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Novel oxygen-enrichment method using annular air curtain for single-head roadway of plateau mine

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Building Simulation 2023年第7期16卷 1097-1113页

作者： Zijun Li Rongrong Li Yu Xu Qiaoli Wang School of Resources&Safety Engineering Central South UniversityChangsha 410083China

The low-oxygen environment restricts the exploitation of mineral resources on plateaus and affects miner’s *** paper proposes an oxygen-enrichment method using an annular air *** numerical simulation and experiments,it was confirmed that the proposed method improves the breathing environment in the single-head roadway of a plateau *** fluid dynamics(cfd)was used to investigate the oxygen-enriching effect and oxygen spatial distribution regularities after using the proposed oxygen-enrichment method in the single-head roadway of a plateau *** reliability of the cfd model was confirmed by *** testing was conducted to investigate the influence degree and optimal level combination of factors influencing oxygen *** results demonstrate that the annular air curtain effectively prevented oxygen loss,thus forming a local oxygen-rich space and improving the effective utilization rate of *** supply concentration and velocity are positively correlated with the oronasal oxygen mass fraction through a linear function,while the air curtain outlet wind velocity is negatively correlated with the oronasal oxygen mass fraction through a linear *** annular air curtain diameter and oronasal oxygen mass fraction do not have an obvious functional *** the annular air curtain diameter was greater than 0.9 m,the oronasal oxygen mass fraction was stable at approximately 25.30%.The influencing factors of the novel oxygen-enrichment method are,in descending order,as follows:oxygen supply concentration,annular air curtain diameter,air curtain outlet wind velocity,and oxygen supply *** optimal level combination is oxygen supply concentration of 100%,oxygen supply velocity of 11 m/s,air curtain outlet wind velocity of 1.5 m/s,and annular air curtain diameter of 0.9 m.

关键词： plateau mine heading face oxygen enrichment air curtain cfd method

Diffusion characteristics of oxygenic–thermal coupled airflow in high-altitude sleeping environment

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Building Simulation 2024年第10期17卷 1749-1765页

作者： Cong Song Xiaohui Li Yanfeng Liu Longxiang Gao State Key Laboratory of Green Building Xi’an University of Architecture and TechnologyXi’anShaanxi 710055China School of Building Services Science and Engineering Xi’an University of Architecture and TechnologyXi’anShaanxi 710055China

About 1/3 of human life is spent *** hypoxic and cold environment in high-altitude areas leads to sleep disorders that are more prominently harmful to the human *** improve the quality of human sleep in high-altitude areas,this study explored the thermal and oxygen environment regulation for plateau *** this study,the influencing factors of the diffusion of oxygenic–thermal coupled airflow were determined through the theoretical analysis of a thermal fluid mechanic *** study used computational fluid dynamics(cfd)to investigate the diffusion characteristics of the oxygenic–thermal coupled airflow with a sleeping experiment conducted on the *** results showed that the influence of the thermal plume at 0.1 m near the human face was larger,and the oxygenic–thermal coupled airflow diffusion process was mainly divided into three phases over *** size and time to stabilize the oxygen volume fraction in the inhalation zone varied between conditions and were strongly influenced by the temperature difference of the supply *** effects of the thermal and oxygen environment were analyzed using indicators such as facial-area speed ratio,draft risk,and personal oxygen inhalation *** optimal design strategies were recommended with an outlet air velocity of 1.5 m/s,a temperature difference of 8 K between the outlet airflow and the indoor background air,and an outlet oxygen volume fraction of 30%.The results can provide implications for regulating the thermal and oxygen environment to improve human sleep quality in high-altitude areas.

关键词： high altitudes oxygenic–thermal coupled airflow sleep environment cfd method

Experimental and Numerical Investigations of Ship Parametric Rolling in Regular Head Waves

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China Ocean Engineering 2018年第4期32卷 431-442页

作者： MA Shan GE Wen-peng R.C.Ertekin HE Qiang DUAN Wen-yang College of Shipbuilding Engineering Harbin Engineering University

