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Numerical investigation of sinusoidal pulsating gas intake to intensify the gas-slag momentum transfer in the top-blown smelting furnace

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 301-314页

作者： Zhanghao Wan Shiliang Yang Desong Kong Dongbo Li Jianhang Hu Hua Wang State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming 650093China Southwest Copper Branch Yunnan Copper Co.Ltd.Kunming 650102China

The variation characteristics of bubble morphology and the thermal-physical properties of bubble boundary in the top-blown smelting furnace were explored by means of the computational fluid dynamics method.The essential aspects of the fluid phase(e.g.,splashing volume,dead zone of copper slag,and gas penetration depth)were explored together with the effect of sinusoidal pulsating gas intake on the momentum-transfer performance between phases.The results illustrated that two relatively larger vortices and two smaller vortices appear in the bubble waist and below the lance,respectively.The expansion of larger ones as well as the shrinking of smaller ones combine to cause the contraction of the bubble waist.Compared to the results of the case with a fixed gas injection velocity(V_(g)=58 m/s),the splashing volume and dead zone volume of the slag under the V_(g)=58+10sin(2πt)condition are reduced by 24.9%and 23.5%,respectively,where t represents the instant time.Gas penetration depth and slag motion velocity of the latter are 1.03 and 1.31 times high-er than those of the former,respectively.

关键词： top-blown smelting furnace pulsed flow volume of fluid penetration depth splashing volume

Numerical simulation research on multiphase flow of aviation centrifugal pump based on OpenFOAM

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Chinese Journal of Aeronautics 2024年第4期37卷 256-275页

作者： Xianwei LIU Jiangfeng FU Junjie YANG Dewen YIN Zhenhua ZHOU Huacong LI College of Power and Energy Northwestern Polytechnical UniversityXi’an 710072China Norinco Group Testing and Research Institute Huayin 714200China AECC Xi’an Engine Control Technology Co.Ltd. Xi’an 710077China AECC Guizhou Honglin Aero Engine Control Technology Co.Ltd. Guiyang 550009China

This paper aims to tackle the calculation efficiency problem raised in the cavitation-flow simulation of the aviation centrifugal pump due to the fading-away interface resulting from the dissipation of numerics used in the phase-change control equation for unstructured-grid multiphase flow,and due to the limitation of flow time-step in whole flow regimes,the control equation of vapor–liquid two-phase flow considering cavitation mass transport is established firstly,modifying the momentum equation by introducing the surface tension,and adding the artificial convective flow to the phase equation to solve the numerical dissipation problem.Secondly,in consideration of the local time step principle and based on the multi-dimensional general limiter algorithm with explicit solutions under the OpenFOAM platform,a solution method of steady-state VOF (volume of fluid) model considering cavitation two-phase change is constructed,and the feasibility of this method is verified by NACA hydrofoil and NASA flat plate inducer.Finally,based on the platform developed,the cavitation performance of an aviation centrifugal pump inducer is analyzed.The research results show that the error of the calculated cavitation pressure distribution for NACA hydrofoil between the simulation test and the experimental-test is less than 5%,and the maximum error of calculated cavitation number at pump head dropping for NASA high-speed flat plate inducer between the simulation test and the experimental-test is 2.1%.The cavitation area observed in the simulation test is the same as that obtained in the high-speed photography test.Based on the OpenFOAM simulation method,the position of pump head dropping of the fuel centrifugal pump can be accurately captured.The error of the calculated cavitation number at pump head dropping between the simulation test and the experimental test is about 3.7%,showing high calculation accuracy.

关键词： Aero engine Fuel centrifugal pump Multiphase flow OpenFOAM volume of fluid

基于STAR-CCM+的船体周围流体流动数值分析及验证结果

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哈尔滨工程大学学报（英文版） 2024年第2期23卷 276-291页

作者： Doyal Kumar Sarker MdShahjada Tarafder Bangladesh University of Engineering and Technology-Naval Architecture and Marine Engineering BUETDhaka-1000 Dhaka 1000Bangladesh

In this paper,numerical analyses of fluid flow around the ship hulls such as Series 60,the Kriso Container Ship(KCS),and catamaran advancing in calm water,are presented.A commercial computational fluid dynamic(CFD)code,STAR-CCM+is used to analyze total resistance,sinkage,trim,wave profile,and wave pattern for a range of Froude numbers.The governing RANS equations of fluid flow are discretized using the finite volume method(FVM),and the pressure-velocity coupling equations are solved using the SIMPLE(semi-implicit method for pressure linked equations)algorithm.volume of fluid(VOF)method is employed to capture the interface between air and water phases.A fine discretization is performed in between these two phases to get a higher mesh resolution.The fluid-structure interaction(FSI)is modeled with the dynamic fluid-body interaction(DFBI)module within the STAR-CCM+.The numerical results are verified using the results available in the literatures.Grid convergence studies are also carried out to determine the dependence of results on the grid quality.In comparison to previous findings,the current CFD analysis shows the satisfactory results.

