predict the cavitation inception for different Flow rates and it is consistent with the distributions of vorticity and pressure in the vortex core. The roll-up process of TLV is highly three-dimensional and the entrainment would follow different paths. Then, both the numerical and experimental approaches show the cavitation patterns for different cavitation conditions, and it also finds that slight cavitation would promote the development of tip leakage vortex (TLV) while the TLV seems to be eliminated for a low cavitation number, especially before a specific location of blade tip due to the blade loading change induced by cavitation possibly.
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Numerical simulation and optimization of solid-liquid two-phase Flow in a back-swept Axial-Flow Pump
Thermal Science, 2017Co-Authors: Desheng Zhang, Weidong Shi, Qiang Pan, Rui-jie Zhang, Xing JinAbstract:The simulation study is proposed to analyze the wear property of the Axial Flow Pump using the sewage as medium. Different Axial Flow Pumps are designed with different back-swept angles, of which are 40?, 65?, and 90?. Numerical simulation results showed the relationship between solid volume fraction and back-swept angle on the pressure/suction surface, as well as the particle diameter. To validate the correctness of numerical investigation, the result of the 65? backswept blade model was compared with a sludge Axial Flow Pump in sewage treatment plant, which showed fair agreement with the simulated results.
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numerical and experimental investigation of tip leakage vortex trajectory and dynamics in an Axial Flow Pump
Computers & Fluids, 2015Co-Authors: Desheng Zhang, Weidong Shi, B P M Van Esch, Lei Shi, Michel DubuissonAbstract:Abstract Tip leakage vortex (TLV) in an Axial Flow Pump was simulated by using the shear-stress transport (SST) k – ω turbulence model with a refined high-quality structured grid at different Flow rate conditions. The TLV trajectories were obtained by using the swirling strength method corresponding to the cross-sections of streamlines of the TLV. High-speed photography experiments were conducted to observe the TLV trajectory based on cavitation tracing bubbles in an Axial Flow Pump with a transparent casing. The TLV trajectories predicted by the SST k – ω turbulence model agreed well with the visualization results. The numerical and experimental results show that the starting point of the TLV is near the leading edge at part-load Flow rate condition ( Q / Q BEP = 0.85 ), and it moves towards the trailing edge to approximately 20% blade chord at the design Flow rate condition ( Q / Q BEP = 1.0 ). At large Flow rate conditions ( Q / Q BEP = 1.2 ), the starting point of the TLV shifts to about 40% blade chord, and the relative angle between the TLV trajectory and the blade chord is gradually reduced with the increased Flow rate. Detailed statistics of the fluid dynamics of the end-wall shear layer and the TLV at design and off-design conditions were discussed based on the numerical results. The shear layer and jetting Flow in the tip gap are highly affected by the pressure difference between the pressure side (PS) and suction side (SS). It was also found that the distributions of static pressure, turbulent kinetic energy (TKE) and vorticity inside the TLV core are associated with the TLV structure which is affected by blade loading and operation conditions of the Axial Flow Pump.
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Effects on the performance and Flow field of the Axial Flow Pump hydraulic components with Fluid-Solid Interaction
2013Co-Authors: Desheng Zhang, Yang Liu, Yanlei Guo, Peipei Shao, Shi WeidongAbstract:The two-way calculation of fluid field and the combined solution of structural transient dynamic analysis of Axial Flow Pump are carried out based on elastomer structural dynamics equation and Navier-Stokes equation and RNG k-e turbulence model, the effect of the Fluid-Solid Interaction (FSI) on the head and efficiency of Axial Flow Pump, and the Flow field and the Axial force were analysed. The Axial Pump blade dynamic stress characteristics were investigated. The blade displacement and deformation and stress distribution were predicted. The head and efficiency of Axial Flow Pump considering FSI effect were analysed. Numerical results show that the maximum displacement of the Axial Flow Pump impeller blade with FSI effect occurs in the blade inlet at the rim, but the displacement of the blade root is smaller; the impeller blade root close to the hub exists significant stress concentration phenomenon; the stress and deformation of blade gradually decreases with the Flow rate increasing; the head and efficiency with FSI has declined comparing with not considering FSI, but the decline is small without considering FSI. .
