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Numerical Investigation of Penetration in Ceramic/Aluminum Targets Using Smoothed Particle hydrodynamics Method and Presenting a Modified Analytical Model

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Computer Modeling in Engineering & Sciences 2017年第3期113卷 295-323页

作者： Ehsan Hedayati Mohammad Vahedi Department of Mechanical Engineering College of Technical EngineeringSaveh BranchIslamic Azad UniversitySavehIran Department of Mechanical Engineering College of Technical EngineeringSaveh BranchIslamic Azad UniversitySavehIran.

Radius of ceramic cone can largely contribute into final solution of analytic models of penetration into ceramic/metal targets.In the present research,a modified model based on radius of ceramic cone was presented for ceramic/aluminum targets.In order to investigate and evaluate accuracy of the presented analytic model,obtained results were compared against the results of the Florence’s analytic model and also against numerical modeling results.The phenomenon of impact onto ceramic/aluminum composites were modeled using smoothed particle hydrodynamics(SPH)implemented utilizing ABAQUS Software.Results indicated that,with increasing initial velocity and ceramic thickness and decreasing support layer thickness,the radius of ceramic cone decreases;this ends up increasing residual velocity of the projectile and penetration time and extending the area across which the pressure is distributed.These findings indicate enhanced levels of target energy absorption and the required energy for bending and tensioning the target.As such,it can be observed that,at the same thickness and areal density,the ceramic target has its efficiency enhanced with increasing ceramic thickness and decreasing the support layer thickness.Finally,the results revealed that the associated data with SPH confirm the modified analytic model at higher accuracy than the Florence’s analytic model.

关键词： Smoothed particle hydrodynamics Florence’s analytic model modified analytical model energy absorption ABAQUS penetration

Unconventional hydrodynamics of hybrid fluid made of liquid metals and aqueous solution under applied fields

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Frontiers in Energy 2018年第2期12卷 276-296页

作者： Xu-Dong ZHANG Yue SUN Sen CHEN Jing LIU Beijing Key Lab of Cryo-Biomedical Engineering and Key Lab of Cryogenics Technical Institute of Physics and Chemistry ChineseAcademy of Sciences Beijing 100190 School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China Department of Biomedical Engineering School of Medicine Tsinghua University Beijing 100084 China

The hydrodynamic characteristics of hybrid fluid made of liquid metal/aqueous solution are elementary in the design and operation of conductive flow in a variety of newly emerging areas such as chip cooling, soft robot, and biomedical practices. chemical properties, such as In terms of physical and density, thermal conductivity and electrical conductivity, their huge differences between the two fluidic phases remain a big challenge for analyzing the hybrid flow behaviors. Besides, the liquid metal immersed in the solution can move and deform when administrated with non-contact electromagnetic force, or even induced by redox reaction, which is entirely different from the cases of conventional contact force. Owing to its remarkable capability in flow and deformation, liquid metal immersed in the solution is apt to deform on an extremely large scale, resulting in marked changes on its boundary and interface. However, the working mechanisms of the movement and deformation of liquid metal lack appropriate models to describe such scientific issues via a set of well-established unified equations. To promote investigations in this important area, the present paper is dedicated to summarizing this unconventional hydrodynamics from experiment, theory, and simulation. Typical experimental phenomena and basic working mechanisms are illustrated, followed by the movement and deformation theories to explain these phenomena. Several representative simulation methods are then proposed to tackle the governing functions of the electrohydrodynamics. Finally, prospects and challenges are raised, offering an insight into the new physics of the hybrid fluid under applied fields.

关键词： liquid metal hybrid fluid hydrodynamics surface tension applied fields self-actuation

Numerical Simulation of Bubble Formation at a Single Orifice in Gas-fluidized Beds with Smoothed Particle hydrodynamics and Finite Volume Coupled Method

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Computer Modeling in Engineering & Sciences 2015年第1期104卷 41-68页

作者： F.Z.Chen H.F.Qiang W.R.Gao 601 Staff Room Xi’an Hi–Tech InstituteXi’anShanxiPRCPC 710025

