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A review on the hydraulic performance and erosion wear characteristic of the centrifugal slurry pump

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PARTICUOLOGY 2024年第12期95卷 370-392页

作者： Duan, Aoqiang lin, zhe Chen, Desheng Li, Yi zhejiang Sci Tech Univ Zhejiang Key Lab Multiflow & Fluid Machinery Hangzhou 310018 Peoples R China

The centrifugal slurry pump is widely applied for the transportation of liquid medium containing solid particles. The introduction of solid particles will lead to a decrease in efficiency and wear of the slurry pump. To solve this problem, it is imperative to review the hydraulic performance and erosion characteristic of slurry pumps under solid-liquid two-phase flow in recent years. In this review, firstly, the general structure and engineering application are introduced. Next, the experimental and simulation research methods of particle movement and erosion wear are explored. Then, the influence of solid particles on the hydraulic performance and particle distribution is analyzed. Afterwards, the variation laws of erosion wear under different flow-passing components and particle properties are clarified. Finally, according to the current research status and conclusions, the design optimization measures and future investigate direction are proposed, aiming to promote the resolution of wear damage and extend the service life of the slurry pump. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Centrifugal slurry pump Solid-liquid two-phase flow Hydraulic performance Particle distribution Erosion wear damage

Experimental Study of Cavitation Phenomenon in a Centrifugal Blood Pump Induced by the Failure of Inlet Cannula

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Chinese Journal of Mechanical Engineering 2014年第1期27卷 165-170页

作者： lin zhe RUAN Xiaodong ZOU Jun FU Xin The State Key Lab of Fluid Power Transmission and Control Zhejiang University

Cavitation of centrifugal blood pump is a serious problem accompany with the blocking failure of short inlet cannula. However, hardly any work has been seen in published literature on this complex cavitation phenomenon caused by the coupling effect of inlet cannula blocking and pumps suction. Even for cavitation studies on ordinary centrifugal pumps, similar researches on this issue are rare. In this paper, the roles of throttling, rotation speed and fluid viscosity on bubble inception and intensity in a centrifugal blood pump are studied, on the basis of experimental observations. An adjustable throttle valve installed just upstream blood pump inlet is used to simulate the throttling effect of the narrowed inlet cannula. The rotation speed is adjusted from 2 600 r/rain to 3 200 r/min. Glycerin water solutions are used to investigate the influences of kinetic viscosity. Bubbles are recorded with a high-speed video camera. Direct observation shows that different from cavitation in industrial centrifugal pumps, gas nuclei appears at the nearby of vane leading edges while throttling is light, then moves upstream to the joint position of inlet pipe and pump with the closing of the valve. It＇s found that the critical inlet pressure, obtained when bubbles are first observed, decreases linearly with viscosity and the slope is independent with rotation speeds; the critical inlet pressure and the inlet extreme pressure which is obtained when the throttle valve is nearly closed, fall linearly with rotation speed respectively and the relative pressure between them is independent with rotation speed and fluid viscosity. This paper studies experimentally on cavitation in centrifugal blood pump that caused by the failure of assembled short inlet cannula, which mav beneficial the desima of centrifugal blood Dumo with inlet cannula.

关键词： centrifugal blood pump cavitation viscosity cannula diameter rotation speed

Boundedness and Spectrum of Multiplicative Convolution Operators Induced by Arithmetic Functions

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Acta Mathematica Sinica,English Series 2019年第8期35卷 1300-1310页

作者： Kibrom G.EBREMESKEL lin zhe HUANG Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190P.R.China Department of Mathematics College of Natural and Computational SciencesAksum UniversityAksumTigrayEthiopia

In this paper, we consider a multiplicative convolution operator Mf acting on a Hilbert spaces l^2(N,ω;). In particular, we focus on the operators M1 and Mμ, where μ, is the Mobius function. We investigate conditions on the weight ω under which the operators M1 and Mμ are bounded. We show that for a positive and completely multiplicative function f,M1 is bounded on l^2(N, f^2) if and only if ||f||1 1. As an application, we obtain some results on the spectrum of M1^*M1 and M^*μMμ. Moreover, von Neumann algebra generated by a certain family of bounded operators is also considered.

