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Magnetic Particle Imaging for Magnetic Hyperthermia Treatment: Visualization and Quantification of the Intratumoral Distribution and Temporal Change of Magnetic Nanoparticles in Vivo 被引量:5
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作者 Tomomi Kuboyabu Isamu Yabata +4 位作者 Marina Aoki Natsuo Banura Kohei Nishimoto Atsushi Mimura Kenya Murase 《Open Journal of Medical Imaging》 2016年第1期1-15,共15页
Purpose: Magnetic hyperthermia treatment (MHT) is a strategy for cancer therapy using the tem-perature rise of magnetic nanoparticles (MNPs) under an alternating magnetic field (AMF). Re-cently, a new imaging method c... Purpose: Magnetic hyperthermia treatment (MHT) is a strategy for cancer therapy using the tem-perature rise of magnetic nanoparticles (MNPs) under an alternating magnetic field (AMF). Re-cently, a new imaging method called magnetic particle imaging (MPI) has been introduced. MPI allows imaging of the spatial distribution of MNPs. The purpose of this study was to investigate the feasibility of visualizing and quantifying the intratumoral distribution and temporal change of MNPs and predicting the therapeutic effect of MHT using MPI. Materials and Methods: Colon-26 cells (1 × 106 cells) were implanted into the backs of eight-week-old male BALB/c mice. When the tumor volume reached approximately 100 mm3, mice were divided into untreated (n = 10) and treated groups (n = 27). The tumors in the treated group were directly injected with MNPs (Resovist?) with iron concentrations of 500 mM (A, n = 9), 400 mM (B, n = 8), and 250 mM (C, n = 10), respectively, and MHT was performed using an AMF with a frequency of 600 kHz and a peak amplitude of 3.5 kA/m. The mice in the treated group were scanned using our MPI scanner immediately before, immediately after, 7 days, and 14 days after MHT. We drew a region of interest (ROI) on the tumor in the MPI image and calculated the average, maximum, and total MPI values and the number of pixels by taking the threshold value for extracting the contour as 40% of the maximum MPI value (pixel value) within the ROI. These parameters in the untreated group were taken as zero. We also measured the relative tumor volume growth (RTVG) defined by (V-V0)/V0, where V0 and V are the tumor volumes immediately before and after MHT, respectively. Results: The average, maximum, and total MPI values decreased up to 7 days after MHT and remained almost constant thereafter in all groups, whereas the number of pixels tended to increase with time. The RTVG values in Groups A and B were significantly lower than those in the control group 3 days or more and 5 days or more after MHT, respectively. The above four parameters were significantly inversely correlated with the RTVG values 5, 7, and 14 days after MHT. Conclusion: MPI can visualize and quantify the intratumoral distribution and temporal change of MNPs before and after MHT. Our results suggest that MPI will be useful for predicting the therapeutic effect of MHT and for the treatment planning of MHT. 展开更多
关键词 Magnetic particle imaging Magnetic Hyperthermia Treatment Magnetic Nanoparticles Intratumoral Distribution Temporal Change
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Usefulness of Magnetic Particle Imaging for Monitoring the Effect of Magnetic Targeting 被引量:1
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作者 Tomomi Kuboyabu Akiko Ohki +1 位作者 Natsuo Banura Kenya Murase 《Open Journal of Medical Imaging》 2016年第2期33-41,共9页
Purpose: Magnetic targeting refers to the attachment of therapeutic agents to magnetizable particles such as magnetic nanoparticles (MNPs) and then applying magnetic fields to concentrate them to the targeted region s... Purpose: Magnetic targeting refers to the attachment of therapeutic agents to magnetizable particles such as magnetic nanoparticles (MNPs) and then applying magnetic fields to concentrate them to the targeted region such as solid tumors. The purpose of this study was to investigate the usefulness of magnetic particle imaging (MPI) for monitoring the effect of magnetic targeting using tumor-bearing mice. Materials and Methods: Colon-26 cells (1 × 106 cells) were implanted into the backs of eight-week-old male BALB/c mice. When the tumor volume reached approximately 100 mm3, the mice were divided into treated (n = 8) and untreated groups (n = 8). The tumors in the treated group were directly injected with MNPs (Resovist?, 250 mM) and a neodymium magnet was attached to the tumor surface, whereas the magnet was not attached to the tumor in the untreated group. The mice were imaged using our MPI scanner and the average and maximum MPI values were obtained by drawing a