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study on tip leakage vortex in an Axial Flow Pump based on modified shear stress transport k ω turbulence model
Thermal Science, 2013Co-Authors: Desheng Zhang, Weidong Shi, Dazhi Pan, Peipei ShaoAbstract:The tip leakage vortex structure and trajectory in an Axial Flow Pump were investigated numerically and experimentally based on the modified shear stress transport k-ω turbulence model. Numerical results were compared with the experimental leakage vortex trajectories, and a good agreement was presented. The detailed trajectories of tip leakage vortex show that the starting point of tip leakage vortex occurs near the leading edge at small Flow rate, and it moves from leading edge to about 30% chord length at design Flow rate. At larger Flow rate condition, the starting point of tip leakage vortex shifts to the middle of chord.
Zhang Qian - One of the best experts on this subject based on the ideXlab platform.
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Distribution of unsteady pressure in volute type Axial Flow Pump
Journal of Vibroengineering, 2018Co-Authors: Cao Weidong, Yao Lingjun, Zhang QianAbstract:In order to study the distribution of unsteady pressure in volute type Axial Flow Pump, the k-e turbulence model was applied, and ANSYS CFX was provided for numerical simulation calculation. Experiments of external characteristics and pressure fluctuation have been done to verify the results of numerical simulation. The results show that under the design operating condition, the main fluctuation frequencies in the volute, at the inlet and outlet of the impeller are the blade passing frequency. The amplitudes of fluctuation at the inlet of the impeller decrease gradually from the rim to the hub, while those at the export decrease firstly and then increase, the amplitudes at the tongue are much higher than that at other sections of the volute. Under the off-design operating conditions, the main fluctuation frequency at the inlet and outlet of the impeller is still the blade passing frequency, while that at the tongue is between the twice shaft frequency and the blade passing frequency, fluctuation amplitudes are both larger than those under the design operating condition. Under the design operating condition, the radial force on the impeller is the minimum, however, the Axial force increases with the increase of Flow rate. The distributions of unsteady pressure in volute type Axial Flow Pump are different with general centrifugal or Axial Flow Pump.
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Distribution of unsteady pressure in volute type Axial Flow Pump
'JVE International Ltd.', 2018Co-Authors: Cao Weidong, Yao Lingjun, Zhang QianAbstract:In order to study the distribution of unsteady pressure in volute type Axial Flow Pump, the k-ε turbulence model was applied, and ANSYS CFX was provided for numerical simulation calculation. Experiments of external characteristics and pressure fluctuation have been done to verify the results of numerical simulation. The results show that under the design operating condition, the main fluctuation frequencies in the volute, at the inlet and outlet of the impeller are the blade passing frequency. The amplitudes of fluctuation at the inlet of the impeller decrease gradually from the rim to the hub, while those at the export decrease firstly and then increase, the amplitudes at the tongue are much higher than that at other sections of the volute. Under the off-design operating conditions, the main fluctuation frequency at the inlet and outlet of the impeller is still the blade passing frequency, while that at the tongue is between the twice shaft frequency and the blade passing frequency, fluctuation amplitudes are both larger than those under the design operating condition. Under the design operating condition, the radial force on the impeller is the minimum, however, the Axial force increases with the increase of Flow rate. The distributions of unsteady pressure in volute type Axial Flow Pump are different with general centrifugal or Axial Flow Pump
Weidong Shi - One of the best experts on this subject based on the ideXlab platform.
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a study on tip leakage vortex dynamics and cavitation in Axial Flow Pump
Fluid Dynamics Research, 2017Co-Authors: Lei Shi, Desheng Zhang, Weidong Shi, Yongxin Jin, B P M Van EschAbstract:The tip leakage Flows and related cavitation in the tip region of an Axial-Flow Pump were investigated in detail using the numerical and experimental methods. The numerical results of the Pump model performance were in good agreement with experimental data. The Flow structures in the tip clearance were clarified clearly with detailed data involving the Axial velocity and turbulent kinetic energy. When depicting the feature of vortex core, the advanced vortex identification method λ 2-criterion was used. Simultaneously, the minimum tension criterion was also applied to predict the cavitation inception for different Flow rates and it is consistent with the distributions of vorticity and pressure in the vortex core. The roll-up process of TLV is highly three-dimensional and the entrainment would follow different paths. Then, both the numerical and experimental approaches show the cavitation patterns for different cavitation conditions, and it also finds that slight cavitation would promote the development of tip leakage vortex (TLV) while the TLV seems to be eliminated for a low cavitation number, especially before a specific location of blade tip due to the blade loading change induced by cavitation possibly.