关键词： Computational fluid dynamics Grid convergence Resistance STAR-CCM+ volume of fluid

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驱替压力梯度对水驱油田采收率影响研究

计算物理 2024年第3期41卷 325-333页

作者：崔文富中国石化胜利油田分公司胜利采油厂山东东营257000

针对特高含水期砂岩油藏,利用volume of fluid(VOF)可以追踪相界面动态变化、再现微观渗流物理过程的优势,研究了驱替压力梯度对剩余油微观赋存状态和水驱采收率的影响。通过分析微观孔隙结构内的渗流特征和剩余油赋存状态,揭示了驱替... 详细信息

针对特高含水期砂岩油藏,利用volume of fluid(VOF)可以追踪相界面动态变化、再现微观渗流物理过程的优势,研究了驱替压力梯度对剩余油微观赋存状态和水驱采收率的影响。通过分析微观孔隙结构内的渗流特征和剩余油赋存状态,揭示了驱替压力梯度对水驱采收率的影响规律:驱替压力梯度增大能突破小喉道毛管力,形成新的渗流通道,进而增大水驱采出程度;原油黏度和润湿性会对不同压力梯度下采出程度产生影响。

关键词：高含水水驱采收率剩余油 volume of fluid 驱替压力梯度

Modelling and analysis of initial icing roughness with fixed-grid enthalpy method based on DPM-VOF algorithm

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Chinese Journal of Aeronautics 2022年第7期35卷 168-178页

作者： Jie LIU Peng KE Department of Civil Helicopter Research and Development China Helicopter Research and Development InstituteTianjin 300000China School of Transportation Science and Engineering Beihang UniversityBeijing 100191China

Ice particles could form under the continuous impingement of incoming supercooled droplets in icing conditions,which will change the surface roughness to enhance the further heat and mass transfer during icing process.A fixed-grid porous enthalpy method based on the improved Discrete Phase Model(DPM)and volume of fluid(VOF)integrated algorithm is developed to solve the multiphase heat transfer problem to give more detailed demonstration of the formation of initial ice roughness.The algorithms to determine the criterion of transformation from DPM to VOF and the allocation of source items during transformation are improved to the general DPM-VOF algorithm.Two verification cases,namely two glycerine-solution droplets impact and single droplet freeze,are conducted to verify the accuracy and reliability of the enthalpy-DPMVOF method,where the simulation results match well with experiment phenomena.Ice roughness on a NACA0012 airfoil is precisely captured and the effects on convective heat transfer characteristics are preliminarily revealed.The results illustrate that the enthalpy-DPM-VOF method could successfully capture the characteristics of motion and the phase change process of droplet,as well as balance the calculation accuracy and efficiency.

关键词： Discrete phase model Fixed-grid porous enthalpy method Ice roughness Icing modelling Integrated algorithm Multiphase heat transfer volume of fluid

Cavitation Evolution Around a Twist Hydrofoil by Large Eddy Simulation(LES)with Mesh Adaption

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Journal of Ocean University of China 2023年第3期22卷 627-636页

作者： WANG Zhengdong LI Linmin LI Xiaojun YANG Chunye ZHU Zuchao Key Laboratory of fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou 310018China Ebara Great Pumps Co. Ltd.Wenzhou 325200China

The cavitating flow around a Delft Twist-11 hydrofoil is simulated using the large eddy simulation approach.The volume-of-fluid method incorporated with the Schnerr-Sauer cavitation model is utilized to track the water-vapor interface.Adaptive mesh refinement(AMR)is also applied to improve the simulation accuracy automatically.Two refinement levels are conducted to verify the dominance of AMR in predicting cavitating flows.Results show that cavitation features,including the U-type structure of shedding clouds,are consistent with experimental observations.Even a coarse mesh can precisely capture the phase field without increasing the total cell number significantly using mesh adaption.The predicted shedding frequency agrees fairly well with the experimental data under refinement level 2.This study illustrates that AMR is a promising approach to achieve accurate simulations for multiscale cavitating flows within limited computational costs.Finally,the force element method is currently adopted to investigate the lift and drag fluctuations during the evolution of cavitation structure.The mechanisms of lift and drag fluctuations due to cavitation and the interaction between vorticity forces and cavitation are explicitly revealed.

