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Vibration analysis of FG annular sector in moderately thick plates with two piezoelectric layers

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Applied Mathematics and Mechanics(English Edition) 2019年第6期40卷 783-804页

作者： S.AZARIPOUR M.BAGHANI School of Mechanical Engineering College of Engineering University of Tehran

Free vibration of functionally graded (FG) annular sector plates embedded with two piezoelectric layers is studied with a generalized differential quadrature (GDQ) method. Based on the first-order shear deformation (FSD) plate theory and Hamilton’s principle with parameters satisfying Maxwell’s electrostatics equation in the piezoelectric layers, governing equations of motion are developed. Both open and closed circuit (shortly connected) boundary conditions on the piezoelectric surfaces, which are respective conditions for sensors and actuators, are accounted for. It is observed that the open circuit condition gives higher natural frequencies than a shortly connected condition. For the simulation of the potential electric function in piezoelectric layers, a sinusoidal function in the transverse direction is considered. It is assumed that properties of the FG material (FGM) change continuously through the thickness according to a power distribution law. The fast rate convergence and accuracy of the GDQ method with a small number of grid points are demonstrated through some numerical examples. With various combinations of free, clamped, and simply supported boundary conditions, the effects of the thicknesses of piezoelectric layers and host plate, power law index of FGMs, and plate geometrical parameters (e.g., angle and radii of annular sector) on the in-plane and out-of-plane nat-ural frequencies for different FG and piezoelectric materials are also studied. Results can be used to predict the behaviors of FG and piezoelectric materials in mechanical systems.

关键词： free vibration annular sector piezoelectric functionally graded material (FGM) first-order shear deformation (FSD)

Cavitation performance of high-speed centrifugal pump with annular jet and inducer at different temperatures and void fractions

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Journal of Hydrodynamics 2019年第1期31卷 93-101页

作者： Jin Jiang Yan-hui Li Chong-yan Pei Lin-lin Li You Fu Hong-gui Cheng Qiang-qiang Sun Key Laboratory of Hydraulic Machinery Transient MOEWuhan UniversityWuhan 430072China Science and Technology on Scramjet Laboratoty The 31st Research Institute of CASICBeijing 100074China

The cavitation is very common in a centrifugal pump,especially when the speed is very high,and it seriously influences the centrifugal pump performance.In this investigation,the RNG k-ε turbulence model and the cavitation model with consideration of the mass transferring are first used to simulate the cavitation performance of the high-speed centrifugal pump without taking any measure for improving the pump cavitation performance.The calculation results reveal that a number of bubbles appear in the centrifugal pump flow channel,and the head as well as the flow rate of the high-speed centrifugal pump are far from its design condition.The cavitation performance can be improved effectively by arranging a variable pitch inducer and adopting an annular nozzle scheme.The flow field analysis of the pump is conducted to obtain the suitable working temperature distribution at different void fractions.On one hand,with the same void fraction,the head of the centrifugal pump drops slowly with the increase of temperature.However,when the temperature exceeds 90°C,the head of the pump drops rapidly.On the other hand,at the constant temperature,the higher the void fraction,the worse the cavitation performance.This research conducted under different temperatures and void fractions provides some guidance for designing an effective high-speed centrifugal pump.

关键词： High-speed centrifugal pump cavitation performance inducer annular nozzle void fraction

Discretization of annular-ring diffraction pattern for large-scale photonics beamforming

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Photonics Research 2022年第5期10卷 1177-1186页

作者： AROUTIN KHACHATURIAN REZA FATEMI ARTSROUN DARBINIAN ALI HAJIMIRI California Institute of Technology PasadenaCalifornia 91125USA

A solid-state active beamformer based on the annular-ring diffraction pattern is demonstrated in an integrated photonic platform.Such a circularly symmetric annular-ring aperture achieves a radiating element limited field of view.Furthermore,it is demonstrated that a multi-annular-ring aperture with a fixed linear density of elements maintains the beam efficiency for larger apertures while reducing the beamwidth and side-lobe level.A 255-element multi-annular-ring optical phased array with active beamforming is implemented in a standard photonics process.A total of 510 phase and amplitude modulators enable beamforming and beam steering using this aperture.A row-column drive methodology reduces the required electrical drivers by more than a factor of 5.

关键词： process annular beam

LDV measurements of particle velocity distribution in an annular stripper

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Chinese Journal of Chemical Engineering 2019年第10期27卷 2293-2303页

作者： Yongzheng Li Xiaolai Zhang Guangwei Zhai Haitao Zhang Tao Li Qiwen Sun Weiyong Ying Engineering Research Center of Large Scale Reactor Engineering and Technology Ministry of EducationState Key Laboratory of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Chemical Engineering Shandong UniversityJinan 250100China State Key Laboratory of Coal Liquefaction and Coal Chemical Technology Shanghai 201203China

Particle descent velocities in an annular stripper were measured by a laser Doppler velocimetry(LDV)system.In the radial direction,particle descent velocity was relatively constant in the mid-region of the stripper and increased towards the walls on both sides,exhibiting an anti-U-shaped distribution.Particle descent velocity in the radial mid-region increased with the increase of superficial gas velocity,and the maximum in the outer wall region increased significantly with the increase of solid mass flux.Superficial stripping gas velocity had stronger effect on particle velocity distributions near the stripper gas distributor,and such effect weakened with the increase of the distance from the distributor.Local particle velocity and its radial profiles could be adjusted by changing the superficial stripping gas velocity.Empirical formulas were established to describe the relationships between the local particle velocity and cross-sectional averaged velocity based on the effects of operating conditions and measuring positions.The result showed that the predicted data was in good agreement with the experimental value.

