scholarly journals A Numerical Study on the Distribution and Evolution Characteristics of an Acoustic Field in the Time Domain of a Centrifugal Pump Based on Powell Vortex Sound Theory

2019 ◽  
Vol 9 (23) ◽  
pp. 5018 ◽  
Author(s):  
Chang Guo ◽  
Jingying Wang ◽  
Ming Gao
Keyword(s):  
Centrifugal Pump ◽  
Acoustic Field ◽  
Time Domain ◽  
Acoustic Pressure ◽  
Numerical Study ◽  
Source Region ◽  
Centrifugal Pumps ◽  
Acoustic Source ◽  
Evolution Characteristics ◽  
Source Component

The acoustic field distribution and evolution characteristics in a time domain inside a centrifugal pump are studied. During the fluid motion process, the acoustic source and acoustic pressure are basically less than 0, and the minimum value of the two parameters is distributed near the tongue. Additionally, the concentration, break, extend, migration and reaggregation phenomena of the minimum acoustic source region exist. Specifically, as the blade passes through the tongue, the minimum acoustic source region concentrates on the tongue firstly, then extends and migrates downstream slightly with the blade motion, and aggregates again around the tongue, which results in the similar evolution characteristics of acoustic pressure. Moreover, the standard deviation (STD) of acoustic source mainly focuses near the pressure side of blade tail and volute tongue, and the maximum STD is located at the tongue. Compared with the source component induced by stretching of the vortex, the source component induced by non-uniformity of fluid kinetic energy is closer to the overall acoustic source. Take the tongue as an example, at various rotational speeds, the STD proportions of the two components are about 5% and 95%, respectively. This study discusses the generation, distribution and evolution characteristics of acoustic field, which lays a foundation to analyze the acoustic field propagation mechanism of centrifugal pumps.

Numerical Study of a Fuel Centrifugal Pump with Variable Impeller Width for Aero-engines

2015 ◽  
Vol 32 (4) ◽  
Author(s):  
Bin Wang ◽  
Huasheng Guan ◽  
Zhifeng Ye
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Numerical Study ◽  
High Reliability ◽  
Low Flow ◽  
Centrifugal Pumps ◽  
Fuel Temperature ◽  
Low Efficiency ◽  
Aero Engines ◽  
Large Flow

AbstractAs typical pump with large flow rate and high reliability, centrifugal pumps in fuel system of aero-engines mostly regulate flow rate by flow bypass, which leads to low efficiency and large fuel temperature rise especially at low flow rate. An innovative fuel centrifugal pump with variable impeller width is a more effective way to regulate flow rate than flow bypass. To find external characteristics of the centrifugal pump with variable impeller width proposed in this paper, flow domain within the pump is simulated numerically and some primary performance parameters and their correlation are analyzed. Results show that flow rate of the pump can be regulated by variable impeller width and that efficiency for this scheme is higher than that for flow bypass. The higher outlet static pressure the pump runs at, the wider range of flow rates can be obtained with stronger nonlinear relationship between flow rate and impeller width.

Research of Unsteady Characteristics of Torque in Centrifugal Pumps

2019 ◽  
Author(s):  
Luo Yin ◽  
Han Yuejiang ◽  
Dong Jian
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Time Domain ◽  
Internal Flow ◽  
Operating Parameters ◽  
Centrifugal Pumps ◽  
Flow Rates ◽  
Operation Conditions ◽  
Unsteady Characteristics ◽  
Dominant Frequencies

Abstract Torque is one of the most important operating parameters of centrifugal pumps which reflects the internal flow rate of centrifugal pumps. In order to explore the unsteady characteristics of torque of centrifugal pumps based on sensorless monitoring technology, a series of accurate measurements of torque of experimental centrifugal pump were carried on based on the test data collected. The frequency characteristic spectrums of torque were established and analyzed under different operation conditions. The analysis results shows that the torque of the experimental centrifugal pump varies approximately linearly with the increase of flow rate in time domain. Besides, a gentle trend of the torque fluctuation is also founded. Through frequency domain, the analysis results show that the dominant frequencies under different flow rates and cavitation conditions are all axial frequencies. The magnitude of amplitude has nothing to do with the flow rates or the cavitation conditions, and the internal flow rates of centrifugal pumps have no obvious effects on the fundamental frequency of torque of centrifugal pumps.

scholarly journals Numerical Study of Pressure Fluctuation and Unsteady Flow in a Centrifugal Pump

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 354 ◽  
Author(s):  
Ling Bai ◽  
Ling Zhou ◽  
Chen Han ◽  
Yong Zhu ◽  
Weidong Shi
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Pump ◽  
Pressure Fluctuation ◽  
Static Pressure ◽  
Numerical Study ◽  
Pressure Fluctuations ◽  
Flow Patterns ◽  
Lower Number ◽  
Centrifugal Pumps ◽  
Impeller Blade