关键词： cavitating flow adaptive mesh refinement volume of fluid vorticity force force element method

Scouring of a granular bed by dam break: Experimental study and numerical simulation by a VOF-LPT coupling

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International Journal of Sediment Research 2023年第3期38卷 432-445页

作者： Quyen Thi Le Nguyen Viet Dung Nguyen Patrice Coorevits EPROAD Research Unit University of Picardie Jules Verne IUT of Aisne Hanoi University of Civil Engineering

The first part of the research reported here consists of an experimental campaign to study the scouring of a granular bed(glass beads, sand) induced by a dam break in an open channel. Two configurations are considered: with and without cylinders. In the second part of this study, the volume of fluid method coupled with the shear stress transport turbulent model and the lagrangian particle tracking method is used to simulate the local scour processes. The four-way coupling is realized by considering the drag force and collisions between particles. Using a vortex map and velocity profiles, the flow dynamics and scour pattern can be studied. The current research also focuses on the profiles of the erodible particle bed and the sediment transport rate to study the effects of a cylinder on local scour. The presence of the cylinder increases the experimental erosion depth by up to 42%. It was found that for relatively close particle diameters(2 and 3 mm), a granular bed with larger porosity(larger diameter) erodes the most.Experimentally and numerically it was found that the center of the granular bed experiences more erosion compared to the channel sides. In the last part of the research, comparisons between the numerical results and the experimental data allowed risk areas to be identified and the roles of porosity,sediment density, and flow dynamics on erosion to be identified.

关键词： volume of fluid Lagrangian particle tracking Scour Granular bed Cylinder Dam break

Numerical Simulation of Low Reynolds Number fluid-Structure Interaction with Immersed Boundary Method

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Chinese Journal of Aeronautics 2009年第5期22卷 480-485页

作者： Ming Pingjian Zhang Wenping School of Power and Energy Engineering Harbin Engineering University Harbin 150001 China

This article introduces a numerical scheme on the basis of semi-implicit method for pressure-linked equations （SIMPLE） algorithm to simulate incompressible unsteady flows with fluid-structure interaction. The Navier-Stokes equation is discretized spatially with collocated finite volume method and Eulerian implicit method in time domain. The hybrid method that combines immersed boundary method （IBM） and volume of fluid （VOF） method is used to deal with rigid body motion in fluid domain. The details of movement of immersed boundary （IB） and calculation of VOF are also described. This method can be easily applied to any existing finite-volume-based computational fluid dynamics （CFD） solver without complex operation, with which fluid flow interaction of arbitrarily complex geometry can be realized on a fixed mesh. The method is verified by low Reynolds number flows passing both stationary and oscillating cylinders. The drag and lift coefficients acquired by the study well accord with other published results, which indicate the reasonability of the proposed method.

关键词： fluid-structure interaction immersed boundary method volume of fluid vortex shedding incompressible flow

Large eddy simulation of free-surface flows

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Journal of Hydrodynamics 2017年第1期29卷 1-12页

作者： Richard J.McSherry Ken V.Chua Thorsten Stoesser School of Engineering Cardiff UniversityCardiffCF24 3AAUK

This paper introduces and discusses numerical methods for flee-surface flow simulations and applies a large eddy simula- tion （LES） based flee-surface-resolved CFD method to a couple of flows of hydraulic engineering interest. The advantages, dis- advantages and limitations of the various methods are discussed. The review prioritises interface capturing methods over interface tracking methods, as these have shown themselves to be more generally applicable to viscous flows of practical engineering interest, particularly when complex and rapidly changing surface topologies are encountered. Then, a LES solver that employs the level set method to capture flee-surface deformation in 3-D flows is presented, as are results from two example calculations that concern com- plex low submergence turbulent flows over idealised roughness elements and bluff bodies. The results show that the method is capable of predicting very complex flows that are characterised by strong interactions between the bulk flow and the free-surface, and permits the identification of turbulent events and structures that would be very difficult to measure experimentally.

关键词： Large eddy simulation free-surface level set method volume of fluid