region of interest (ROI) on the tumor, with the threshold value for extracting the contour of the tumor being taken as 40% of the maximum MPI value in the ROI. The relative tumor volume growth (RTVG) was calculated from (V ? V0)/V0, where V0 and V represented the tumor volume immediately before and after the injection of MNPs, respectively. Results: The average and maximum MPI values in the treated group were significantly higher than those in the untreated group 3 days after the injection of MNPs, suggesting the effectiveness of magnetic targeting. There were no significant differences in RTVG between the two groups. Conclusion: Our preliminary results suggest that MPI is useful for monitoring the effect of magnetic targeting. 展开更多
关键词 Magnetic particle imaging Magnetic Targeting Magnetic Nanoparticles Tumor-Bearing Mice
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Recent developments of the reconstruction in magnetic particle imaging
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作者 Lin Yin Wei Li +4 位作者 Yang Du Kun Wang Zhenyu Liu Hui Hui Jie Tian 《Visual Computing for Industry,Biomedicine,and Art》 EI 2022年第1期290-302,共13页
Magnetic particle imaging(MPI)is an emerging molecular imaging technique with high sensitivity and temporal-spatial resolution.Image reconstruction is an important research topic in MPI,which converts an induced volta... Magnetic particle imaging(MPI)is an emerging molecular imaging technique with high sensitivity and temporal-spatial resolution.Image reconstruction is an important research topic in MPI,which converts an induced voltage signal into the image of superparamagnetic iron oxide particles concentration distribution.MPI reconstruction primarily involves system matrix-and x-space-based methods.In this review,we provide a detailed overview of the research status and future research trends of these two methods.In addition,we review the application of deep learning methods in MPI reconstruction and the current open sources of MPI.Finally,research opinions on MPI reconstruction are presented.We hope this review promotes the use of MPI in clinical applications. 展开更多
关键词 Magnetic particle imaging Image reconstruction System matrix X-space
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Mass transfer enhancement and hydrodynamic performance with wire mesh coupling solid particles in bubble column reactor
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作者 Chuanjun Di Jipeng Dong +3 位作者 Fei Gao Guanghui Chen Pan Zhang Jianlong Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期195-205,共11页
It is of vital significance to investigate mass transfer enhancements for chemical engineering processes.This work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on b... It is of vital significance to investigate mass transfer enhancements for chemical engineering processes.This work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on bubble motion and gas-liquid mass transfer process in a bubble column.Particle image velocimetry(PIV)technology was employed to analyze the flow field and bubble motion behavior,and dynamic oxygen absorption technology was used to measure the gas-liquid volumetric mass transfer coefficient(kLa).The effect of embedding wire mesh,adding solid particles,and wire mesh coupling solid particles on the flow characteristic and kLa were analyzed and compared.The results show that the gas-liquid interface area increases by 33%-72%when using the wire mesh coupling solid particles strategy compared to the gas-liquid two-phase flow,which is superior to the other two strengthening methods.Compared with the system without reinforcement,kLa in the bubble column increased by 0.5-1.8 times with wire mesh coupling solid particles method,which is higher than the sum of kLa increases with inserting wire mesh and adding particles,and the coupling reinforcement mechanism for affecting gas-liquid mass transfer process was discussed to provide a new idea for enhancing gas-liquid mass transfer. 展开更多
关键词 Fluid mechanics BUBBLE Mass transfer Wire mesh coupling solid particles particle image velocimetry Hydrodynamics
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Monitoring shear deformation of sliding zone via fiber Bragg grating and particle image velocimetry
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作者 Deyang Wang Honghu Zhu +3 位作者 Guyu Zhou Wenzhao Yu Baojun Wang Wanhuan Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期231-241,共11页