A pump is one of the most important machines in the processes and flow systems. The operation of multistage centrifugal pumps could generate pressure fluctuations and instabilities that may be detrimental to the performance and integrity of the pump. In this paper, a numerical study of the influence of pressure fluctuations and unsteady flow patterns was undertaken in the pump flow channel of three configurations with different diffuser vane numbers. It was found that the amplitude of pressure fluctuation in the diffuser was increased gradually with the increase in number of diffuser vanes. The lower number of diffuser vanes was beneficial to obtain a weaker pressure fluctuation intensity. With the static pressure gradually increasing, the effects of impeller blade passing frequency attenuated gradually, and the effect of diffuser vanes was increased gradually.

Numerical Study of Solid Particle Erosion in a Centrifugal Pump for Liquid–Solid Flow

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Fen Lai ◽  
Yu Wang ◽  
Saeed A. EI-Shahat ◽  
Guojun Li ◽  
Xiangyuan Zhu
Keyword(s):  
Centrifugal Pump ◽  
Solid Particle ◽  
Numerical Study ◽  
Middle Part ◽  
Economic Losses ◽  
Solid Particle Erosion ◽  
Centrifugal Pumps ◽  
Particle Erosion ◽  
Solid Flow ◽  
Severe Erosion

Solid particle erosion is a serious issue in centrifugal pumps that may result in economic losses. Erosion prediction in centrifugal pump is complex because the flow field inside it is three-dimensional (3D) unsteady and erosion can be affected by numerous factors. In this study, solid particle erosion of the entire centrifugal pump for liquid–solid flow is investigated numerically. Two-way coupled Eulerian–Lagrangian approach is adopted to calculate the liquid–solid interaction. The reflection model proposed by Grant and Tabakoff and the erosion model proposed by the Erosion/Corrosion Research Center are combined to calculate the erosion rate and predict the erosion pattern. Results show that for the baseline case, the inlet pipe is the least eroded component, whereas the impeller is the most eroded component. The highest average and maximum erosion rates occur at the hub of impeller. The most severe erosion region of a blade is the leading edge with a curvature angle that varies from 55 deg to 60 deg. The most severe erosion region of a volute is in the vicinity of a curvature angle of 270 deg. The impeller erosion pattern, especially the middle part of the hub and the vicinity of the blade pressure side, can be greatly influenced by operation parameters, such as flow rate, particle concentration, and particle size.

scholarly journals Experimental Investigation on the Acoustic Scattering Matrix for a Centrifugal Pump

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1489
Author(s):  
Guidong Li ◽  
Jorge Parrondo ◽  
Yang Wang
Keyword(s):  
Centrifugal Pump ◽  
Sound Source ◽  
Acoustic Pressure ◽  
Fluid Dynamic ◽  
Acoustic Scattering ◽  
Scattering Matrix ◽  
Acoustic Properties ◽  
Pressure Waves ◽  
Centrifugal Pumps ◽  
Dynamic Noise

Fluid-dynamic noise in centrifugal pumps as a significant sound source in piping systems has gained high attention due to the requirements of vibration and noise reduction in many fields. The acoustic characteristics of the fluid-dynamic noise from pumps are bound to be affected by the pipe ports and other piping components during the operation of the pump system. Therefore, the direct measurement of pressure pulsations in the pipeline of a test pump does not directly reflect the acoustic properties of the pump itself, because the coupling effects of the hydraulic system, which can even cause standing waves, may be seriously misleading in some situations. In this paper, an alternative experimental method has been applied to identify the so-called acoustic scattering matrix of a laboratory centrifugal pump. The elements of the scattering matrix characterize how the acoustic pressure waves are transmitted or reflected from the pump ports, i.e., it summarizes the passive acoustic properties of the pumps. For the tests, the test pump was connected in parallel to another auxiliary pump driven with a variable-frequency that played the role of an external sound source. The acoustic pressure waves induced in the suction and discharge pipes were mathematically decomposed into the corresponding incoming and exiting pressure waves travelling in the positive (P+) and negative (P−) directions respectively, by means of the two-microphone procedure. This paper shows the elements of the scattering matrix determined for the test pump as a function of frequency. These results represent a reference for subsequent theoretical research on the acoustic scattering matrix of centrifugal pumps.

scholarly journals Numerical Study of the Performance Loss of A Centrifugal Pump Carrying Emulsion

2021 ◽  
Vol 321 ◽  
pp. 01010
Author(s):  
Lila Achour ◽  
Mathieu Specklin ◽  
Idir Belaidi ◽  
Smaine Kouidri
Keyword(s):  
Centrifugal Pump ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Performance Degradation ◽  
Operating Conditions ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Performance Loss ◽  
Cfd Models ◽  
Phase Liquid

