Pump Vibration Research Articles

The Effect of Air–Water Mixture on the Dynamic Response of a Hydrodynamic Journal Bearing With Inclined Grooves

Abstract Water-lubricated hydrodynamic journal bearings with deep inclined grooves are often used to support radial loads and dampen pump vibrations in nuclear power plants. The inclined grooves increase the pumping effect of the lubricant thus reducing wear and friction during rotor startup and coast-down. The deep grooves also facilitate the removal of debris without damaging the bearing. The load capacity and the stability of this type of bearing are studied in the present work. A sensitivity study of the impact of the number of grooves on bearing performance underlined the superiority of the journal bearing with two inclined grooves. Moreover, these journal bearings may operate with a mixture of water and air. This compressible two-phase lubricant will modify the load capacity and the stability of the journal bearing. The impact of the ingested volume fraction of air is therefore investigated. A physical model of the homogeneous air–water mixture linking the local air volume fraction with the pressure was used in conjunction with the numerical solution of the compressible Reynolds equation on an unstructured grid. It was found that the air ingestion in the two-inclined grooves journal bearing decreases the load capacity but improves the stability for mild and low loads.

Rotor fault diagnosis of centrifugal pumps in nuclear power plants based on CWGAN-GP-CNN for imbalanced dataset

As a crucial device in nuclear power plants, centrifugal pumps undertake the critical role of cooling water circulation. Centrifugal pump rotor misalignment and unbalanced faults cause pump performance degradation, vibration increase, and equipment damage, thus seriously affecting the safety and reliability of nuclear power plants. In the process of centrifugal pump rotor fault, the difficulty in obtaining data samples and the limited amount of data can lead to an imbalance problem between the quantity of normal state and fault state samples in the dataset. In order to solve the problem, this paper proposed a CWGAN-GP model for generating rotor fault data based on CGAN and WGAN-GP models, and combined it with a two-stream CNN model to realize the rotor fault diagnosis with an imbalanced dataset. The quality and performance of the data generated by the proposed method were evaluated and validated in terms of visualization analysis, statistical indicators, and comparison with different data generation models. The results show that the CWGAN-GP model can generate high-quality data. Meanwhile, compared with other models on datasets with different degrees of imbalance, the two-stream CNN model is more effective in fault diagnosis on the expanded dataset by the CWGAN-GP model, and the improvement of fault diagnosis accuracy ranges from 1.40% to 13.33%.

Analysis of the effect of cavitation on internal fluid excitation characteristics of centrifugal pumps

To explore the influence of cavitation on the internal fluid excitation characteristics of pumps, numerical simulations and performance testing evaluations were performed on the IS65-50-125 centrifugal pump. The prototype pump's exterior characteristic and cavitation performance curves, as well as its bubble volume distribution, were successfully replicated using numerical computations. The effect of cavitation on the internal pressure pulsation characteristics of the centrifugal pump under various operating situations was comprehensively investigated, indicating a relationship between the degree of cavitation and the root mean square values of pressure pulsation. Special emphasis was placed on the changes in features at intermediate and high frequencies, as well as the processes of rising bubble volume and vortex shedding at the impeller trailing edge on pressure pulsation. To validate the simulation results, a centrifugal pump vibration and noise testing platform was built, and studies on vibration intensity and internal sound field noise were conducted. The experimental results revealed that the vibration intensity and internal sound field sound pressure level of the centrifugal pump rose as cavitation conditions deteriorated, confirming the modeling results. This study's significant innovation is the precise identification of the pump's performance changes under different operating conditions by monitoring pressure pulsation changes at various frequencies, as well as an in-depth discussion of the impact mechanism of cavitation phenomena on the internal fluid excitation behavior of centrifugal pumps. The study demonstrates differences in pressure pulsation characteristics on the suction and pressure sides under various cavitation situations, as well as the process of vortex creation and shedding generated by bubbles in the impeller input channel during severe cavitation. This gives new theoretical basis for pump vibration and noise reduction, as well as significant improvements in centrifugal pump performance and stability.