Monitoring shear deformation of sliding zones is of great significance for understanding the landslide evolution mechanism,in which fiber optic strain sensing has shown great potential.However,the cor-relation between... Monitoring shear deformation of sliding zones is of great significance for understanding the landslide evolution mechanism,in which fiber optic strain sensing has shown great potential.However,the cor-relation between strain measurements of quasi-distributed fiber Bragg grating(FBG)sensing arrays and shear displacements of surrounding soil remains elusive.In this study,a direct shear model test was conducted to simulate the shear deformation of sliding zones,in which the soil internal deformation was captured using FBG strain sensors and the soil surface deformation was measured by particle image velocimetry(PIV).The test results show that there were two main slip surfaces and two secondary ones,developing a spindle-shaped shear band in the soil.The formation of the shear band was successfully captured by FBG sensors.A sinusoidal model was proposed to describe the fiber optic cable deformation behavior.On this basis,the shear displacements and shear band widths were calculated by using strain measurements.This work provides important insight into the deduction of soil shear deformation using soil-embedded FBG strain sensors. 展开更多
关键词 LANDSLIDE Shear band Fiber bragg grating(FBG) particle image velocimetry(PIV) Sinusoidal model Strain‒displacement proportional COEFFICIENT
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Significance of including lid thickness and particle shape factor in numerical modeling for prediction of particle trap efficiency of invert trap
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作者 Salman Beg Deo Raj Kaushal 《Water Science and Engineering》 EI CAS CSCD 2024年第2期166-176,共11页
Sediment accumulation on the bed of open sewers and drains reduces hydraulic efficiency and can cause localized flooding.Slotted invert traps installed underneath the bed of open sewers and drains can eliminate sedime... Sediment accumulation on the bed of open sewers and drains reduces hydraulic efficiency and can cause localized flooding.Slotted invert traps installed underneath the bed of open sewers and drains can eliminate sediment build-up by catching sediment load.Previous three-dimensional(3D)computational studies have examined the particle trapping performance of invert traps of different shapes and depths under varied sediment and flow conditions,considering particles as spheres.For two-dimensional and 3D numerical modeling,researchers assumed the lid geometry to be a thin line and a plane,respectively.In this 3D numerical study,the particle trapping efficiency of a slotted irregular hexagonal invert trap fitted at the flume bottom was examined by incorporating the particle shape factor of non-spherical sewage solid particles and the thicknesses of upstream and downstream lids over the trap in the discrete phase model of the ANSYS Fluent 2020 R1 software.The volume of fluid(VOF)and the realizable k-turbulence models were used to predict the velocity field.The two-dimensional particle image velocimetry(PIV)was used to measure the velocity field inside the invert trap.The results showed that the thicknesses of upstream and downstream lids affected the velocity field and turbulent kinetic energy at all flow depths.The joint impact of the particle shape factor and lid thickness on the trap efficiency was significant.When both the lid thickness and particle shape factor were considered in the numerical modeling,trap efficiencies were underestimated,with relative errors of-8.66%to-0.65%in comparison to the experimental values of Mohsin and Kaushal(2017).They were also lower than the values predicted by Mohsin and Kaushal(2017),which showed an overall overestimation with errors of-2.3%to 17.4%. 展开更多
关键词 Invert trap Lid thickness particle image velocimetry particle shape factor Turbulent kinetic energy Scanning electron microscope
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Inclusion of the tunneling phase shift for interferometric particle imaging for bubble sizing 被引量:1
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作者 Xiang Liu Jianqi Shen +1 位作者 Peng Gong Haitao Yu 《Particuology》 SCIE EI CAS CSCD 2021年第1期50-57,共8页
The interferometric particle imaging technique makes use of the angular oscillations of the scattered light in the forward direction for droplet or bubble sizing.The out-of-focus image consists of fringes,the spacing ... The interferometric particle imaging technique makes use of the angular oscillations of the scattered light in the forward direction for droplet or bubble sizing.The out-of-focus image consists of fringes,the spacing of which reflects the interference between the surface-reflected light and the twofold-refracted light.Total internal reflection occurs when the incident light hits the bubble at a large incident angle.The tunneling phase shift is not included in the geometric optics approximation,which leads to a deviation from Mie theory.In this work,we modified the formula for describing the fringe spacing by including the tunneling phase shift of total internal reflection.Numerical analysis and experiments showed that the modification is effective for the measurement of bubbles smaller than 60μm. 展开更多