关键词： Arithmetic functions Mobius function von Neumann algebra

Effect of Inlet Guide Vanes on the Performance of Small Axial Flow Fan

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Journal of Thermal Science 2017年第6期26卷 504-513页

作者： LIU Yang lin zhe lin Peifeng JIN Yingzi Toshiaki Setoguchi Heuy Dong Kim Key Laboratory of Fluid Transmission Technology of zhejiang Province Zhejiang Sci-Tech University Department of Mechanical Engineering Saga University School of Mechanical Engineering Andong National University

Effects of the inlet guide vanes on the static characteristics, aerodynamic noise and internal flow characteristics of a small axial flow fan are studied in this work. The inlet guide vanes with different outlet angle are designed, which are mounted on the casing and located at the upstream of the impeller of the prototype fan. Both steady and unsteady flow simulations arc performed. The steady flow is simulated by the calculations of Navier-Stokes equa- tions coupled with RNG k-epsilon turbulence model, while the unsteady flow is computed with large eddy simu- lation. According to the theoretical analysis, the inlet guide vanes with outlet angle of 60° are regarded as the op- timal inlet guide vanes. The static characteristic experiment is carried out in a standard test rig and the aerody- namic noise is tested in a semi-anechoic room. Then, performances of the fan with optimal inlet guide vanes are compared with those of the prototype fan. The results show that there is reasonable agreement between the simu- lation results and the experimental data. It is found that the static characteristics of small axial flow fan is im- proved obviously after installing the optimal inlet guide vanes. Meanwhile, the optimal inlet guide vanes have effect on reducing noise at the near field, but have little effect on the noise at the far field.

关键词： small axial flow fan inlet guide vanes static characteristics aerodynamic noise internal flow characteristics

Optimised trajectory tracking control for quadrotors based on an improved beetle antennae search algorithm

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Journal of Control and Decision 2023年第3期10卷 382-392页

作者： zhe lin Ping Li Zhaoqi Zhang College of Information Science and Engineering Huaqiao UniversityXiamenPeople’s Republic of China

This paper focuses on the trajectory tracking of quadrotors under bounded external *** optimised robust controller is proposed to drive the position and attitude ofa quadrotor converge to their references quickly. At first, nonsingular fast terminal slidingmode control is developed, which can guarantee not only the stability but also finite-timeconvergence of the closed-loop system. As the parameters of the designed controllers playa vital role for control performance, an improved beetle antennae search algorithm is proposedto optimise them. By employing the historical information of the beetle’s antennaeand dynamically updating the step size as well as the range of its searching, the optimisingis accelerated considerably to ensure the efficiency of the quadrotor control. The superiorityof the proposed control scheme is demonstrated by simulation experiments, from whichone can see that both the error and the overshooting of the trajectory tracking are reducedeffectively.

关键词： Quadrotor control trajectory tracking nonsingular fast terminal sliding mode control optimisation improved beetle antennae search algorithm

Effect of the Uneven Circumferential Blade Space on the Performance of Small Axial Flow Fan

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Journal of Thermal Science 2016年第6期25卷 492-500页

作者： LIU Yang lin zhe lin Peifeng JIN Yingzi Toshiaki Setoguchi Heuy Dong Kim Key Laboratory of Fluid Transmission Technology of Zhcjiang Province Zhejiang Sci-Tech UniversityHangzhou310018China Department of Mechanical Engineering Saga UniversityHonjo-machiSaga840-8502Japan School of Mechanical Engineering Andong National UniversitySeongcheon-Dong1375Gyeongdong-RDAndongGyeongsangnuk-DO760-749Korea

Effects of the uneven circumferential blade space on static characteristics and aerodynamic noise of a small axial flow fan are studied in this *** blade angle modulation is adopted to design a series of unequally spaced fans,which have different maximum of modulation angular *** steady flow is simulated by the calculations of Navier-Stokes equations coupled with RNG k-epsilon turbulence model,while the unsteady flow is computed with large eddy *** to theoretical analysis,a fan with a maximum of modulation angular displacement of 6° is regarded as the optimal unequally spaced *** experiment of static characteristic is carried out in a standard wind tunnel and the aerodynamic noise of both fans is tested in a semi-anechoic ***,performances of the optimal unequally spaced fan are compared with those of the prototype *** results show that there is reasonable agreement between the simulation results and the experimental *** is found that the discrete noise of the optimal unequally spaced fan is lower than that of the prototype fan at the near field monitoring *** can be explained that the total pressure fluctuation of the optimal unequally spaced fan is much more regular than that of the prototype fan.

