The action mechanism of rotor–stator interaction on the hydraulic and hydroacoustic characteristics of the guide vane in a jet centrifugal pump

2020 ◽  
Vol 34 (34) ◽  
pp. 2050396
Author(s):  
Rong Guo ◽  
Rennian Li ◽  
Renhui Zhang ◽  
Wei Han
Keyword(s):  
Flow Field ◽  
Transient Flow ◽  
Guide Vane ◽  
Centrifugal Pumps ◽  
Action Mechanism ◽  
Exterior Field ◽  
Outlet Angle ◽  
Rotor Stator Interaction ◽  
Wrap Angle ◽  
Hydrodynamic Noise

The aim of this study was to investigate the action mechanism of the rotor–stator interaction (RSI) in the transient flow field and hydrodynamic noise field of the guide vane in jet centrifugal pumps (JCPs). The numerical method of CFD (computational fluid dynamics), coupled with CFA (computational fluid acoustics), was used to analyze the correlation between the impeller parameters and the flow/sound characteristics of the guide vane. The results show that on the inlet surface of the guide vane, an impeller with fewer blades, a smaller wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for reducing the pressure fluctuation intensity. When the guide vane geometry is constant, the evolution processes of the transient flow field inside the static and dynamic cascades are mainly related to the blade number and speed of the impeller. An impeller with more blades, a larger wrap angle, a smaller outlet angle and a smaller outlet diameter is beneficial for improving the flow field distribution in the dynamic and static cascades. The hydrodynamic noise in the interior field is mainly related to the fluctuation characteristics of the transient flow field, but that in the exterior field is related not only to the fluctuation characteristics of the transient flow field, but also to the structural properties of the JCP pump body. The hydrodynamic noise in the exterior field presents an obvious dipole symmetrical distribution on the meridional plane, and the minimum value appears in the direction of the rotation axis because of the symmetrical structural characteristics of the pump body. The modal-shaped features of the JCP lead to a sidelobe phenomenon on the sagittal plane.

scholarly journals The Action Mechanism of Rotor–Stator Interaction on Hydraulic and Hydroacoustic Characteristics of a Jet Centrifugal Pump Impeller and Performance Improvement

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 465
Author(s):  
Guo ◽  
Li ◽  
Zhang ◽  
Han
Keyword(s):  
Flow Field ◽  
Pressure Fluctuation ◽  
Transient Flow ◽  
Guide Vane ◽  
Hydraulic Performance ◽  
Action Mechanism ◽  
Optimization Scheme ◽  
Fluctuation Intensity ◽  
Blade Number ◽  
Rotor Stator Interaction

The aim of this study was to investigate the action mechanism of the rotor–stator interaction (RSI) on the transient flow field and hydrodynamic noise field inside the impeller of jet centrifugal pumps (JCPs) and optimize effects of the guide vane on the hydraulic and hydroacoustic characteristics of the impeller. The numerical method of CFD (computational fluid dynamics) coupled with CFA (computational fluid acoustics) was used to analyze the correlation between the guide vane and the flow/sound performances of the impeller. The orthogonal test method, with the hydroacoustic performance of the impeller taken as the objective, was used to optimize the structural parameters of the guide vane for the stability of the hydraulic performance of the JCP. The results show that the RSI leads to a significant increase in the hydroacoustic level of the impeller, but it is indispensable for improving the hydraulic performance of the pump. The RSI effect on the fluctuation intensity of the transient flow field inside the impeller is much more sensitive than the time-average, and the fluctuation intensity of the flow field is positively correlated with the vortex intensity inside the impeller. When the impeller geometry is constant, the evolution processes of the flow field inside the impeller are mainly related to the blade number of the guide vane; when the number of guide vanes is given, the RSI effect on the hydroacoustic characteristic of the impeller is characterized by a positive correlation between the total sound pressure level (SPL) and the fluctuation intensity of the flow field. The frequency spectrum characteristics of the hydroacoustic SPL of the impeller are not consistent with the pressure fluctuation characteristics inside the impeller. The pressure fluctuation characteristics are related not only to the blade number and speed of the impeller but also to its wake characteristics determined by the guide vane. The optimization scheme for the stable hydraulic performance of the JCP significantly reduced the total SPL of the impeller compared with the original scheme, which verifies the feasibility of using the weight matrix optimization method to obtain the global optimization scheme.