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Numerical simulation and optimization of solid-liquid two-phase Flow in a back-swept Axial-Flow Pump
Thermal Science, 2017Co-Authors: Desheng Zhang, Weidong Shi, Qiang Pan, Rui-jie Zhang, Xing JinAbstract:The simulation study is proposed to analyze the wear property of the Axial Flow Pump using the sewage as medium. Different Axial Flow Pumps are designed with different back-swept angles, of which are 40?, 65?, and 90?. Numerical simulation results showed the relationship between solid volume fraction and back-swept angle on the pressure/suction surface, as well as the particle diameter. To validate the correctness of numerical investigation, the result of the 65? backswept blade model was compared with a sludge Axial Flow Pump in sewage treatment plant, which showed fair agreement with the simulated results.
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numerical and experimental investigation of tip leakage vortex trajectory and dynamics in an Axial Flow Pump
Computers & Fluids, 2015Co-Authors: Desheng Zhang, Weidong Shi, B P M Van Esch, Lei Shi, Michel DubuissonAbstract:Abstract Tip leakage vortex (TLV) in an Axial Flow Pump was simulated by using the shear-stress transport (SST) k – ω turbulence model with a refined high-quality structured grid at different Flow rate conditions. The TLV trajectories were obtained by using the swirling strength method corresponding to the cross-sections of streamlines of the TLV. High-speed photography experiments were conducted to observe the TLV trajectory based on cavitation tracing bubbles in an Axial Flow Pump with a transparent casing. The TLV trajectories predicted by the SST k – ω turbulence model agreed well with the visualization results. The numerical and experimental results show that the starting point of the TLV is near the leading edge at part-load Flow rate condition ( Q / Q BEP = 0.85 ), and it moves towards the trailing edge to approximately 20% blade chord at the design Flow rate condition ( Q / Q BEP = 1.0 ). At large Flow rate conditions ( Q / Q BEP = 1.2 ), the starting point of the TLV shifts to about 40% blade chord, and the relative angle between the TLV trajectory and the blade chord is gradually reduced with the increased Flow rate. Detailed statistics of the fluid dynamics of the end-wall shear layer and the TLV at design and off-design conditions were discussed based on the numerical results. The shear layer and jetting Flow in the tip gap are highly affected by the pressure difference between the pressure side (PS) and suction side (SS). It was also found that the distributions of static pressure, turbulent kinetic energy (TKE) and vorticity inside the TLV core are associated with the TLV structure which is affected by blade loading and operation conditions of the Axial Flow Pump.
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study on tip leakage vortex in an Axial Flow Pump based on modified shear stress transport k ω turbulence model
Thermal Science, 2013Co-Authors: Desheng Zhang, Weidong Shi, Dazhi Pan, Peipei ShaoAbstract:The tip leakage vortex structure and trajectory in an Axial Flow Pump were investigated numerically and experimentally based on the modified shear stress transport k-ω turbulence model. Numerical results were compared with the experimental leakage vortex trajectories, and a good agreement was presented. The detailed trajectories of tip leakage vortex show that the starting point of tip leakage vortex occurs near the leading edge at small Flow rate, and it moves from leading edge to about 30% chord length at design Flow rate. At larger Flow rate condition, the starting point of tip leakage vortex shifts to the middle of chord.
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Performance Prediction and Experimental Verification of Axial Flow Pump Based on CFD
Applied Mechanics and Materials, 2012Co-Authors: Desheng Zhang, Guang Jian Zhang, Weidong ShiAbstract:The full Flow field numerical simulation of the Axial-Flow Pump model is carried out to predict the Pump performance based on RNG k-e model and SIMPLE algorithm and the method of calculating head and efficiency. The numerical results show that the head and efficiency prediction curves have a good agreement with the experimental results. In the optimal operating condition, the prediction error of head is 0.04% and the efficiency error is 0.39% which could meet the requirements of engineering applications. The prediction error based on RNG k-e turbulence model is larger in the off-design condition owing to the complex Flow field of Axial-Flow Pump. The predicted head is lower than the experimental results in the small Flow rate conditions and its maximum error is 5.12%, while is higher than the experimental data in the large Flow rate conditions and its maximum error is 17.39%. The conclusions will provide the basis and reference for the performance prediction of Axial-Flow Pumps based on CFD.