关键词： prototype blade fluctuation uneven turbulence aerodynamic rotating unsteady Mellin slowly

Effect of Placements (horizontal with vertical) on Gas-solid Flow and Particle Impact Erosion in Gate Valve

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Journal of Thermal Science 2014年第6期23卷 558-563页

作者： lin zhe ZHU linhang CUI Baoling LI Yi RUAN Xiaodong The zhejiang Provincial Key Laboratory of Fluid Transmission Technology Zhejiang Sci-Tech University 1201 Chu Kochen Honor College Zhejiang University State Key Laboratory of Fluid Power Transmission and Control Zhejiang University

Gate valve has various placements in the practical *** to the effect of gravity,particle trajectories and erosions are distinct between *** in this study,gas-solid flow properties and erosion in gate valve for horizontal placement and vertical placement are discussed and compared by using Euler-Lagrange simulation *** structure of a gate valve and a simplified structure are *** simulation procedure is validated in our published paper by comparing with the experiment data of a pipe and an *** results show that for all investigated open degrees and Stokes numbers(St),there are little difference of gas flow properties and flow coefficients between two *** is also found that the trajectories of particles for two placements are mostly identical when St << 1,making the erosion independent of *** the increase of St,the distinction of trajectories between placements becomes more obvious,leading to an increasing difference of the erosion ***,the total erosion ratio of surface T for horizontal placement is two orders of magnitudes larger than that for vertical placement when the particle diameter is 250 μm.

关键词： gate valve placement flow properties erosion

Origin of itinerant ferromagnetism in two-dimensional Fe_(3)GeTe_(2)

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Chinese Physics B 2021年第4期30卷 119-124页

作者： Xi Chen zheng-zhe lin Li-Rong Cheng School of Physics and Optoelectronic Engineering Xidian UniversityXi'an 710071China

Magnetic order in two-dimensional systems was not supposed to exist at finite *** recent years,the successful preparation of two-dimensional ferromagnetic materials such as CrI_(3),Cr_(2) Ge_(2) Te_(6),and Fe_(3)GeTe_(2) opens up a new chapter in the remarkable field of two-dimensional ***,we report on a theoretical analysis of the stability of ferromagnetism in Fe_(3)GeTe_(2).We uncover the mechanism of holding long-range magnetic order and propose a model to estimate the Curie temperature of Fe_(3)GeTe_(2).Our results reveal the essential role of magnetic anisotropy in maintaining the magnetic order of two-dimensional *** theoretical method used here can be generalized to future research of other magnetic two-dimensional systems.

关键词： two-dimensional(2D)ferromagnetism spin wave magnetic anisotropy

Identification and temporal expression profiles of cuticular proteins in the endoparasitoid wasp,Microplitis mediator

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Insect Science 2020年第5期27卷 998-1018页

作者： Olga Volovych zhe lin Jie Du Hong Jiang zhen Zou State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina

Recently,parasitoid wasp species Microplitis mediator has evoked increasing research attention due to its possible use in the control of Lepidoptera *** insect development involves changes in cuticle composition,identification and expression analysis of *** cuticular proteins may clarify the mechanisms involved in parasite development *** found 70 cuticular proteins from the *** transcrip-tome and divided them into seven distinct *** profiling indicated that most of these cuticular protein genes have expression peaks specific for one particular developmental stage of *** and pupae have the highest number of tran-scriptionally active cuticular protein genes(47 and 52 respectively).Only 12 of these genes maintained high expression activity during late larval *** analysis of two larval proteins,MmCPR3 and MmCPR 14,suggested their important role in the proper organization of the cuticle layers of *** *** larval development,normal cuticle formation can be supported by a limited number of cuticular proteins.

关键词： cuticular protein expression pattern Microplis mediator transcriptome