Parametric rolling is one of five types of the ship stability failure modes as proposed by IMO. The periodic change of the metacentric height is often considered as the internal cause of this phenomenon. Parametric rolling is a complex nonlinear hydrodynamic problem, often accompanied by large amplitude vertical motions of ships. In recent years,the Reynolds-averaged Navier–Stokes(RANS) equation simulations for viscous flows have made great progress in the field of ship seakeeping. In this paper, the parametric rolling for the C11 containership in regular waves is studied both experimentally and numerically. In the experiments, parametric rolling amplitudes at different drafts, forward speeds and wave steepnesses are analyzed. The differences in the steady amplitudes of parametric rolling are observed for two drafts. The effect of the incident wave steepness(or wave amplitude) is also studied, and this supports previous results obtained on limits of the stability for parametric rolling. In numerical simulations, the ship motions of parametric rolling are analyzed by use of the potential-flow and viscous-flow methods. In the viscousflow method, the Reynolds-averaged Navier–Stokes equations are solved using the overset grid method. The numerical accuracies of the two methods at different wave steepnesses are also discussed.

关键词： parametric rolling nonlinear strip theory cfd method overset grid method

On the Effect of the Rotating Chamber Reverse Speed on the Mixing of SiC Ceramic Particles in a Dry Granulation Process

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Fluid Dynamics & Materials Processing 2021年第2期17卷 487-500页

作者： Dongling Yu Zuoxiang Zhu Jiangen Zhou Dahai Liao Nanxing Wu School of Mechanical and Electronic Engineering Jingdezhen Ceramic InstituteJingdezhen333403China National Engineering Research Center for Domestic&Building Ceramics Jingdezhen333001China

In order to control the accumulation of SiC ceramic particles on the wall of the rotating chamber in the frame of a dry granulation process,the effect of the wall reverse speed on the mixing process is *** particular,an Euler-Euler two-phase flow model is used to analyze the dynamics of both SiC particles and *** numerical results show that by setting a certain reverse rotating speed of the rotating chamber,the accumulation of SiC particles on the wall can be improved,i.e.,their direction of motion in proximity to the wall can be changed and particles can be forced to re-join the granulation *** tests conducted to verify the reliability of the numerical findings,demonstrate that when the reverse rotating speed of the rotating chamber is 4 r/min,the sphericity of SiC particles in the rotating chamber is the highest and the fluidity is the best possible one.

关键词： SiC ceramic dry granulation cfd method accumulate of wall surface rotating chamber reverse speed

Numerical Investigation into the Distributor Design in Radial Flow Adsorber

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Advances in Applied Mathematics and Mechanics 2019年第6期11卷 1436-1460页

作者： Yongliang Chen Yao Li Haiqing Si Bing Wang Haibo Wang Yingying Shen Ziqiang Qin College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106JiangsuChina College of Civil Aviation and Flight Nanjing University of Aeronautics and AstronauticsNanjing 211106JiangsuChina

Air flow distribution in radial flow adsorber was numerically investigated using computational fluid dynamics(cfd)method,which was proved to be applicable to study the problem of non-uniform distribution in radial flow *** showed that the degree of non-uniformity was more serious in desorption process than that is adsorption ***,it was considered that the non-uniform distribution of flow in a radial flow adsorber was mainly manifested in the desorption *** design of distributor parameters can improve the flow distribution in ***,three different structures of distributor and the effect of breathing valve were *** revealed that truncated cone is more effective than tubular and conical distributors in flow *** inserting the truncated cone in central channel,desorption uniformity was increased by 6.56%and the breakthrough time of CO_(2)was extended from 564s to 1138s in the adsorption ***“dead zone”problem at the top of adsorber during the desorption process was solved by opening breathing valve,which prolonged the working life of adsorber and was proved to have less effect on the uniform of airflow.

关键词： cfd method air separation radial flow adsorber adsorption desorption

Dynamic Analysis of Single Pile in Liquefied Soils Considered as Newtonian Fluid

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Open Journal of Geology 2021年第2期11卷 19-37页

作者： Jinjing Sun Xinlei Zhang Zhihua Wang Hongmei Gao Lian Xu The 3rd Geological Brigade of Jiangsu Geology & Mineral Exploration Bureau Nanjing China Urban Underground Space Research Center Nanjing Tech University Nanjing China

Case histories have shown that the liquefaction-induced soil lateral spreading is one of the main causes of damage to pile foundations subjected to seismic loading. Post-liquefaction soil behaves similarly to a viscous fluid. This study investigated the effect of soil lateral spreading on a single pile based on fluid mechanics in which the liquefied soils were treated as Newtonian fluids. A numerical simulation on a single pile embedded in a fully saturated sandy foundation was conducted and compared with shake table tests. The lateral flow effect and the effect of shear strain rate were discussed. After liquefaction, the acceleration of the foundation shows that there are no obvious spikes and finally reaches a stable state. The presented method can predict the pile response better than p-y curve method. A parametric study was performed to explore the effect of several influence factors on pile behaviors. The results show that the pile head displacement decreases and the maximum bending moment at pile bottom increases with the increase of bending stiffness. With the same pile bending stiffness, the displacement and bending moment of pile increase with the increase of soil viscosity and acceleration amplitude.