关键词 Interferometric particle imaging BUBBLES Total internal reflection Tunneling phase shift
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Advances in magnetic particle imaging and perspectives on liver imaging
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作者 Wei Li Xiaohua Jia +6 位作者 Lin Yin Zhiyun Yang Hui Hui Jianlin Li Wenhui Huang Jie Tian Shuixing Zhang 《iLIVER》 2022年第4期237-244,共8页
Magnetic particle imaging(MPI)is an emerging technique to visualize the spatial distribution of super-paramagnetic iron oxide with high temporal–spatial resolution,high sensitivity,unlimited image depth,and true quan... Magnetic particle imaging(MPI)is an emerging technique to visualize the spatial distribution of super-paramagnetic iron oxide with high temporal–spatial resolution,high sensitivity,unlimited image depth,and true quantitative information.MPI is based on the nonlinear response of superparamagnetic iron oxide in an alter-nating magnetic field without tissue background noise.It is a promising imaging modality for various applica-tions,including vascular imaging,cell tracking,tumor imaging,and catheter navigation.Many applications of liver imaging could be improved or created with MPI.In this review,we cover the principle and construction of MPI,we evaluate the features and advantages of MPI with relation to its own rationale and via comparison with other imaging modalities,and we review MPI liver imaging applications with a view toward assisting hepatic researchers in drawing inspiration. 展开更多
关键词 Magnetic particle imaging Liver imaging SPIO
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Three-dimensional color particle image velocimetry based on a cross-correlation and optical flow method
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作者 单良 熊俊哲 +4 位作者 施飞杨 洪波 简娟 詹虹晖 孔明 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第5期88-96,共9页
Rainbow particle image velocimetry(PIV)can restore the three-dimensional velocity field of particles with a single camera;however,it requires a relatively long time to complete the reconstruction.This paper proposes a... Rainbow particle image velocimetry(PIV)can restore the three-dimensional velocity field of particles with a single camera;however,it requires a relatively long time to complete the reconstruction.This paper proposes a hybrid algorithm that combines the fast Fourier transform(FFT)based co-correlation algorithm and the Horn–Schunck(HS)optical flow pyramid iterative algorithm to increase the reconstruction speed.The Rankine vortex simulation experiment was performed,in which the particle velocity field was reconstructed using the proposed algorithm and the rainbow PIV method.The average endpoint error and average angular error of the proposed algorithm were roughly the same as those of the rainbow PIV algorithm;nevertheless,the reconstruction time was 20%shorter.Furthermore,the effect of velocity magnitude and particle density on the reconstruction results was analyzed.In the end,the performance of the proposed algorithm was verified using real experimental single-vortex and double-vortex datasets,from which a similar particle velocity field was obtained compared with the rainbow PIV algorithm.The results show that the reconstruction speed of the proposed hybrid algorithm is approximately 25%faster than that of the rainbow PIV algorithm. 展开更多
关键词 particle image velocimetry color light cross-correlation and optical flow method VORTEX
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Measurement of Concentration of Sorbent Particles and Water Droplets in Hydration Desulfurization Reactor with PIV
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作者 赵长遂 吴树志 +3 位作者 刘现卓 肖军 陆勇 王式民 《Journal of Southeast University(English Edition)》 EI CAS 2002年第1期88-91,共4页
Vortexing limestone injection into furnace combined with calcium lime hydration in the downstream is the most promising technology for controlling SO 2 emission. Particle imaging velocimetry (PIV) is used to measure ... Vortexing limestone injection into furnace combined with calcium lime hydration in the downstream is the most promising technology for controlling SO 2 emission. Particle imaging velocimetry (PIV) is used to measure the gas liquid solid three phase flow field in a reactor. By image processing based on newly developed software, the number concentrations of sorbent particles and water droplets are presented. The measuring results are very helpful for better understanding the desulfurization mechanism and optimizing configurational and operational parameters in the hydration reactor. 展开更多