Effects of Blade Outlet Width on Flow Field and Characteristic of Centrifugal Pumps

2009 ◽  
Author(s):  
Ming-gao Tan ◽  
Hou-lin Liu ◽  
Shou-qi Yuan ◽  
Yong Wang ◽  
Kai Wang
Keyword(s):  
Flow Field ◽  
Flow Curve ◽  
High Efficiency ◽  
Field Analysis ◽  
Centrifugal Pumps ◽  
Research Results ◽  
Rotor Stator Interaction ◽  
Nominal Condition ◽  
Specific Speed ◽  
Width Change

The present deficiency about numerical simulation research on blade outlet width of centrifugal pumps is pointed out. In the case of different outlet widths, the flow field in six centrifugal pumps whose specific speed vary from 45 to 260 are simulated by using commercial code FLUENT and the characteristics are predicted. The standard k-ε turbulence model and SIMPLEC algorithm are chosen in FLUENT. The simulation is steady and moving reference frame is used to consider rotor-stator interaction. The research results show that the change of impeller outlet width has obvious impacts on characteristics at design point, flow field and the shape of performance curves. At nominal condition, the change of outlet width has more important effects on moderate specific speed centrifugal pumps. The flow field analysis indicates that blade outlet width change has an important effect on the location and area of low pressure region behind the blade inlet, jet-wake structure in impellers, the secondary flow in volute cross section and the back flow in impellers. The head-flow curve becomes more flat with the increase of outlet width. For moderate and low specific speed centrifugal pumps, the high efficiency area of efficiency-flow curve get bigger with the increase of outlet width and the area will be constant within certain outlet width change scope for high specific speed centrifugal pump. The research results agree well with experiment results.

scholarly journals Numerical Investigation of Flow Field and Energy Loss in a Centrifugal Pump as Turbine

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jingze Li ◽  
Dongrong Meng ◽  
Xun Qiao
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Energy Loss ◽  
Entropy Generation ◽  
Flow Separation ◽  
Guide Vane ◽  
Great Influence ◽  
Internal Flow ◽  
Asymmetric Structure ◽  
Centrifugal Pumps

Centrifugal pumps as turbine (PAT) are widely used in petrochemical and water conservancy industries. The research on the internal flow field and energy loss of PAT is of great significance to improve the performance and efficiency of PAT. In this paper, experimental and numerical simulation methods are used to study the energy loss and flow field. The results show that the numerical simulation method can accurately simulate the internal flow field of PAT. And the entropy generation theory is applied to visualize the internal energy loss of PAT through the comparison of total pressure loss and entropy generation. The highest energy loss among PAT components is the guide vane. The loss in the guide vane is mainly caused by the flow separation caused by the wake of the guide vane and the asymmetric structure of the volute. The losses in the impeller are mainly due to flow separation and wake. Besides, the unsteady simulation results show that rotor-stator interaction has a great influence on the gap between the impeller and the guide vane. The research results provide a reference for the design of the PAT. This study is beneficial to studying the dynamic and static interference and PAT vibration to improve the stability of the PAT.

Influence of Guide Vane Wrap Angle Key Design Parameters on Hydraulic Performance of Nuclear Reactor Coolant Pump

2014 ◽  
Vol 721 ◽  
pp. 73-77 ◽  
Author(s):  
Wei Nan Jin ◽  
Rong Xie ◽  
Mu Ting Hao ◽  
Xiao Fang Wang
Keyword(s):  
Flow Field ◽  
Nuclear Reactor ◽  
Guide Vane ◽  
Three Dimensional ◽  
Internal Flow ◽  
Hydraulic Performance ◽  
Design Parameters ◽  
Coolant Pump ◽  
Reactor Coolant ◽  
Wrap Angle