A Critical Analysis of Design for Reduction in Vibrations of Centrifugal Impellers

Centrifugal pumps are widely used for various applications. Numerous technical practices use centrifugal pumps, particularly when consistent and adaptable pump performance is required. Still, these can have several issues, including low efficiency when operated under off-design conditions and poor capitalization performance. These frequent transport mixtures, such as liquid and gas, and pure liquids. It is a well-known fact that several problems encountered by pumps in a pumping station are related to structural instability or impeller/blade failure. Vibrations can cause catastrophic failures in the impeller, so these must be kept to a minimum while designing the impeller. Vibration, cavitation, rough running, lower-than-expected efficiency, and shorter pump life can all be traced back to unfavorable process flow conditions. Although there are some design guidelines for pump configuration, the effects of fluctuating discharge on structural stability have yet to be investigated. An additional pressing problem is the identification of time cracks. Failure can occur due to cracks much before the design loads. In this work, we aim to investigate and analyze the centrifugal impeller design consideration. Using different methods for designing and modeling, we compared significant results and found the optimal solutions in which a centrifugal impellor can be designed. This work enables us to determine the best techniques and methods to overcome the problem of vibrations produced in the centrifugal impeller. This also helps us to understand the centrifugal pump's behavior and performance to improve its efficiency. Centrifugal impellors are compared across conditions, including free, forced, damped, and undamped systems. Three successful methods for designing and modeling a centrifugal impellor are proposed using these parameters. The methods of design and analysis provide predictions of the flow fields that are highly reliable. Regarding fluid distribution and pump efficiency, computational fluid dynamics provides various solutions that may be applied to impeller design. Using fluent software, we can better comprehend the pump's resonant operation. Blade mistuning is a severe problem that can be handled using the blade tip timing and strain gauge technique. Vibration and motor current signature analysis (MCSA) is also mentioned to investigate vibrational problems with the centrifugal impeller. Several strategies are discussed to lessen or eliminate the issue of vibrations in impellers. The limitations and disadvantages of using these techniques are discussed. The summary of results provides significant design and improvement in centrifugal pumps in the recent past.

ESP vibration prediction based on pump operating conditions in laboratory using machine learning

Electric Submersible Pump (ESP) is an effective artificial lift method of pumping medium to high production fluids. However, it is prone to failure because most of the system is located downhole. When mechanical defects start to develop, vibration signal changes. By examining the variation in vibration, component failures can be located and predicted. The objective of this study is to creates a machine learning model to predict ESP vibration using experimental data. The dataset that was utilized to create the model has more than a million data points collected from laboratory. Based on pump performance, the experimental data are divided into three groups: normal, advised and failing pump conditions. The model features are operating time, pump speed, oil flow rate, water flow rate, pump intake pressure, motor temperature, free gas percentage and liquid/mixture density and viscosity. Among the algorithms used to develop the model, random forests regression produces results with acceptable accuracy while not requiring too much computing power. Because of that, random forests regression was used for further optimization and simulation. The results of the model show that pump speed and operating time have the biggest effects of all the features. Due to the limited range of experimental data, in some cases, it is either unknown or unclear how the features affect ESP vibration, particularly in advised and failing pump conditions. The model's vibration predictions closely match the results of the experiments. This model can be used to forecast pump vibration under a particular operating condition by incorporating into the ESPSim program. The predicted vibration magnitude can be compared to the actual value to determine whether an ESP is in failing condition. With this information, the amount of downtime when the pump fails could be minimized. The extreme downhole conditions can also cause sensor cables to break and become incapable of transmitting data to the surface. Operators can use predicted ESP vibration to get an idea of the status of the pump.