关键词 particle image velocimetry DESULFURIZATION particle water droplet CONCENTRATION
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Study of Diesel Spray Particle Velocity Field Using a Particle Image Velocimetry Setup
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作者 郝利君 刘福水 +1 位作者 刘玉林 孙济美 《Journal of Beijing Institute of Technology》 EI CAS 1999年第2期90-95,共6页
Aim To investigate the spray particle velocity and its distribution characteristics. Methods\ A set of PIV (particle image velocimetry) system was developed and used to observe and analyze the spray particle velocity... Aim To investigate the spray particle velocity and its distribution characteristics. Methods\ A set of PIV (particle image velocimetry) system was developed and used to observe and analyze the spray particle velocity field. Results and Conclusion\ Double exposure image of the spray particle within the region of 10-50 mm from the nozzle tip was recorded and analyzed by the IBAS2000 analysis system. Some characteristics of the spray particle velocity and its distribution were obtained. 展开更多
关键词 PIV (particle image velocimetry) diesel engine SPRAY velocity characteristics
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Analysis of rotor eddy current loss and thermal deformation of magnetic liquid double suspension bearing
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作者 LIU Hongmei YANG Guang +3 位作者 SUN Yanan SUN Jian WANG Zhe ZHAO Jianhua 《High Technology Letters》 EI CAS 2024年第3期322-332,共11页
Magnetic-liquid double suspension bearing(MLDSB)is a new type of suspension bearing based on electromagnetic suspension and supplemented by hydrostatic supporting.Without affecting the electromagnetic suspension force... Magnetic-liquid double suspension bearing(MLDSB)is a new type of suspension bearing based on electromagnetic suspension and supplemented by hydrostatic supporting.Without affecting the electromagnetic suspension force,the hydrostatic supporting effect is increased,and the real-time coupling of magnetic and liquid supporting can be realized.However,due to the high rotation speed,the rotor part produces eddy current loss,resulting in a large temperature rise and large ther-mal deformation,which makes the oil film thickness deviate from the initial design.The support and bearing characteristics are seriously affected.Therefore,this paper intends to explore the internal effects of eddy current loss of the rotor on the temperature rise and thermal deformation of MLDSB.Firstly,the 2D magnetic flow coupling mathematical model of MLDSB is established,and the eddy current loss distribution characteristics of the rotor are numerically simulated by Maxwell software.Secondly,the internal influence of mapping relationship of structural operating parameters such as input current,coil turns and rotor speed on rotor eddy current loss is revealed,and the changing trend of rotor eddy current loss under different design parameters is explored.Thirdly,the eddy cur-rent loss is loaded into the heat transfer finite element calculation model as a heat source,and the temperature rise of the rotor and its thermal deformation are simulated and analyzed,and the influ-ence of eddy current loss on rotor temperature rise and thermal deformation is revealed.Finally,the pressure-flow curve and the distribution law of the internal flow field are tested by the particle image velocimetry(PIV)system.The results show that eddy current loss increases linearly with the in-crease of coil current,coil turns and rotor speed.The effect of rotational speed on eddy current loss is much higher than that of coil current and coil turns.The maximum temperature rise,minimum temperature rise and maximum thermal deformation of the rotor increase with the increase of eddy current loss.The test results of flow-pressure and internal trace curves are basically consistent with the theoretical simulation,which effectively verifies the correctness of the theoretical simulation.The research results can provide theoretical basis for the design and safe and stable operation of magnetic fluid double suspension bearings. 展开更多
关键词 magnetic-liquid double suspension bearing(MLDSB) oil film thickness cur-rent loss thermal deformation particle image velocimetry(PIV)test
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Particle image velocimetry and numerical simulations of the hydrodynamic characteristics of an artificial reef 被引量:14