A coupled method describing gas–solid two-phase flow has been proposed to numerically study the bubble formation at a single orifice in gas-fluidized beds.Solid particles are traced with smoothed particle hydrodynamics,whereas gas phase is discretized by finite volume method.Drag force,gas pressure gradient,and volume fraction are used to couple the two methods.The effect of injection velocities,particle sizes,and particle densities on bubble growth is analyzed using the coupled method.The simulation results,obtained for two-dimensional geometries,include the shape and diameter size of a bubble as a function of time;such results are compared with experimental data,previous numerical results,and other approximate model predictions reported in the literature.Moreover,the flow profiles of gas and particle phases and the temperature distribution by the heat transfer model around the forming bubble are also discussed.All results show that the coupled method efficiently describes of the bubble formation in fluidized beds.The proposed method is applicable for solving gas–solid two-phase flow in fluidization.

关键词： coupled method smoothed particle hydrodynamics finite volumemethod bubble formation heat transfer fluidization

EXPERIMENTS OF hydrodynamics AND STABILITY OF IMMERSED TUBE TUNNEL ON TRANSPORTATION AND IMMERSING

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Journal of hydrodynamics 2001年第2期13卷 121-126页

作者： Zhan, D.X. Wang, X.Q. Dept. of Naval Arch. and Ocean Eng. Wuhan Univ. of Technol. Wuhan 430063 China

Effects of environment conditions, such as current, wave etc., are more important for immersed tube tunnel's transportation and immersing. The hydrodynamics and stability of immersed tube tunnel during its towing and immersing are interested for departments of design and construction. A serial model tests are made in towing tank and water channel for Nanjing immersed tube tunnel, and the first immersed tunnel has been designed in Yangtzi River in China. The hydrodynamic forces and rope tensions of the tunnel are measured with strain balances when it is towed by ship and immersed by winches for a different current velocity and wave height. In addition, the stability of tunnel for a different ballast water is tested and discussed.

关键词： hydrodynamics Stability Tensile testing Test facilities

Application research of narrow band Internet of things buoy and surface hydrodynamics monitoring

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Acta Oceanologica Sinica 2021年第8期40卷 176-181页

作者： Yiqun Xu Jia Wang Li Guan School of Marine Engineering Jimei UniversityXiamen 361021China Fujian Key Laboratory of Ship and Ocean Engineering Xiamen 361021China

This paper applies the narrow band Internet of things communication technology to develop a wireless network equipment and communication system, which can quickly set up a network with a radius of 100 km on water surface. A disposable micro buoy based on narrow-band Internet of things and Beidou positioning function is also developed and used to collect surface hydrodynamic data online. In addition, a web-based public service platform is designed for the analysis and visualization of the data collected by buoys. Combined with the satellite remote sensing data, the study carries a series of marine experiments and studies such as sediment deposition tracking and garbage floating tracking.

关键词： narrow band Internet of things abandoned buoy hydrodynamics ocean monitoring satellite remote sensing image

Staggered Lagrangian Discretization Based on Cell-Centered Riemann Solver and Associated hydrodynamics Scheme

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Communications in Computational Physics 2011年第9期10卷 940-978页

作者： Pierre-Henri Maire Raphael Loubere Pavel Vachal CEA-CESTA BP 233114Le BarpFrance Institut de Mathematiques de Toulouse(IMT)Universite Paul-Sabatier and CNRS ToulouseFrance FNSPE Czech Technical University(CTU)in PragueCzech Republic

The aim of the present work is to develop a general formalism to derive staggered discretizations for Lagrangian hydrodynamics on two-dimensional unstructured grids.To this end,we make use of the compatible discretization that has been initially introduced by E.J.Caramana et al.,in J.Comput.Phys.,146(1998).Namely,momentum equation is discretized by means of subcell forces and specific internal energy equation is obtained using total energy conservation.The main contribution of this work lies in the fact that the subcell force is derived invoking Galilean invariance and thermodynamic consistency.That is,we deduce a general form of the sub-cell force so that a cell entropy inequality is satisfied.The subcell force writes as a pressure contribution plus a tensorial viscous contribution which is proportional to the difference between the nodal velocity and the cell-centered velocity.This cell-centered velocity is a supplementary degree of freedom that is solved by means of a cell-centered approximate Riemann solver.To satisfy the second law of thermodynamics,the local subcell tensor involved in the viscous part of the subcell force must be symmetric positive definite.This subcell tensor is the cornerstone of the scheme.One particular expression of this tensor is given.A high-order extension of this discretization is provided.Numerical tests are presented in order to assess the efficiency of this approach.The results obtained for various representative configurations of one and two-dimensional compressible fluid flows show the robustness and the accuracy of this scheme.