关键词： Pile Liquefaction-Induced Lateral Spreading Newtonian Fluid cfd method

Semi-submersible Offshore Coupled Motion in Irregular Waves

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Journal of Marine Science 2020年第2期2卷 27-37页

作者： Baoji Zhang Ying Wang College of Ocean Science and Engineering Shanghai Maritime UniversityShanghai201306China

In order to predict the hydrodynamic performance of semi-submersible offshore platform accurately,based on cfd theory,continuous equation and N-S equation as the control equation,RNG type k-εmodel as turbulence model,using the finite difference method to discretize the control equation,using the Semi-Implicit method for Pressure Linked Equation(SIMPLE)algorithm to solve the control equation,using the VOF method to capture the free *** numerical wave tank of irregular wave is established,and the wave force and motion response of the semi-submersible platform under irregular wave are *** on the Jonswap spectrum density function,for a certain area of two irregular waves(South China sea,a-ten-year return period,a-hundred-year return period)sea condition,five wave direction Angle(0°,30°,45°,60°,90°),a total of 10 kinds of conditions of the motion response of semi-submersible platform are simulated,through analysis and comparison of simulation results,the influence law of wave angle,wave period and wave height on platform motion is *** with the experimental values,the results of heave and pitch are close to the experimental data under the sea condition of 2,0 degree wave *** research results in this paper can provide reference for the design and motion response prediction of practical semi-submersible offshore platforms.

关键词： Semi-submersible offshore platform cfd method Irregular waves Motion response Wave force

Analysis and Research on Aerodynamic Characteristics of Quad Tilt Rotor Aircraft

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Advances in Aerospace Science and Technology 2024年第1期9卷 28-39页

作者： Jike Jia Xiaomei Ye Guoyi He Qingjin Huang Zhile Hong Faculty of Flight Engineering Nanchang Hangkong University Nanchang China

For the quad tilt rotor aircraft, a computational fluid dynamics method based on multiple reference frames (MRF) was used to analyze the influence of aerodynamic layout parameters on the aerodynamic characteristics of the quad tilt rotor aircraft. Firstly, a numerical simulation method for the interference flow field of the quad tilt rotor aircraft is established. Based on this method, the aerodynamic characteristics of isolated rotors, rotor combinations at different lateral positions on the wing, and rotor rotation directions under different inflow velocities were calculated and analyzed, in order to grasp their aerodynamic interference laws and provide reference for the design and control theory research of such aircraft.

关键词： Quad Tilt Rotor Aircraft Analysis of Aerodynamic Characteristics cfd method

Analysis of Wave Added Drag and Motion Response of Mid-high-speed Ship against Waves

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Sustainable Marine Structures 2023年第1期5卷 1-10页

作者： Jing Wang Yu Zhou China Institute of Marine Technology and Economy Beijing100081China Jiangsu Shipping College NantongJiangsu226010China

In order to accurately predict the on-wave resistance and responses to hull motions of ships in actual sea conditions,the k-εmethod of the RNG model is adopted on the basis of the unsteady RANS *** two-formula turbulence model deals with the viscous flow,the VOF method captures the free surface,the velocity boundary method makes waves,the artificial damping method is used to eliminate waves,and the nested grid technology is used to deal with the motion response of ships on *** with the 6-DOF motion formula,a three-dimensional numerical wave cell for regular waves is *** one example,taking a KCS Container ship and fishing boat sailing at a mid-high-speed,the increase of wave resistance and motion response at different wavelengths are analyzed,and the simulation results are compared with the experimental value,the content of strip theory in potential flow theory and the panel method to prove the reliability of cfd method in predicting ship motion.

关键词： cfd method Wave added resistance Motion response Numerical pool Numerical simulation