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作者 姜昭阳 梁振林 +2 位作者 刘扬 唐衍力 黄六一 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第5期949-956,共8页
This article reports a particle image velocimetry study and the comparative results of a numerical simulation into the hydrodynamic characteristics around an artificial reef.We reveal the process of flow separation an... This article reports a particle image velocimetry study and the comparative results of a numerical simulation into the hydrodynamic characteristics around an artificial reef.We reveal the process of flow separation and vortex evolution,and compare the force terms generated by our artificial reef model.The numerical simulation agrees well with experimental results,showing the applicability of computational fluid dynamics to the hydrodynamics of an artificial reef.Furthermore,we numerically simulate the hydrodynamics of the reef model for seven velocities.The results show that the drag coefficient is approximately 1.21 in a self-modeling region for Reynolds numbers between 2.123×104and 9×104.Therefore,the upwelling height and current width of the flow field do not change significantly when the inflow velocity increases.Our study indicates that computational fluid dynamics can be applied to study the hydrodynamics of an artificial reef and offer clues to its construction. 展开更多
关键词 artificial reef model particle image velocimetry (PIV) flow field hydrodynamic force self-modeling region
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Investigation of Fluid Flow in a Dual Rushton Impeller Stirred Tank Using Particle Image Velocimetry 被引量:13
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作者 潘春妹 闵健 +1 位作者 刘心洪 高正明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第5期693-699,共7页
The flow fields in a dual Rushton impeller stirred tank with diameter of 0.48 m (T) were measured by using Particle Image Velocimetry (PIV). Three different size impellers were used in the experiments with diamete... The flow fields in a dual Rushton impeller stirred tank with diameter of 0.48 m (T) were measured by using Particle Image Velocimetry (PIV). Three different size impellers were used in the experiments with diameters of D = 0.33T, 0.40T and 0.50T, respectively. The multi-block and 360° ensemble-averaged approaches were used to measure the radial and axial angle-resolved velocity distributions. Three typical flow patterns, named, merging flow, parallel flow and diverging flow, were obtained by changing the clearance of the bottom impeller above the tank base (C1) and the spacing between the two impellers (C2). The results show that while C1 is equal to D, the parallel flow occurs as C2≥0.40T, C2≥0.38T and C2≥0.32T and the merging flow occurs as C2≤0.38T, C2≤0.36T and C2≤0.27T for the impellers with diameter of D=0.33T, 0.40T and 0.50T, respectively. When C2 is equal to D, the diverging flow occurs in the value of C1≤0.15T for all three impellers. The flow numbers of these impellers were calculated for the parallel flow. Trailing vortices generated by the lower impeller for the diverging flow were shown by the 10° angle-resolved velocity measurements. The peak value of turbulence kinetic energy ( k/V^2tip = 0.12-0.15 or above) appears along the center of the impeller discharging stream. 展开更多
关键词 particle image velocimetry dual Rushton flow field flow pattern
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Particle Image Velocimetry Study of Turbulence Characteristics in a Vessel Agitated by a Dual Rushton Impeller 被引量:12
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作者 刘心洪 包雨云 +2 位作者 李志鹏 高正明 John M. Smith 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第5期700-708,共9页
Particle Image Velocimetry (PIV) has been used to investigate turbulence characteristics in a 0.48 m diameter stirred vessel filled to a liquid height ( H = 1.4T ) of 0.67 m. The agitator had dual Rushton impeller... Particle Image Velocimetry (PIV) has been used to investigate turbulence characteristics in a 0.48 m diameter stirred vessel filled to a liquid height ( H = 1.4T ) of 0.67 m. The agitator had dual Rushton impellers of 0.19 m diameter ( D = 0.4T ). The developed flow patterns depend on the clearance of the lower impeller above the base of the vessel, the spacing between the two impellers, and the submergence of the upper impeller below the liq- uid surface. Their combinations can generate three basic flow patterns, named, parallel, merging and diverging flows. The results of velocity measurement show that the flow characteristics in the impeller jet flow region changes very little for different positions. Average velocity, trailing vortices and shear strain rate distributions for three flow patterns were measured