With extensively using of centrifugal pumps,noise generation in these pumps is increasingly receiving research attention in recent years.The noise sources in centrifugal pumps are mainly composed of mechanical noise a...With extensively using of centrifugal pumps,noise generation in these pumps is increasingly receiving research attention in recent years.The noise sources in centrifugal pumps are mainly composed of mechanical noise and flow-induced noise.And the study of flow-induced noise has become a hotspot and important domain in the field.The flow-induced noise closely related to the inner pressure pulses and vibration of volute in pumps,therefore,it is necessary to research the interaction and mechanism among them.To investigate the relationships,a test system is designed which includes a test loop and a measurement system.The hydrophones and pressure sensors are installed on the outlet of the pump and vibration acceleration sensors are disposed on the pump body.Via these instruments,the signals of noise,pressure pulses and vibration are collected and analyzed.The results show that the level of flow-induced noise becomes smaller as the flow increment during low flow rate operations,and it is steadily close to the design point,then it increases with the growing of flow rate in high flow rate conditions.Furthermore,there are some similar peak points in the power spectrum charts of noise,pressure pulses and vibration.The broadband noise at low flow rate is mostly focused on the region of 0-40 times shaft frequency,which is mostly made by rotating stall and vortex;while the noise at high flow rate conditions is focused on the region of 60-100 times shaft frequency,which may be mostly made by cavitations.The proposed research is of practical and academic significance to the study of noise reduction for centrifugal pumps.展开更多
Flow in pumps is essentially three-dimensional and unsteady, and it has much influence on the pump hydraulic performance and structural vibration. This paper presents a numerical methodology developed for modeling suc...Flow in pumps is essentially three-dimensional and unsteady, and it has much influence on the pump hydraulic performance and structural vibration. This paper presents a numerical methodology developed for modeling such complicated flows. Three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations, together with standard k-Ε equation, describe the unsteady-turbulent flow in the pumps. System characteristics are incorporated into the pump CFD models to allow for fluid acceleration in the piper Arbitrary Sliding Interface (ASI) is used to simulate the relative movement between the impeller and stationary components; a numerical analysis is carried out for the entire circumference to consider the asymmetrical flow physics during the stall condition. Combination of these techniques has captured the realistic unsteady flow physics in the pumps and it permits good prediction for the pump off-design performance.展开更多
The fundamental characteristics and the flow mechanism of a Vibrating Flow Pump （VFP） with a jelly-fish valve, which can be applied to a novel artificial heart, were studied theoretically and experimentally. By usin...The fundamental characteristics and the flow mechanism of a Vibrating Flow Pump （VFP） with a jelly-fish valve, which can be applied to a novel artificial heart, were studied theoretically and experimentally. By using water as the working fluid, the measurement methodology for the typical unsteady flow for VFP was developed here. The effects of the frequency, amplitude and inner diameter of the vibrating pipe, and thickness of the silicone rubber sheet of the jelly-fish valve on the basic per- formance of VFP were systematically investigated. A high-speed observation technique and simple theoretical model analysis were also introdueed for further detailed discussion. Quantitative contributions of the individual parameters to the pumping performance were shown through the experiment, which would give us essential knowledge for establishing design criteria of VFE The theoretical model, which agreed with the experiment and the high-speed observation, elucidated the pumping mechanism with respect to the role of inertia of the inner fluid.展开更多
基金supported by National Outstanding Young Scientists Founds of China (Grant No. 50825902)National Natural Science Foundation of China (Grant No. 50979034)+2 种基金Jiangsu Provincial Innovative Scholars "Climbing" Project of China (Grant No. BK2009006)Jiangsu Provincial Natural Science Foundation of China (Grant No. BK2009218)Priority Academic Program Development of Jiangsu Higher Education Institutions of China
文摘With extensively using of centrifugal pumps,noise generation in these pumps is increasingly receiving research attention in recent years.The noise sources in centrifugal pumps are mainly composed of mechanical noise and flow-induced noise.And the study of flow-induced noise has become a hotspot and important domain in the field.The flow-induced noise closely related to the inner pressure pulses and vibration of volute in pumps,therefore,it is necessary to research the interaction and mechanism among them.To investigate the relationships,a test system is designed which includes a test loop and a measurement system.The hydrophones and pressure sensors are installed on the outlet of the pump and vibration acceleration sensors are disposed on the pump body.Via these instruments,the signals of noise,pressure pulses and vibration are collected and analyzed.The results show that the level of flow-induced noise becomes smaller as the flow increment during low flow rate operations,and it is steadily close to the design point,then it increases with the growing of flow rate in high flow rate conditions.Furthermore,there are some similar peak points in the power spectrum charts of noise,pressure pulses and vibration.The broadband noise at low flow rate is mostly focused on the region of 0-40 times shaft frequency,which is mostly made by rotating stall and vortex;while the noise at high flow rate conditions is focused on the region of 60-100 times shaft frequency,which may be mostly made by cavitations.The proposed research is of practical and academic significance to the study of noise reduction for centrifugal pumps.
文摘Flow in pumps is essentially three-dimensional and unsteady, and it has much influence on the pump hydraulic performance and structural vibration. This paper presents a numerical methodology developed for modeling such complicated flows. Three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations, together with standard k-Ε equation, describe the unsteady-turbulent flow in the pumps. System characteristics are incorporated into the pump CFD models to allow for fluid acceleration in the piper Arbitrary Sliding Interface (ASI) is used to simulate the relative movement between the impeller and stationary components; a numerical analysis is carried out for the entire circumference to consider the asymmetrical flow physics during the stall condition. Combination of these techniques has captured the realistic unsteady flow physics in the pumps and it permits good prediction for the pump off-design performance.
文摘The fundamental characteristics and the flow mechanism of a Vibrating Flow Pump （VFP） with a jelly-fish valve, which can be applied to a novel artificial heart, were studied theoretically and experimentally. By using water as the working fluid, the measurement methodology for the typical unsteady flow for VFP was developed here. The effects of the frequency, amplitude and inner diameter of the vibrating pipe, and thickness of the silicone rubber sheet of the jelly-fish valve on the basic per- formance of VFP were systematically investigated. A high-speed observation technique and simple theoretical model analysis were also introdueed for further detailed discussion. Quantitative contributions of the individual parameters to the pumping performance were shown through the experiment, which would give us essential knowledge for establishing design criteria of VFE The theoretical model, which agreed with the experiment and the high-speed observation, elucidated the pumping mechanism with respect to the role of inertia of the inner fluid.
