scholarly journals Numerical and Experimental Study on the Flow-Induced Noise Characteristics of High-Speed Centrifugal Pumps

2020 ◽  
Vol 10 (9) ◽  
pp. 3105 ◽  
Author(s):  
Qiaorui Si ◽  
Chunhao Shen ◽  
Xiaoke He ◽  
Hao Li ◽  
Kaile Huang ◽  
...  
Keyword(s):  
High Speed ◽  
Fluid Pressure ◽  
Internal Flow ◽  
Low Noise ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Rate Condition ◽  
Radiated Noise ◽  
Noise Characteristics ◽  
Flow Induced Noise

The development of low-noise pumps is essential to design quiet fluid delivery systems. Due to the complicated internal flow, the flow-induced noise characteristics of high-speed centrifugal pumps have not been well understood. Taking engine cooling pumps as an example model, experimental measurements are performed in a semi-anechoic room and a CFD/CFA calculation method is proposed to study the fluid-borne noise and radiated noise characteristics. In the speed range of 5000–6750 r/min, both the pump head and the dimensionless radiated noise characteristics conform to similar laws, and the highest efficiency point pump presents the lowest noise level. Consistent with the experimental results, the predicted radiated noise of the model pump presents dipole characteristics at the required flow rate condition. Moreover, the spectrum of fluid borne noise at pump outlet shows broadband characteristics but with obvious discrete peaks, which are not only related to the fluid pressure pulsation characteristics (6f0 and the multiple) at the low-frequency region, but also to the frequency of the structural mode (3000–6000 Hz region). Rotor-stator interaction of the pump flow field between the impeller and volute is the main reason of flow-induced noise; unstable flow also contributes to the broadband components in the noise spectrum.

scholarly journals Numerical and Experimental Investigation on Radiated Noise Characteristics of the Multistage Centrifugal Pump

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 793 ◽  
Author(s):  
Si ◽  
Wang ◽  
Yuan ◽  
Huang ◽  
Lin ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Noise Source ◽  
Low Noise ◽  
Pressure Level ◽  
Radiated Noise ◽  
Noise Characteristics ◽  
Flow Induced Noise ◽  
Multistage Pump

The radiated noise of the centrifugal pump acts as a disturbance in many applications. The radiated noise is closely related to the hydraulic design. The hydraulic parameters in the multistage pump are complex and the flow interaction among different stages is very strong, which in turn causes vibration and noise problems because of the strong hydraulic excitation. Hence, the mechanism of radiated noise and its relationship with hydraulics must be studied clearly. In order to find the regular pattern of the radiated noise at different operational conditions, a hybrid numerical method was proposed to obtain the flow-induced noise source based on Lighthill acoustic analogy theory, which divided the computational process into two parts: computational fluid dynamics (CFD) and computational acoustics (CA). The unsteady flow field was solved by detached eddy simulation using the commercial CFD code. The detailed flow information near the surface of the vane diffusers and the calculated flow-induced noise source was extracted as the hydraulic exciting force, both of which were used as acoustic sources for radiated noise simulation. The acoustic simulation employed the finite element method code to get the sound pressure level (SPL), frequency response, directivity, et al. results. The experiment was performed inside a semi-anechoic room with a closed type pump test rig. The pump performance and acoustic parameters of the multistage pump at different flow rates were gathered to verify the numerical methods. The computational and experimental results both reveal that the radiated noise exhibits a typical dipole characteristic behavior and its directivity varies with the flowrate. In addition, the sound pressure level (SPL) of the radiated noise fluctuates with the increment of the flow rate and the lowest SPL is generated at 0.8Qd, which corresponds to the maximum efficiency working conditions. Furthermore, the experiment detects that the sound pressure level of the radiated noise in the multistage pump rises linearly with the increase of the rotational speed. Finally, an example of a low noise pump design is processed based on the obtained noise characteristics.

scholarly journals Analysis and control of flow at suction connection in high-speed centrifugal pump