by using PIV technique. The characteristics of trailing vortex and its trajectory were described in detail for those three flow patterns. Since the space-resolution of PIV can only reach the sub-grid rather than the Kolmogorov scale, a large-eddy PIV analysis has been used to estimate the distribution of the turbulent kinetic energy dissipation. Comparison of the distributions of turbulent kinetic energy and dissipation rate in merging flow shows that the highest turbulent kinetic energy and dissipation are both located in the vortex regions, but the maxima are at somewhat different lo- cations behind the blade. About 37% of the total energy is dissipated in dual impeller jet flow regions. The obtained distribution of shear strain rate for merging flow is similar to that of turbulence dissipation, with the shear strain rate around the trailing vortices much higher than in other areas. 展开更多
关键词 dual Rushton impeller flow pattern large-eddy particle image velocimetry trailing vortex kinetic energy dissipation rate
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Stereo particle image velocimetry measurement of 3D soil deformation around laterally loaded pile in sand 被引量:6
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作者 袁炳祥 谌文武 +2 位作者 姜彤 汪亦显 陈科平 《Journal of Central South University》 SCIE EI CAS 2013年第3期791-798,共8页
A developed stereo particle image velocimetry(stereo-PIV) system was proposed to measure three-dimensional(3D) soil deformation around a laterally loaded pile in sand.The stereo-PIV technique extended 2D measurement t... A developed stereo particle image velocimetry(stereo-PIV) system was proposed to measure three-dimensional(3D) soil deformation around a laterally loaded pile in sand.The stereo-PIV technique extended 2D measurement to 3D based on a binocular vision model,where two cameras with a well geometrical setting were utilized to image the same object simultaneously.This system utilized two open software packages and some simple programs in MATLAB,which can easily be adjusted to meet user needs at a low cost.The failure planes form an angle with the horizontal line,which are measured at 27°-29°,approximately three-fourths of the frictional angle of soil.The edge of the strain wedge formed in front of the pile is an arc,which is slightly different from the straight line reported in the literature.The active and passive influence zones are about twice and six times of the diameter of the pile,respectively.The test demonstrates the good performance and feasibility of this stereo-PIV system for more advanced geotechnical testing. 展开更多
关键词 particle image velocimetry digital image correlation stereo particle image velocimetry laterally loaded pile scaledmodel 3D soil deformation soil-structural interaction
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Flow Field Around Rushton Turbine in Stirred Tank by Particle Image Velocimetry Measurement 被引量:7
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作者 高殿荣 ACHARYA Sumanta +1 位作者 王益群 UHM Jongho 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第6期843-850,共8页
In this paper, particle image velocimetry (PIV) was used to measure the mean and root meansquare(RMS) velocity in the stirred tank with six-flat blade Rushton turbine and with no baffles. Two typesof motion patterns w... In this paper, particle image velocimetry (PIV) was used to measure the mean and root meansquare(RMS) velocity in the stirred tank with six-flat blade Rushton turbine and with no baffles. Two typesof motion patterns were studied. One was that the impeller runs at constant speed, the other was that the impellerruns at time-dependent speed and in a periodic way. The emphasis of the paper was on the comparison of meanand RMS velocity vector maps and profiles between these two types of motion patterns, and especial attention waspaid to the comparison of the mean velocity, time-averaged RMS velocity, phase averaged RMS velocity betweenthe constant 3 RPS (revolution per second) and time-dependent operation. The Reynolds number was between 763and 1527. The study explained the mechanism that time-dependent RPS is more efficient for mixing than that ofconstant RPS. 展开更多
关键词 particle image velocimetry mean velocity stirred tank root mean squarevelocity time-dependent speed
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Particle Image Velocimetry Measurement of the Flow Field in the Play of the Drilling Pump Valve 被引量:7
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作者 YANG Guoan YIN Xin +1 位作者 SONG Zheng HUANG Cong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第1期27-37,共11页
