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Journal of Hydrodynamics 2010年第1期22卷 1-8页

作者： XU Zu-xin WEI Zhong YIN Hai-long HUANG Li-hui State Key Laboratory of Pollution Control and Resource Reuse Tongji University Shanghai 200092 China College of Environmental Science and Engineering Shandong University Jinan 250100 China

A Natural Ecological Wastewater Treatment System （NEWTS） is usually built on natural terrain with necessary topography modification to improve water flowing route and pattern, and then the topography modified NEWTS should also have a reasonable water storage volume and hydraulic retention time so as to achieve the anticipated water purification effect. In this study, the dynamic mesh technique based on the finite element method and element storativity coefficients was presented to develop a two-dimensional hydrodynamic and water quality model, which was used to optimize the design of NEWTS under the dynamic land-water boundary due to various water storage volume. The models were employed in the optimized design of NEWTS from a large abandoned coal mine, which purifies the polluted water flowing into a large water storage lake, as part of the East Route South-to-North Water Transfer Project in China. Specifically, the natural topography modification scheme was presented, and further, a reasonable water storage volume and hydraulic residence time was obtained, based on the reasonable estimation of roughness coefficient and pollutant removal rate of the NEWTS with phragmites communis.

关键词： ecological wastewater treatment dynamic mesh hydrodynamic model water quality model abandoned coal mine

Numerical study on DPM dispersion and distribution in an underground development face based on dynamic mesh

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International Journal of Mining Science and Technology 2020年第4期30卷 471-475页

作者： Ping Chang Guang Xu Jinxin Huang WA School of Mines MineralsEnergy and Chemical EngineeringCurtin UniversityKalgoorlieWA 6430Australia Department of Mining Engineering Missouri University of Science and TechnologyRollaMO 65409USA

In 2012,the International Agency for Research on Cancer(IARC)classified diesel particulate matter(DPM)as a carcinogen to human.With the increased usage of diesel equipment in underground mines,miners have a high risk of over-exposure to DPM,which has drawn many concerns from the public.This study used computational fluid dynamics(CFD)to analyse the DPM dispersion and concentration distribution characteristics in an underground development face based on an onsite experiment.The DPM emitted from a moving loader under a forcing auxiliary ventilation system was simulated.The motion of the load-haul-dump(LHD)in the tunnel was represented by a dynamic mesh method.The species transport approach was applied to study the DPM behaviours.High DPM concentration zones were then identified based on the simulation results.The results could provide guidelines for work practices and be helpful to an optimum auxiliary ventilation design to reduce underground miner exposure.

关键词： Diesel particulate matter Underground mines Ventilation Computational fluid dynamics dynamic mesh

A moving interior boundary method fitted dynamic mesh for the simulation of flow through moving bodies

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A moving interior boundary method fitted dynamic mesh for th...

Performance of large-diameter pneumatic down-the-hole (DTH) hammers: A focus on influences of the hammer structure

The 2011 International Conference on Key Engineering Materials and Computer Science(KEMCS 2011)

作者： Mao Deng Zongming Wang Chunxue Zhang College of Electromechanical Engineering China University of Petroleum Dongying cityShandong provinceP.R.China

We present an easy approach to obtain the dynamic flow field with a moving body insideInstead of popular interface boundaries, the interior boundaries were applied as moving parts, which made separated computation volumes a default-continuum meanwhileWith the combination use of UDF and dynamic mesh model, the numerical technique was tested and validated by simulating flow through moving screen, a kind of porous materialThe pressure and velocity contours obtained clearly showed the changing behaviors of the flow while passing through a moving porous material, and clarified the influence posed by the movement of its frameThe method is used for the simulation of the flow with a moving body inside.