Hong Ming Zhang - One of the best experts on this subject based on the ideXlab platform.
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An Investigation of the Vortex in a Submersible Axial Flow Pump Impeller
Applied Mechanics and Materials, 2015Co-Authors: Hong Ming Zhang, Li Xiang ZhangAbstract:The paper presents numerical simulation of the vortex in a submersible Axial Flow Pump impeller using OpenFoam code. A mixture assumption and a finite rate mass transfer model were introduced to analyze vortex. The finite volume method is used to solve the governing equations of the mixture model and the pressure-velocity coupling is handled via a Pressure Implicit with Splitting of Operators (PISO) procedure. Simulation results have shown that the cavitation may occur on the lower portion of impeller suction side. And the blade channel vortex will be formed in the impeller. It can induce the pressure pulsation in the impeller and can result in reduced efficiency of the submersible Axial Flow Pump.
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Numerical Simulation of Unsteady Flow in a Submersible Axial Flow Pump
Applied Mechanics and Materials, 2013Co-Authors: Xiao Xu Zhang, Hong Ming ZhangAbstract:To make the submersible Axial Flow Pump have better performance, it is very significant to know about the Flowing distributions. Based on N-S equations and Standard turbulence model and SIMPLE algorithm, a CFD analysis was made of the full Flow passage in this type of Pump. The study result shows the Flow rule and will provide a guide for the designing and the producing practice.
Cao Weidong - One of the best experts on this subject based on the ideXlab platform.
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Distribution of unsteady pressure in volute type Axial Flow Pump
Journal of Vibroengineering, 2018Co-Authors: Cao Weidong, Yao Lingjun, Zhang QianAbstract:In order to study the distribution of unsteady pressure in volute type Axial Flow Pump, the k-e turbulence model was applied, and ANSYS CFX was provided for numerical simulation calculation. Experiments of external characteristics and pressure fluctuation have been done to verify the results of numerical simulation. The results show that under the design operating condition, the main fluctuation frequencies in the volute, at the inlet and outlet of the impeller are the blade passing frequency. The amplitudes of fluctuation at the inlet of the impeller decrease gradually from the rim to the hub, while those at the export decrease firstly and then increase, the amplitudes at the tongue are much higher than that at other sections of the volute. Under the off-design operating conditions, the main fluctuation frequency at the inlet and outlet of the impeller is still the blade passing frequency, while that at the tongue is between the twice shaft frequency and the blade passing frequency, fluctuation amplitudes are both larger than those under the design operating condition. Under the design operating condition, the radial force on the impeller is the minimum, however, the Axial force increases with the increase of Flow rate. The distributions of unsteady pressure in volute type Axial Flow Pump are different with general centrifugal or Axial Flow Pump.
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Distribution of unsteady pressure in volute type Axial Flow Pump
'JVE International Ltd.', 2018Co-Authors: Cao Weidong, Yao Lingjun, Zhang QianAbstract:In order to study the distribution of unsteady pressure in volute type Axial Flow Pump, the k-ε turbulence model was applied, and ANSYS CFX was provided for numerical simulation calculation. Experiments of external characteristics and pressure fluctuation have been done to verify the results of numerical simulation. The results show that under the design operating condition, the main fluctuation frequencies in the volute, at the inlet and outlet of the impeller are the blade passing frequency. The amplitudes of fluctuation at the inlet of the impeller decrease gradually from the rim to the hub, while those at the export decrease firstly and then increase, the amplitudes at the tongue are much higher than that at other sections of the volute. Under the off-design operating conditions, the main fluctuation frequency at the inlet and outlet of the impeller is still the blade passing frequency, while that at the tongue is between the twice shaft frequency and the blade passing frequency, fluctuation amplitudes are both larger than those under the design operating condition. Under the design operating condition, the radial force on the impeller is the minimum, however, the Axial force increases with the increase of Flow rate. The distributions of unsteady pressure in volute type Axial Flow Pump are different with general centrifugal or Axial Flow Pump