The failure of a drilling pump is always due to the break of the drilling pump valve, which is one of the most important but also the weakest parts of the drilling pump. Over the decades, the degradation of drilling p... The failure of a drilling pump is always due to the break of the drilling pump valve, which is one of the most important but also the weakest parts of the drilling pump. Over the decades, the degradation of drilling pump valves has been investigated extensively and various failure mechanisms have been proposed. However, no experimental test on the fluid has been successfully performed to support some of these mechanisms. In this paper, tests of the flow within the valve play are carried out to investigate the factors resulting in the failure of the valve. In the tests, particle image velocimetry(PIV) technology is employed to measure the flow field distribution of the valve play in the model. From these tests, the distributions of velocity and vorticity of fluid in 'various valves with different valve angles and different valve lifts are obtained, from which the features of flow fields are derived and generalized. Subsequently, a general rule of the influence of valve angles and valve lifts on the flow velocity is concluded according to chart analyses of maximal velocities and mean velocities. Finally, an analysis is made on the possibility of valve failure caused by erosion and abrasion in a working valve, with the application of the failure mechanisms of drilling pump valves. PIV measurement improves the study on the failure of the drilling pump valve, and the results show good agreement with previous computational fluid dynamics(CFD) simulations. 展开更多
关键词 drilling pump valve flow field particle image velocimetry(PIV) valve failure
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Study on local topology model of low/high streak structures in wall-bounded turbulence by tomographic time-resolved particle image velocimetry 被引量:6
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作者 Haiping TIAN Nan JIANG +1 位作者 Yongxiang HUANG Shaoqiong YANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第9期1121-1130,共10页
The relationship between the in the logarithmic law (log-law) region of bursting event and the low/high-speed streak a turbulent boundary layer is investigated. A tomographic time-resolved particle image velocimetry... The relationship between the in the logarithmic law (log-law) region of bursting event and the low/high-speed streak a turbulent boundary layer is investigated. A tomographic time-resolved particle image velocimetry (TRPIV) system is used to measure the instantaneous three-dimensional-three-component (3D-3C) velocity field. The momentum thickness based Reynolds number is about 2 460. The topological information in the log-law region is obtained experimentally. It is found that the existence of the quadrupole topological structure implies a three-pair hairpin-like vortex packet, which is in connection with the low/high-speed streak. An idealized 3D topological model is then proposed to characterize the observed hairpin vortex packet and low/high-speed streak. 展开更多
关键词 wall turbulence quadrupole topological structure hairpin vortex low/highspeed streak tomographic time-resolved particle image velocimetry (TRPIV) system
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Particle image velocimetry (PIV) measurements of tip vortex wake structure of wind turbine 被引量:6
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作者 肖京平 武杰 +1 位作者 陈立 史喆羽 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第6期729-738,共10页
Large-view flow field measurements using the particle image velocimetry (PIV) technique with high resolution CCD cameras on a rotating 1/8 scale blade model of the NREL UAE phase VI wind turbine are conducted in the... Large-view flow field measurements using the particle image velocimetry (PIV) technique with high resolution CCD cameras on a rotating 1/8 scale blade model of the NREL UAE phase VI wind turbine are conducted in the engineering-oriented q53.2 m wind tunnel. The motivation is to establish the database of the initiation and development of the tip vortex to study the flow structure and mechanism of the wind turbine. The results show that the tip vortex first moves inward for a very short period and then moves outward with the wake expansion, while its vorticity decreases with time after being trailed from the trailing edge of the blade tip, and then increases continuously with the rapid rolling-up to form a strong tip vortex. The measurements also indicate that the downstream movement of the tip vortex is nearly linear in the very near wake under the test condition. 展开更多
关键词 wind turbine particle image velocimetry (PIV) tip vortex flow field
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