The performance and hydrodynamic behavior of centrifugal pumps when handling two-phase liquid-liquid flow and emulsion remain relatively unexplored, although they are of fundamental importance in optimizing the operating conditions of these pumps. Hence, this study aims at investigating the performance degradation of a centrifugal pump under emulsion flow by combined means of analytical and computational fluid dynamic (CFD) models. The analytical approach is based on internal energy loss equations while the CFD approach models the emulsion as a continuous and homogeneous single-phase fluid exhibiting shear thinning behavior. The results give a good insight into the performance degradation of such a system, especially at the best efficiency point (BEP).

Effect of semi-open impeller side clearance on centrifugal pump cavitation inception

2018 ◽  
Vol 1 (2) ◽  
pp. 24-39
Author(s):  
A. Farid ◽  
A. Abou El-Azm Aly ◽  
H. Abdallah
Keyword(s):  
Centrifugal Pump ◽  
Static Pressure ◽  
Rotation Speed ◽  
Centrifugal Pumps ◽  
Severe Condition ◽  
Cavitation Inception ◽  
Total Input ◽  
Input Pressure ◽  
Pump Head ◽  
Pump Pressure

Cavitation in pumps is the most severe condition that centrifugal pumps can work in and is leading to a loss in their performance.  Herein, the effect of semi-open centrifugal pump side clearance on the inception of pump cavitation has been investigated.  The input pump pressure has been changed from 80 to 16 kPa and the pump side clearance has been changed from 1 mm to 3 mm at a rotation speed of 1500 rpm. It has been shown that as the total input pressure decreased; the static pressure inside the impeller is reduced while the total pressure in streamwise direction has been reduced, also the pump head is constant with the reduction of the total input pressure until the cavitation is reached. Head is reduced due to cavitation inception; the head is reduced in the case of a closed impeller with a percent of 1.5% while it is reduced with a percent of 0.5% for pump side clearance of 1mm, both are at a pressure of 20 kPa.   Results also showed that the cavitation inception in the pump had been affected and delayed with the increase of the pump side clearance; the cavitation has been noticed to occur at approximate pressures of 20 kPa for side clearance of 1mm, 18 kPa for side clearances of 2mm and 16 kPa for 3mm.

scholarly journals Experimental and numerical study of acoustic pressure distribution in a sonochemical reactor

2021 ◽  
Vol 1809 (1) ◽  
pp. 012025
Author(s):  
M O Kuchinskiy ◽  
T P Lyubimova ◽  
K A Rybkin ◽  
O O Fattalov ◽  
L S Klimenko
Keyword(s):  
Pressure Distribution ◽  
Acoustic Pressure ◽  
Numerical Study

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 Design and Optimization of a Centrifugal Pump for Slurry Transport Using the Response Surface Method

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 60
Author(s):  
Khaled Alawadhi ◽  
Bashar Alzuwayer ◽  
Tareq Ali Mohammad ◽  
Mohammad H. Buhemdi
Keyword(s):  
Response Surface ◽  
Centrifugal Pump ◽  
Industrial Applications ◽  
Pump Efficiency ◽  
Optimized Design ◽  
Centrifugal Pumps ◽  
Local Pressure ◽  
Design And Optimization ◽  
Geometry Characteristic ◽  
Line Design

Since centrifugal pumps consume a mammoth amount of energy in various industrial applications, their design and optimization are highly relevant to saving maximum energy and increasing the system’s efficiency. In the current investigation, a centrifugal pump has been designed and optimized. The study has been carried out for the specific application of transportation of slurry at a flow rate of 120 m3/hr to a head of 20 m. For the optimization process, a multi-objective genetic algorithm (MOGA) and response surface methodology (RSM) have been employed. The process is based on the mean line design of the pump. It utilizes six geometric parameters as design variables, i.e., number of vanes, inlet beta shroud, exit beta shroud, hub inlet blade draft, Rake angle, and the impeller’s rotational speed. The objective functions employed are pump power, hydraulic efficiency, volumetric efficiency, and pump efficiency. In this reference, five different software packages, i.e., ANSYS Vista, ANSYS DesignModeler, response surface optimization software, and ANSYS CFX, were coupled to achieve the optimized design of the pump geometry. Characteristic maps were generated using simulations conducted for 45 points. Additionally, erosion rate was predicted using 3-D numerical simulations under various conditions. Finally, the transient behavior of the pump, being the highlight of the study, was evaluated. Results suggest that the maximum fluctuation in the local pressure and stresses on the cases correspond to a phase angle of 0°–30° of the casing that in turn corresponds to the maximum erosion rates in the region.

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