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668529 ◽  
Author(s):  
Wen-wu Song ◽  
Li-chao Wei ◽  
Jie Fu ◽  
Jian-wei Shi ◽  
Xiu-xin Yang ◽  
...  
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
High Speed ◽  
Internal Flow ◽  
Orifice Plate ◽  
Centrifugal Pumps ◽  
Pressure Area ◽  
Negative Effect ◽  
And Control ◽  
Experimental Data Analysis

The backflow vortexes at the suction connection in high-speed centrifugal pumps have negative effect on the flow field. Setting an orifice plate in front of the inducer is able to decrease the negative effect caused by backflow vortexes. The traditional plate is able to partially control the backflow vortexes, but a small part of the vortex is still in the inlet and the inducer. Four new types of orifice plates were created, and the control effects on backflow vortexes were analyzed. The ANSYS-CFX software was used to numerically simulate a high-speed centrifugal pump. The variations of streamline and velocity vectors at the suction connection were analyzed. Meanwhile, the effects of these plates on the impeller pressure and the internal flow field of the inducer were analyzed. Numerically, simulation and experimental data analysis methods were used to compare the head and efficiency of the high-speed pumps. The results show that the C-type orifice plate can improve the backflow vortex, reduce the low-pressure area, and improve the hydraulic performance of the high-speed pump.

Comparison of Inlet Curved Disk Arrangements for Suppression of Recirculation in Centrifugal Pump Impellers

2016 ◽  
Author(s):  
Munther Y. Hermez ◽  
Badih A. Jawad ◽  
Liping Liu ◽  
Vernon Fernandez ◽  
Kingman Yee ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
Operating Cost ◽  
Three Dimensional ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Pump Impeller ◽  
Flow Rates ◽  
Flow Recirculation ◽  
Flow Field Characteristics

The present work aims to numerically study the inlet flow recirculation and modified impeller interaction in a centrifugal pump. An optimization of modified shrouded impeller with curved disk arrangement to suppress the unsteady flow recirculation is pursued. This modification will enhance the impeller characteristics with a wider operation range at both low and high flow rates in a high speed centrifugal pump type. The unstable flow in the centrifugal pumps is a common problem that leads to damage in the pump’s internal parts, consequently increases the operating cost. At certain flow rates, generally below the Best Efficiency Point (BEP), all centrifugal pumps are subject to internal recirculation occurs at the suction and discharge areas of the impeller. For decades, experimental work has been done to investigate the complex three-dimensional flow within centrifugal pumps impellers, before computational work gains momentum due to advancement of computing power and improved numerical codes. In this study the impeller with a curved disk arrangement has been investigated by using a three-dimensional Navier-Stokes code with a standard k-ε turbulence model. The purpose is to evaluate and select the optimum impeller modification that would increase the pump suction flow rate range. Three-dimensional numerical Computational Fluid Dynamics (CFD) tools are used to simulate flow field characteristics inside the centrifugal pump and provide critical hydraulic design information. In the present work, ANSYS v.16.1 Fluent solver is used to analyze the pressure and velocity distributions inside impeller suction and discharge passages. The ultimate goal of this study is to manufacture and validate the most optimized and efficient centrifugal pump impeller with a curved disk. The best case curve identifies the highest increase of total pressure difference by 22.1%, and highest efficiency by 92.3% at low flowrates.

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

Study on Noise in New Roller Chain Drives

2012 ◽  
Vol 522 ◽  
pp. 598-601
Author(s):  
Wei Sun ◽  
Xiao Lun Liu ◽  
Wen Cheng Wang ◽  
Li Yan He ◽  
Jia Jun Liu
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
High Speed ◽  
Low Noise ◽  
The Other ◽  
Metal Mesh ◽  
Roller Chain ◽  
Polyurethane Composite ◽  
Noise Characteristics ◽  
The Impact