Influence of different turbulence models on tip vortex prediction

Abstract Tip vortex cavitation usually occurs in marine propellers and axial-flow turbines, the cavitation in the tip vortex could potentially result in blade erosion, at the same time, it will cause the pump vibration and noise emission. The tip vortex mainly occurs in rotating machinery with complex three-dimensional flow, but the prediction of the hydrofoil tip vortex can provide a basis for the study of the blade tip vortex in rotating machinery by simplifying the blade model. Hence, in this paper, we use the commercial software CFX to investigate the impact of distinct turbulence models on the configuration of tip vortex distribution in the NACA 16-020 hydrofoil, including SST (Shear Stress Transport), DES (Detached Eddy Simulation), LES (Large Eddy Simulation) turbulence models which are widely used in the field of rotating machinery. At the same time, the axial and radial velocity distributions at different locations downstream of the tip of the hydrofoil are compared to analyse the effects on the velocity distribution near the vortex core line stemming from various turbulence models. By comparing with the experimental data, the most accurate turbulence model for tip vortex prediction is obtained, which will provide guidance for the next step tip vortex prediction and the control of tip vortex flow.

Model experimental study on special frequency of hydraulic pump working condition headcover for ultra-high head pump-turbine

Abstract With the accelerated construction of pumped-storage power stations, high-head and high-capacity pumped-storage units are gradually becoming the mainstream of development. When operated on-site, the high-head and high-capacity pumped-storage units reflect the phenomenon of special frequency of the head cover vibration of the water pump, which has attracted widespread attention from the industry. In order to deeply reveal the flow mechanism of pumped-storage units, model experiments on the head cover were conducted through the similarity conversion principle between the model and the prototype. The experiment results show that the occurrence of specific frequency in the Head cover of the water pump during operation is due to the rotating flow separation in the vaneless area.

Granular vibration pumping system for handling and characterizing particulate materials.

A unique setup for a granular vibration pumping system was developed to ease the installation into a wide variety of granular handling processes and provide flexible options for granular physics research. Although the granular vibration pumping system can notably lift granular materials with an oscillating pipe, the climbing mechanism and related granular physics are yet to be clarified thoroughly. The new setup employs an eccentric cam mechanism as the excitation source, a linear system with dust tolerance, and a recording system, making it simple, compact, and adaptable for extending experiments. The excitation mechanism generated a clear sinusoidal vibration in the pipe, realizing better reproducibility of the climbing motions of glass beads. Moreover, the compact design facilitates the close placement of multiple pipes vibrating individually, which affects the transport performance. In addition, various types of sample cells that store particles and the imaging system allow for the detailed observation of particle motions in the pipes and even the sample cells. This developed system provides easy and accurate tuning of the existing parameters of the granular vibration pumping system, as well as new options for a further understanding of granular physics.

Flow Characteristic Analysis of the Impeller Inlet Diameter in a Double-Suction Pump

Pumps are considered crucial mechanical devices in any industry. Especially, double-suction pumps, due to their high-flow design and high head, are utilized in diverse industrial sectors. However, despite these advantages, double-suction pumps are vulnerable to issues like losses, vibrations, and cavitation. Pump vibration is mainly caused by suction recirculation occurring at the impeller inlet. Therefore, this study investigates the impact of the impeller inlet design on enhancing the stability of double-suction pumps while expanding the operating flow range. Through a validated CFD study, the influence of the impeller inlet passage size on the head and efficiency was analyzed. Furthermore, research was conducted on the phenomenon of suction recirculation occurring at the impeller inlet, proposing design guidelines to minimize it, especially for operation at low flow rates. The results demonstrate that the ratio of the hub diameter to the shroud diameter at the impeller inlet significantly impacts the avoidance of recirculation at low flow rates. These findings are expected to contribute to improving the stability and efficiency of high-flow pumps.

Insight into blade tip vibration and deformation characteristics of boiler circulation pumps induced by tip leakage vortex under different tip clearances

For circulating pumps in large power plant boilers, tip leakage flow is the main cause of blade fatigue. To investigate the correlation between tip leakage vortex and blade fatigue, in this paper, the bidirectional fluid structure coupling method is used to simulate the full flow field of the boiler circulating pump under different tip clearance sizes. The accuracy of the delayed detached vortex simulation method is verified by combining the external characteristics and vibration characteristics of the pump. It is obtained that tip leakage vortex is the main cause of blade tip vibration and deformation. Under deep stall conditions, the increase in tip clearance size suppresses the vibration displacement of the blade leading edge, while the opposite is true under optimal conditions. After decomposing tip leakage vortex, it is found that the compression–expansion term played a major role in the deformation of the blade tip, while the viscous dissipation term and the stretching term mainly affected the vibration frequency. At optimal working conditions, the main frequency of blade vibration is basically consistent with the main frequency of vortex generation. In deep stall condition, as the tip clearance size increases, the amplitude of the vibration main frequency decreases and the number of harmonic frequencies decreases, while the optimal condition is the opposite.