关键词： Lagrangian scheme Riemann solver artificial viscosity hydrodynamics compressible flow

hydrodynamics AND AXIAL MIXING OF LIQUIDSOLID SYSTEM IN OPEN TURBINE ROTATING DISC CONTACTOR

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Chinese Journal of Chemical Engineering 1992年第1期 28-38页

作者：陈晓祥汪鸿涛李宽宏苏元复 Chemical Engineering Research Centre East China Institute of Chemical Technology Shanghai 200237

The open turbine rotating disc contactor (OTRDC) has been installed simply by adding three narrow strips to the lower surface of each rotating disc in the rotating disc contactor (RDC), so it can be used for the system with high solid particle content. hydrodynamics and axial mixing have been investigated in a 0.152m diameter OTRDC of different compartment height for the system of tap water and quartz particles. A model has been developed to describe the flow of liquid and solid phases. The solid phase holdup can be calculated satisfactorily according to the model equations. Axial mixing data have been treated by the backflow model and the correlations for predicting backflow ratios of liquid and solid phases in OTRDC have been presented.

关键词： hydrodynamics axial mixing liquid-solid system column contactor

Side Wall Effects on the hydrodynamics of a Floating Body by ImageGreen Function Based on TEBEM

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Journal of Marine Science and Application 2018年第3期17卷 353-361页

作者： Jikang Chen Lijia Wang Wenyang Duan College of Shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China Joint Laboratory for Smart Ocean Technology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237 China

A novel numerical model based on the image Green function and first-order Taylor expansion boundary element method(TEBEM), which can improve the accuracy of the hydrodynamic simulation for the non-smooth body, was developed to calculate the side wall effects on first-order motion responses and second-order drift loads upon offshore structures in the wave tank. This model was confirmed by comparing it to the results from experiments on hydrodynamic coefficients, namely the first-order motion response and second-order drift load upon a hemisphere, prolate spheroid, and box-shaped barge in the wave tank. Then,the hydrodynamics of the KVLCC2 model were also calculated in two wave tanks with different widths. It was concluded that this model can predict the hydrodynamics for offshore structures effectively, and the side wall has a significant impact on the firstorder quantities and second-order drift loads, which satisfied the resonant rule.

关键词： Taylorexpansionboundaryelementmethod Sidewalleffects Image Green function hydrodynamics Sharp comer floating body

Application of CFD Modeling to hydrodynamics of CycloBio Fluidized Sand Bed in Recirculating Aquaculture Systems

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Journal of Ocean University of China 2014年第1期13卷 115-124页

作者： LIU Yao SONG Xiefa LIANG Zhenlin PENG Lei College of Fisheries Ocean University of China College of Marine Science Shandong University

To improve the efficiency of a CycloBio fluidized sand bed(CB FSB) in removal of dissolved wastes in recirculating aquaculture systems, the hydrodynamics of solid-liquid flow was investigated using computational fluid dynamics(CFD) modeling tools. The dynamic characteristics of silica sand within the CB FSB were determined using three-dimensional, unsteady-state simulations with the granular Eulerian multiphase approach and the RNG k-ε turbulence model, and the simulation results were validated using available lab-scale measurements. The bed expansion of CB FSB increased with the increase in water inflow rate in numerical simulations. Upon validation, the simulation involving 0.55 mm particles, the Gidaspow correlation for drag coefficient model and the Syamlal-O'Brien correlation for kinetic granular viscosity showed the closest match to the experimental results. The volume fraction of numerical simulations peaked as the wall was approached. The hydrodynamics of a pilot-scale CB FSB was simulated in order to predict the range of water flow to avoid the silica sand overflowing. The numerical simulations were in agreement with the experimental results qualitatively and quantitatively, and thus can be used to study the hydrodynamics of solid-liquid multiphase flow in CB FSB, which is of importance to the design, optimization, and amplification of CB FSBs.

关键词： aquaculture water recirculating fluidized sand bed hydrodynamics numerical simulation multiphase flow