In order to mitigate the impact and the polygon effect of the chain and the sprocket during the meshing process and achieve the purpose of noise reduction, a Hlow noiseH nanostructured metal mesh-polyurethane composite material split roller chain was designed by means of changing structure and material of chain roller. Noise testing and frequency spectrum analysis were conducted, for the new roller chain and the other three kinds of the same specification chains with different structural rollers, on the closed force flow noise test bench researched and developed independently. The results show that the new roller chain can absorb some of the impact energy, and reduce vibration and noise of chain drive. The noise level generated by the new roller chain is significantly lower than the other tested roller chains, especially in high frequency and high speed. The difference in noise level is actually 3-11dB in driving sprocket speed of 1000r/min, and a significant noise reduction is achieved. The results also verify low noise characteristics of the new roller chain and rationality of design method.

scholarly journals Experimental and Numerical Study on Gas-Liquid Two-Phase Flow Behavior and Flow Induced Noise Characteristics of Radial Blade Pumps

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 920 ◽  
Author(s):  
Qiaorui Si ◽  
Chunhao Shen ◽  
Asad Ali ◽  
Rui Cao ◽  
Jianping Yuan ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Numerical Study ◽  
Flow Behavior ◽  
Internal Flow ◽  
Suction Side ◽  
Low Noise ◽  
Stable Operation ◽  
Phase Flow ◽  
Two Phase ◽  
Noise Characteristics

Miniature drainage pumps with a radial blade are widely used in situations with critical constant head and low noise requests, but the stable operation state is often broken up by the entraining gas. In order to explore the internal flow characteristics under gas–liquid two phase flow, pump performance and emitted noise measurements were processed under different working conditions. Three-dimensional numerical calculations based on the Euler inhomogeneous model and obtained experimental boundaries were carried out under different inlet air void fractions (IAVFs). A hybrid numerical method was proposed to obtain the flow-induced emitted noise characteristics. The results show there is little influence on pump characteristics when the IAVF is less than 1%. The pump head slope degradation was found to increase with air content. The bubbles adhere to the impeller hub on the blade’s suction side and spread to the periphery with a big IAVF, leading to unstable operation. It is obvious that vortices appear inside the impeller flow passage as IAVF reaches 6.5%. The two-phase flow pattern has a small effect on the characteristic frequency distribution of pressure fluctuation and emitted noise, but the corresponding pulsation intensity and noise level will increase. The study could provide some reference for low noise design of the drainage pump.

scholarly journals Application of High-Speed Quantum Cascade Detectors for Mid-Infrared, Broadband, High-Resolution Spectroscopy

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5706
Author(s):  
Tatsuo Dougakiuchi ◽  
Naota Akikusa
Keyword(s):  
High Resolution ◽  
High Speed ◽  
Dynamic Range ◽  
Molecular Spectroscopy ◽  
Low Noise ◽  
Heterodyne Detection ◽  
High Resolution Spectroscopy ◽  
Mid Infrared ◽  
Quantum Cascade ◽  
Noise Characteristics

Broadband, high-resolution, heterodyne, mid-infrared absorption spectroscopy was performed with a high-speed quantum cascade (QC) detector. By strictly reducing the device capacitance and inductance via air-bridge wiring and a small mesa structure, a 3-dB frequency response over 20 GHz was obtained for the QC detector, which had a 4.6-μm peak wavelength response. In addition to the high-speed, it exhibited low noise characteristics limited only by Johnson–Nyquist noise, bias-free operation without cooling, and photoresponse linearity over a wide dynamic range. In the detector characterization, the noise-equivalent power was 7.7 × 10−11 W/Hz1/2 at 4.6 μm, and it had good photoresponse linearity up to 250 mW, with respect to the input light power. Broadband and high-accuracy molecular spectroscopy based on heterodyne detection was demonstrated by means of two distributed-feedback 4.5-μm QC lasers. Specifically, several nitrous oxide absorption lines were acquired over a wavelength range of 0.8 cm−1 with the wide-band QC detector.