P-702 Centrifugal Pump Damage Analysis Insights and Implications

Centrifugal pumps are widely used in industries for fluid transfer, operating on the rotation of an impeller driven by a prime mover. However, sudden performance drops and operational instability pose significant challenges, impacting overall system efficiency. Predictive maintenance relies on vibration analysis to assess rotating equipment condition, with vibration patterns indicating potential issues such as cavitation and corrosion. Prolonged cavitation leads to erosion of channel wall surfaces, resulting in structural damage. This study aims to address the knowledge gap in understanding the relationship between pump vibration, cavitation, and corrosion. Through comprehensive vibration analysis and examination of pump performance, our research identifies the mechanisms driving pump degradation. The findings highlight the critical role of predictive maintenance in mitigating pump failures and optimizing system performance. Highlights : Vibration analysis crucial for predictive maintenance: Identifying early signs of pump deterioration. Cavitation-induced erosion: Understanding the impact of prolonged cavitation on pump performance. Importance of proactive maintenance: Mitigating pump failures and optimizing system efficiency. Keywords : Centrifugal pumps, Vibration analysis, Cavitation, Corrosion, Predictive maintenance

Vibration Diagnostics for Predicting Pump Failures

This study investigates the predictive potential of specific vibration patterns in assessing the structural integrity of centrifugal pumps, vital for industrial fluid transport. Despite their importance, these pumps often encounter performance issues attributed to vibration-related damage such as cavitation and corrosion. Addressing this gap, we employ advanced vibration analysis techniques to identify distinct signatures indicative of cavitation and corrosion progression. Our research aims to provide an early detection tool for maintenance by understanding these patterns. Through our method, we reveal significant correlations between vibration patterns and pump condition, offering implications for extending pump lifespan and enhancing maintenance strategies in industries reliant on such machinery. Highlights: Centrifugal Pump Operation: Impeller rotation transfers fluid. Vibration Analysis Significance: Essential for predictive maintenance. Cavitation and Corrosion Effects: Trigger vibration, erode surfaces. Keywords: Centrifugal Pump, Corrosion, Vibration

Vibration Monitoring using Arduino Data Acquisition to Detect Anomalies in the Operation of Water Pump.

Arduino Data Acquisition (ADAQ) is a popular development device among hobbyists nowadays because of its cheap price. Arduino comes in many forms, and recently, Arduino has been used in many industries for many applications, including vibration monitoring. This study aimed to investigate feasibility of using an Arduino data acquisition to detect anomalies in the operation of a water pump. An Arduino Mega was used with an ADXL345 accelerometer attached to a water pump motor to measure vibration continuously. Vibration was measured with a sampling rate of 530 Hz. Water pump vibration data abnormal conditions were measured and analysed to determine the problem. Results showed that vibration during anomalies was significantly greater than that in normal conditions. This study concludes that Arduino Data Acquisition with ADXL345 can detect abnormal water pump running conditions.

The influence of blade curvature radius on the internal unsteady characteristics of a centrifugal pump