To study the effects of guide vane with different vane wrap angles and relative positions of outlet edge on hydraulic performance of nuclear reactor coolant pump, three-dimensional steady numerical simulations were performed by using CFD commercial software Numeca. The results show that the vane wrap angle changes the head and power characteristics by changing the relative velocity angle in vane outlet. The inner flow field changes while the wrap angle changes. With the wrap angle increases, the shock loss in volute is reducing, but the friction loss in vane passages is getting large. So there exists an optimum wrap angle and relative positions of outlet edge that corresponds to the highest efficiency of a pump. Numerical simulation is performed with the two key design parameters optimized through surrogate model, the internal flow field is improved and then the hydraulic efficiency is improved.

scholarly journals The Influence of Blade Angle on the Performance of Plastic Centrifugal Pump

2020 ◽  
Vol 2020 ◽  
pp. 1-20 ◽  
Author(s):  
Jun Li ◽  
Lingfeng Tang ◽  
Yaoyao Zhang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Design Method ◽  
Structural Characteristics ◽  
Centrifugal Pumps ◽  
Dimensional Model ◽  
Working Pressure ◽  
Outlet Angle ◽  
Modulus Method ◽  
Inlet Angle

In order to obtain the influence of blade placement angle on the performance of plastic centrifugal pumps, this article used the velocity modulus method. Based on the method, the hydraulic design of the flow passage components of the plastic centrifugal pump was carried out, and the two-dimensional model and three-dimensional model diagram of the flow components were established. The flow field of the impeller model under different working conditions was simulated and the results were analyzed by ANSYS CFX. The influence of different fluid loads on the solid structure under design conditions on the structure characteristics of the impeller was studied by ANSYS Workbench. Impeller models with different outlet angles were established to study the influence of the outlet angle on the performance of pump, and fluid-structure interaction for different impeller models was utilized to study the influence of the outlet angle on the structural characteristics of the impeller. According to the Stepanoff velocity modulus method, considered the import prerotation, the wrap angle design method and the blade inlet angle design method were proposed. In order to study the influence of different inlet angles on the performance of pump, the inlet angle was changed to establish multiple sets of impeller models, 3D printing technology was used to print out each impeller, and performance experiments were performed on the pump equipped with the impeller. The result of the experiments showed that working pressure of plastic centrifugal pump exceeding 5 atm would cause impeller structure damage. When the outlet angle was 35°, the plastic centrifugal pump reached the highest efficiency of 81.0161% and the highest H of 35.8029. The maximum deformation caused by the flow field load on the impeller increased with the increase of the outlet angle. With the increase of the inlet angle, the efficiency and H of the plastic centrifugal pump were reduced. Under normal pressure load, the deformation of the impeller first decreased and then increased, and when β1 was 13°, the total deformation of the impeller was the smallest.

Study of Transient Behavior in Centrifugal Pump During Startup Period

2012 ◽  
Author(s):  
Yu-liang Zhang ◽  
Zu-chao Zhu ◽  
Bao-ling Cui ◽  
Yi Li
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Transient Flow ◽  
Three Dimensional ◽  
Transient Behavior ◽  
Operating Conditions ◽  
Pipe System ◽  
Rotor Stator Interaction ◽  
Startup Period

To explore the transient characteristic of a centrifugal pump with the specific speed of 90 during startup period, the internal three-dimensional unsteady flow was solved by using CFD. Wherein to overcome the difficulty in implement of boundary conditions in numerical simulation, a closed-loop pipe system that includes a centrifugal pump was built to accomplish self-coupling calculation. The results show that at the very beginning of startup, flow rate rises slowly and non-dimensional head coefficient is much higher than quasi-steady value, the quasi-assumption can not be competent for predicting transient effect well. Moreover, the insufficient of energy conversion makes the evolvement of transient flow field lags behind that of quasi-steady flow field, i.e., kinetic energy can’t convert pressure energy in time during acceleration flow period. Rotor-stator interaction makes flow rate present slight fluctuation characteristic under stable operating conditions.