Performance improvement of a high-speed aero-fuel centrifugal pump through active inlet injector

2020 ◽  
pp. 095441002096096
Author(s):  
Jia Li ◽  
Xin Wang ◽  
Wancheng Wang ◽  
Yue Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Turbulence Model ◽  
High Speed ◽  
Flow Direction ◽  
Active Flow Control ◽  
Turbulence Models ◽  
Internal Flow ◽  
Geometrical Parameters ◽  
Centrifugal Pumps

This paper presents a high-speed aero-fuel centrifugal pump with an active inlet injector for an aero-engine aiming at regulating the internal flow field and improving overall hydraulic performance. Unlike most of the existing centrifugal pumps for aero-engines, an injector is designed and integrated with the pump to accomplish the active flow control. Firstly, by employing the energy equation in the pump, reasonable geometrical parameters of the injector are calculated. Then, a validation study is conducted with three known turbulence models, showing that simulations with the RNG κ- ε turbulence model can accurately predict the head and efficiency of the experimental pump. Finally, simulation results with the determined turbulence model are discussed. The results show that the static pressure is uniformly distributed inside the impeller, the volute and the injector. The flow field is significantly ameliorated by improving the pressure inside the suction pipe and controlling the flow direction via the injector. Furthermore, the head and efficiency of the designed pump with an active inlet injector are improved compared to the one without an injector.

Experimental Investigation of Cavity Patterns and Noise Characteristics

2016 ◽  
Author(s):  
Byoung-Kwon Ahn ◽  
So-won Jeong ◽  
Ji-Hye Kim
Keyword(s):  
High Speed ◽  
Pressure Fluctuations ◽  
Low Noise ◽  
Growth Patterns ◽  
Marine Propeller ◽  
Underwater Noise ◽  
Local Pressure ◽  
Noise Characteristics ◽  
Measured Pressure ◽  
Pressure Cavity

When a marine propeller with the wing shape rotates at high speed underwater, local pressure on the blade decreases and various types of cavitation inevitably occur in where the local pressure falls below the vapor pressure. Cavity reduces the efficiency, erodes the propeller surface, and generate vibration and serious noise. Especially, underwater noise caused by cavitation is directly connected to the comfort of commercial ships and also the survivability of naval vessels. In order to reduce the occurrence of the cavitation and to design low noise propeller, it is demanded to figure out the correlation of noise characteristics with growth patterns of the cavity. In this paper, we observed global behavior of partial cavities generated on two-dimensional hydrofoils and made a map of cavity patterns. We also measured pressure fluctuations and investigated noise characteristics directly connected with the process of occurrence of the cavity.

scholarly journals Optimization Study on a Novel High-Speed Oil-Free Centrifugal Water Pump with Hydrodynamic Bearings

2019 ◽  
Vol 9 (15) ◽  
pp. 3050 ◽  
Author(s):  
Rong Xue ◽  
Yijie Cai ◽  
Xufeng Fang ◽  
Liang Chen ◽  
Xingqun Zhang ◽  
...  
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Three Dimensional ◽  
Low Noise ◽  
Water Pump ◽  
Centrifugal Pumps ◽  
Hydrodynamic Bearings ◽  
Turbulent Fluid Flow ◽  
Blade Number ◽  
Industrial Sectors

In aerospace fields and industrial sectors, high-speed centrifugal pumps are prevalent and in increasingly strict demand regarding characteristics such as the long life, small volume, light weight, and low noise. In this study, we present a novel high-speed centrifugal water pump with hydrodynamic bearings used to employ work fluid as lubricant. A three-dimensional numerical study of the turbulent fluid flow was carried out to predict the performance of the pump. The computational model was validated against experimental results during hydraulic tests. Additionally, the effect of the blade number on the head and efficiency of the pump was researched. The blade number of the impeller was changed from 4 to 8 and that of the stay vane was from 3 to 14. The results indicate that the blade number and the matching characteristic of the impeller and the stay vane significantly influenced the performance of the pump. The structure based on the seven-blade impeller and the six-blade stay vane had the highest efficiency (30.8%). Numerical investigations of this study may help reduce the significant cost and time of experimental work for a particular design.

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