AbstractTo study the influence of the blade curvature radius on the flow‐induced vibration and noise of the centrifugal pump, the internal sound field of the IS 80‐65‐160 centrifugal pump was numerically calculated by adjusting the blade wrap angles to change the blade curvature radius. The RNG (Reynolds Time Average Simulation) turbulence model was selected for the numerical calculation of the centrifugal pump. The numerical simulation of the whole flow channel of the centrifugal pump was carried out using Ansys Fluent software, and the external characteristic curve of the centrifugal pump was obtained. The influence of different blade wrap angles on the internal pressure, velocity and Turbulent Kinetic Energy of the centrifugal pump was obtained. On the basis of the sound–structure coupling equation, the unsteady sound field of the centrifugal pump was calculated, and the time domain and frequency domain characteristics of the pressure pulsation at each monitoring point were obtained. The calculation results showed that the dynamic and static interference between the impeller and the volute tongue mainly caused the vibration of the centrifugal pump. By appropriately increasing the blade wrap angles, the pressure pulsation in the volute fluid domain could be effectively reduced. The vibration and noise test bench of the centrifugal pump was set up to verify the test. The experimental results showed that at the double‐blade frequency, the variation trend of the experimental value and the simulated value of the outflow flow‐induced noise of the centrifugal pump were consistent, which verified the accuracy of the sound field simulation calculation. When the blade wrap angle , it could effectively reduce the internal sound pressure level and the flow‐induced vibration and noise of the centrifugal pump. By adopting measures such as grid encryption at the position of the tongue, nonstationary calculation and comparison of different turbulence models, the accuracy of the calculation results of the internal flow field and sound field of the centrifugal pump is effectively improved, and the accuracy and reliability of the experimental results are ensured. The above research results had certain reference significance and application value for improving the working efficiency of centrifugal pumps and reducing flow‐induced vibration and noise.

Research on Vibration Reduction in the Transmission System of Plastic Centrifugal Pump

The inherent weakness in the deformation resistance of plastic centrifugal pumps makes them prone to vibrations. This study explores the impact of flow components on the vibrations of such pumps. Utilizing the given parameters, the primary structural parameters of the plastic centrifugal pump were calculated. The study focused on the torsional vibrations within the pump shaft transmission system, employing a silicone oil damper for vibration mitigation. A dual-mass forced torsion vibration model was developed for the pump shaft transmission system with the added damper. The optimal damping coefficient for this damper was determined, and its structural design was completed, including the creation of three-dimensional models and two-dimensional part drawings. Utilizing a ZT-3 type rotor test bench, a mathematical model correlating centrifugal pump speed with deflection was developed, and the effectiveness of various polynomials was assessed. The analysis showed that the optimal damping value for the silicone oil damper is 0.22. Compared to the system without the damper, the vibration frequency reduced by 10.45%, and the vibration amplitude decreased by 49.29%, demonstrating excellent vibration reduction effectiveness.

Complex well development technology using a vibration pump

This article deals with the application and efficiency of the unified pumping and vibration device type UNTVU-73 for the complex technology of well development, hydrodynamic research of formations and intensification of oil and gas tributaries. The principle of well blasting is based on the creation of deep controlled cyclic depressions on the formation, which makes it possible to clean the bottom of the formation from sand and drill mud particles. During the operation of the jet pump, controlled depressions can be created, pressure can be measured with depth gauges, real-time measurement of pressure reduction curves can be monitored and various samples can be taken for chemical analysis. The use of the pumping and vibration device makes it possible to develop wells without the use of piles or expensive nitrogen compressor units. The use of a jet pump makes it possible to conduct high-quality hydrodynamic research of wells.

Optimal techno-economic energy coordination of solar PV water pumping irrigation systems

In this study, a water pumping photovoltaic system (WPPVS) provided with a water storage tank is introduced to supply freshwater for drip irrigation in Farafra oasis, Egypt. A multi-objective K-means clustering based on non-sorting genetic algorithm is utilized to minimize both the loss of water supply probability and the total annual costs including capital and running costs. Due to the variability of the water flow rate, a techno-economic energy coordination is developed with particular attention to avoid vibration of water pumps. The economic feasibility is based on the tomato crop yield against the total cost of the drip irrigation system. Sensitivity analysis for dynamic head, crop price, and interest and inflation rates is conducted. At specific dynamic head of 6 m, the results revealed that the optimal design of the WPPVS pumps 10220 cubic meter of water for irrigation through the developed energy coordination against 18575 cubic meter with pump vibration which saves 45 % of the pumped water. This reflects its effect on a decrease of the pumped water for all dynamic head values. Furthermore, the vibration avoidance strategy allows the pump to operate at lower dynamic heads above the water threshold level in the well, which is not possible with the presence of vibrations.