关键词： annular stripper Flow Hydrodynamics Particle velocity Laser Doppler velocimeter

Bore-center annular shaped charges with different liner materials penetrating into steel targets

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Defence Technology（防务技术） 2019年第5期15卷 796-801页

作者： Wen-long Xu Cheng Wang Jian-ming Yuan Tao Deng State Key Lab of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Temasek Laboratories Nanyang Technological University50 Nanyang Drive637553Singapore

The bore-center annular shaped charge(BCASC)is a new type of shaped charge which can generate a larger-diameter hole in steel targets than classical shaped charges.In this paper,the influence of three liner materials,i.***.molybdenum,nickel and copper,on BCASC formation and penetrating into steel targets was investigated by experiment and numerical simulation.The simulation results were well consistent with the experimental results.This study showed that,at 0.50D standoff distance,the axial velocity of the molybdenum projectile was lower than that of the nickel and copper projectiles.The nickel and copper projectiles had almost the same head velocity.The absolute values of the radial velocity of the molybdenum projectile head was lower than that of the nickel and copper projectiles.However,at 0.75D standoff distance,the absolute values of the radial velocity of the molybdenum projectile head became much greater than that of the nickel and copper projectile heads.The projectile formed by BCASC with the molybdenum liner had the highest penetration depth of 61.5 mm,which was 10.0%and 21.3%higher than that generated by the copper and nickel projectiles.

关键词： annular shaped charge Liner material Formation Numerical simulation

INTERNALIZATION OF GAP JUNCTIONS BETWEEN NEURON AND GLIAL CELL AND FORMATION OF annular LAMELLAR BODIES IN CHINESE LEECH Whitmania pigra

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Science China Chemistry 1991年第7期34卷 840-849页

作者：朱丽霞张人骥 Department of Biology Peking University Beijing 100871 PRC

This paper reveals the formation of annular lamellar body (ALB) in the ganglion of leech by means of in situ fixation and the lanthanum nitrate tracer technique. This formation involves both wrapping and internalization of the gap junctions between glial processes themselves, as well as between neuron and glial process. The results indicate that there is probably an active process of internalization of membrane structures involving gap junctions between neuron and glial cell in the central nervous system in leech. The functions of ALB are discussed.

关键词： leech gap junction of neuron-glia internalization annular lamellar body (ALB) trophospongium.

Fast Photoacoustic Imaging of Blood Vessels Based on an annular Transducer Array

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Chinese Physics Letters 2012年第10期29卷 85-88页

作者：杨迪武曾吕明纪轩荣黄仲陈星辉谭志 Department of Physics and Engineering Hunan University of TechnologyZhuzhou 412000 Key Lab of Optic-Electronic and Communication Jiangxi Sciences and Technology Normal CollegeNanchang 330038 Doppler Electronic Technologies Company Ltd. Guangzhou 510663

We present a photoacoustic imaging system for rapid high-resolution photoacoustic imaging of blood vessels based on an annular transducer array.The annular transducer array consists of 256 elements arranged along a 300°arc with a 50-mm radius of curvature,using piezocomposite technology for high sensitivity and high signal-to-noise ratio.An eight-channel data acquisition system is applied to capture the photoacoustic signals using multiplexing and a limited-view filtered back projection algorithm is used to reconstruct the photoacoustic images.The experiments with phantom and blood vessels of a chicken are performed and clear photoacoustic images are obtained.The results demonstrate that the photoacoustic imaging system using the annular transducer array holds the potential application in monitoring neovascularization in tumor angiogenesis.

关键词： Transducer annular Blood

Firm embedding behavior of annular grooved projectiles impacting ductile metal targets

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Defence Technology（防务技术） 2019年第5期15卷 768-778页

作者： Qi Huang Shun-shan Feng Xu-ke Lan Chao-nan Chen Yong-xiang Dong Tong Zhou State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

annular grooved projectiles(AGPs)have drawn ongoing concerns as an advanced penetrator for their excellent anti-rebound capability in impacting metal plates.They could become embedded solidly in the target surface during low-velocity impact.In this investigation,the firm embedding behavior of AGP was observed by impact experiments.Corresponding numerical simulations provided a better understanding of this process.Experimental and numerical results indicated that the firm embedding behavior of AGP was mainly due to the filling-material in the groove rather than the friction between the projectile and target,unlike traditional shape such as conical projectile.According to observation,firm embedding process can generally be subdivided into four stages:initial-cratering stage,groove-filling stage,fillingmaterial failure stage and rebound vibration stage.Moreover,the damage mechanics of target material around crater was obtained through microscopic tests.A comparison of the cross-sectional figures between the experiment and simulation proved that the analysis and the proposed method were reasonable and feasible,which further demonstrated that the firm embedding behavior has application potential in new concept warheads.

关键词： annular grooved projectile (AGP) Impact Firm embedding behavior Flow characteristics Microscopic tests

SEPARATION　CHARACTERISTICS　OF　THE　HYDROCYCLONE　WITH　A　CENTRAL　CONE　AND　annular　TEETH

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中国有色金属学会会刊：英文版 1996年第4期6卷 11-15页

作者： Chu, LY Chen, WM Luo, Q NORTHEASTERN UNIV DEPT MINERAL ENGN SHENYANG 110006 PEOPLES R CHINA SICHUAN UNION UNIV DEPT CHEM PROC MACHINERY CHENGDU 610065 PEOPLES R CHINA

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关键词： ydrocyclone central cone annular teeth separation sharpness classification efficiency separation characteristics