Numerical Investigation of Rotor-Stator Interaction in a High-Bypass Ratio Fan Stage

2013 ◽  
Author(s):  
Zhong Yang ◽  
Hengliang Wang ◽  
Jiachao Yan ◽  
Xiangyang Deng
Keyword(s):  
Transient Flow ◽  
Guide Vane ◽  
Field Investigation ◽  
Inlet Guide Vane ◽  
Unsteady Pressure ◽  
Pressure Distributions ◽  
Rotor Stator Interaction ◽  
Fan Blade ◽  
Transonic Fan ◽  
Bypass Ratio

Both steady and time-accurate simulations of the flow through a high-bypass ratio fan stage consisting of transonic fan rotor blade (FAN), outlet guide vane (OGV) of bypass duct, and inlet guide vane (IGV) of low-pressure compressor (LPC) are performed at design operating point to address the fundamental questions regarding the impacts of unsteady rotor-stator interactions. The original ratios of fan blade number to OGV and IGV vane numbers are scaled to avoid the full wheel computation, thus reducing the amount of time-accurate computation effort. The comparison between time-averaged unsteady results and steady results shows minor differences in the performance of bypass and core ducts. The transient flow field investigation shows that the unsteady interaction between FAN and IGV is much stronger than that in the bypass duct. Considering aerodynamic response and excitation mechanism due to rotor-stator interaction, the unsteady pressure distributions are examined. The time traces and frequency contents of the unsteady pressure show complex rotor-stator interaction arising from the incoming wakes and potential effects of downstream blade rows.

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.

scholarly journals Analysis of the Influence of Different Bionic Structures on the Noise Reduction Performance of the Centrifugal Pump

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 886
Author(s):  
Cui Dai ◽  
Chao Guo ◽  
Yiping Chen ◽  
Liang Dong ◽  
Houlin Liu
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Centrifugal Pump ◽  
Great Influence ◽  
Frequency Doubling ◽  
Sound Field ◽  
Internal Flow ◽  
Test System ◽  
Centrifugal Pumps ◽  
External Characteristics

The strong noise generated during the operation of the centrifugal pump harms the pump group and people. In order to decrease the noise of the centrifugal pump, a specific speed of 117.3 of the centrifugal pump is chosen as a research object. The bionic modification of centrifugal pump blades is carried out to explore the influence of different bionic structures on the noise reduction performance of centrifugal pumps. The internal flow field and internal sound field of bionic blades are studied by numerical calculation and test methods. The test is carried out on a closed pump test platform which includes external characteristics and a flow noise test system. The effects of two different bionic structures on the external characteristics, acoustic amplitude–frequency characteristics and flow field structure of a centrifugal pump, are analyzed. The results show that the pit structure has little influence on the external characteristic parameters, while the sawtooth structure has a relatively great influence. The noise reduction effect of the pit structure is aimed at the wide-band noise, while the sawtooth structure is aimed at the discrete noise of the blade-passing frequency (BPF) and its frequency doubling. The noise reduction ability of the sawtooth structure is not suitable for high-frequency bands.

A new dynamic mesh algorithm for studying the 3D transient flow field of tilting pad journal bearings

2016 ◽  
Vol 230 (12) ◽  
pp. 1470-1482 ◽  
Author(s):  
Mengxuan Li ◽  
Chaohua Gu ◽  
Xiaohong Pan ◽  
Shuiying Zheng ◽  
Qiang Li
Keyword(s):  
Flow Field ◽  
Equilibrium Position ◽  
Transient Flow ◽  
Journal Bearings ◽  
Dynamic Mesh ◽  
Static Equilibrium ◽  
Time Step ◽  
Tilting Pad ◽  
Grid Nodes ◽  
Tilting Pad Journal Bearings

A new dynamic mesh algorithm is developed in this paper to realize the three-dimensional (3D) computational fluid dynamics (CFD) method for studying the small clearance transient flow field of tilting pad journal bearings (TPJBs). It is based on a structured grid, ensuring that the total number and the topology relationship of the grid nodes remain unchanged during the dynamic mesh updating process. The displacements of the grid nodes can be precisely recalculated at every time step. The updated mesh maintains high quality and is suitable for transient calculation of large journal displacement in FLUENT. The calculation results, such as the static equilibrium position and the dynamic characteristic coefficients, are consistent with the two-dimensional (2D) solution of the Reynolds equation. Furthermore, in the process of transient analysis, under conditions in which the journal is away from the static equilibrium position, evident differences appear between linearized and transient oil film forces, indicating that the nonlinear transient calculation is more suitable for studying the rotor-bearing system.

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