Retracted: Simulation of Flow-Induced Vibration and Dynamic Performance of Circular-Arc Helical Gear Pump under Background of Machine Learning

Retracted: Simulation of Flow-Induced Vibration and Dynamic Performance of Circular-Arc Helical Gear Pump under Background of Machine Learning

ANALYSIS OF THE INFLUENCE OF THE DESIGN PARAMETERS OF THE UPPER STAGE LIQUID PROPELLANT ROCKET ENGINE PUMP ON ITS CAVITATION CHARACTERISTICS

Abstract. The phenomenon of cavitation is inherent in all vane machines, the working medium of which is liquid. With a certain combination of input pressure, flow rate, rotor speed, and the gas saturation of the working fluid in the vane machine, cavitation may occur. Cavitation negatively affects the power characteristics of the vane machines. It leads to a drop in the power parameters for the pumps and damage to their flowing parts. And also at times increases the pulsation of pressure at the pump outlet and vibration. This is especially dangerous for LPRE chambers, as the pulsation of pressure leads to the appearance of low-frequency oscillations of the chamber itself. Therefore, it is so important, even at the design stage, to determine the cavitation perfection of the LPRE vane pump and take measures to increase it.When developing the RD861K engine, high demands were placed on the power perfection of the oxidizer pump. The efficiency of the oxidizer pump RD861K should be 5% higher than that of the oxidizer pump RD861 (pump prototype).To increase the efficiency of the oxidizer pump of the RD861K engine, a number of design parameters was changed (compared to the prototype). These works were crowned with success, the required efficiency value was achieved. However, some of the taken measures had a negative impact on the cavitation perfection of the pump.This study is devoted to the analysis of the influence of the design parameters of the RD861K engine pump (which make it possible to increase its efficiency) on its cavitation properties. During the analysis, it was determined how the design parameters affect the nature of the cavitation characteristicof the oxidizer pump RD861K and RD861. It is also established how a concrete design change affects the value of the suction specific speedof the pump. In addition to the above studies, an analysis was made of cavitation characteristics of pumps operating on a gas-containing two-phase liquid. Based on the results of the analysis, the dependence of the decrease in therelativesuction specific speedof the pump on the amount of gas supplied to the inlet to the pump was constructed. The results of this study allow us to estimate the magnitude of cavitation pump failure at the design stage, depending on the design features of its flowing part when working liquid withoutgas and on the gas-liquid two-phase mixture.

Effect of Blade Trimming Length on the Performance of Marine Centrifugal Pump

To study the hydrodynamic characteristics of blade trimming length in centrifugal pumps, Delayed Detached Eddy Simulation (DDES) with nonlinear eddy viscosity was utilized to conduct unsteady calculations on the centrifugal pump. A comprehensive examination of the fluid dynamic properties of the centrifugal pump, including external features, flow conditions, and pressure fluctuations, was carried out. By applying the theory of entropy production, the areas of high energy loss within the centrifugal pump were identified, and the correlations between local entropy production, energy loss, and unsteady flow in different areas with varying blade trimming lengths were analyzed. The results indicate that with the increase in blade trimming length, under rated flow conditions, the head decreases by 1.8%, 3.2%, and 5.7% for different blade trimming lengths, respectively, compared to normal impellers. Similarly, the efficiency decreases by 0.5%, 0.8%, and 1.0% for different blade trimming lengths, respectively. Similar trends were observed under other working conditions as well. As the degree of blade trimming increases, the irreversible losses after the failure of the centrifugal pump also increase significantly, indicating that the flow inside the centrifugal pump becomes disorder. Blade trimming leads to a disorderly fluid flow inside the centrifugal pump, causing an increase in the radial force during operation, which in turn leads to an increase in vibration amplitude and affects its operational stability. Blade trimming failure has a significant impact on the frequency and amplitude of pressure pulsation, resulting in abnormal pressure pulsation and abnormal vibration of the centrifugal pump. Therefore, early warning and diagnosis of blade trimming can be achieved through pressure pulsation monitoring.