关键词： CFD dynamic mesh moving body porous material simulation

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Petroleum Science 2023年第4期20卷 2399-2412页

作者： Pin-Lu Cao Hong-Yu Cao Jin-E Cao Cheng-Da Wen Bao-Yi Chen Shan-Shan Yao College of Construction Engineering Jilin UniversityNo.938 Ximinzhu StrChangchunJilin130061China

Pneumatic down-the-hole (DTH) hammer has been extensively used in air drillings through hard and ultra-hard geological formations. Numerical modeling can offer close observation on the working behaviors by visualizing internal pressure status as well as provide reliable performance predictions for large-diameter DTH hammers to which conventional empirical and experimental approaches cannot be applied. In this study, CFD simulations coupled with dynamic meshing are utilized to simulate the air flow and piston movement inside the large-diameter DTH hammers. The numerical modeling scheme is verified against a theoretical model published in literature. Effects of structural parameters on hammer performance, including piston mass, piston upper-end diameter, piston groove diameter, and lengths of intake and exhaust stroke in both front and rear chambers, are analyzed in detail by virtue of sets of numerical simulations. The simulations suggest that changing the intake stroke of front chamber has a negligible influence on hammer performance while increasing the piston groove would lower all the four indicators of hammer performance, including impact energy, impact frequency, maximum stroke, and air consumption rate. Changing the other structural parameters demonstrates mixed effects on the performance indicators. Based on the numerical simulations, a large GQ-400 DTH hammer has been designed for reduced air consumption rate and tested in a field drilling practice. The air drilling test with the designed hammer provided a penetration rate 1.7 times faster than that of conventional mud drilling.

关键词： Pneumatic down-the-hole(DTH)hammer Computational fluid dynamics dynamic mesh Gas turbulent flow Piston impact performance

Numerical Simulation of Liquefaction-Induced Settlement of Existing Structures

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Journal of Earth Science 2023年第2期34卷 339-346页

作者： Wuwei Mao Wei Li Rouzbeh Rasouli Naveed Ahmad Hu Zheng Yu Huang Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of Geotechnical and Underground Engineering Ministry of EducationTongji UniversityShanghai 200092China Jacobs TorontoOntario M2J 1R3Canada Department of Civil Engineering University of Engineering and TechnologyTaxila 47050Pakistan

This study presents a numerical approach for assessment of the structure settlement problems in liquefied soils.The fluid dynamics theory was applied to model the liquefied soils and the rigid body dynamics theory was applied to compute the structure’s translational and angular motions in six degrees of freedom.The dynamic mesh method was applied to modify the deformed mesh due to structure settlement.Shaking table tests were carried out to reproduce the structure’s subsidence behavior and provide validation for the numerical simulations.Results show that the settlement of the structure occurred most rapidly at the very beginning of liquefaction,and then it decreased gradually.Main structure settlements occurred within 10 s after liquefaction.Regarding different structure weights,structure with larger weight yielded larger amount of settlement and higher peak settlement velocity.The results obtained in this study are beneficial for assessment of structure settlement problems in liquefaction prone areas.

关键词： liquefaction computational fluid dynamics viscous dynamic mesh shaking table test engineering geology

Delaunay graph-based moving mesh method with damping functions

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Chinese Journal of Aeronautics 2018年第11期31卷 2093-2103页

作者： Yibin WANG Ning QIN Ning ZHAO College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Department of Mechanical Engineering The University of Sheffield

The fluid–structure interaction and aerodynamic shape optimization usually involve the moving or deforming boundaries, thus the dynamic mesh techniques are the key techniques to cope with such deformation. A novel dynamic mesh method was developed based on the Delaunay graph in this paper. According to the Delaunay graph, the mesh points were divided into groups. In each group, a factor ranging from 0 to 1 was calculated based on the area/volume ratio. By introducing a proper function for this factor, this method can control the mesh quality with high efficiency. Several test cases were compared with other dynamic mesh methods regarding mesh quality and CPU time, such as radial basis function method and Delaunay graph mapping method.

关键词： Delaunay graph mapping dynamic mesh Grid deformation mesh Moving mesh

Numerical Study of Blast Effects impacting on the Vehicles in Tunnel with dynamic mesh Model

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Numerical Study of Blast Effects impacting on the Vehicles i...

NUMERICAL SIMULATION OF FLOW AND HEAT TRANSFER CHARA-CTERISTICS OUTSIDE A PERIODICALLY VIBRATING TUBE

The 4th Across-strait Workshop on Shock Wave/Vortex Interaction

作者： Chang-hsien Tai Jyh-tong Teng Shi-wei Lo Uzu-kuei Hsu Department of Vehicle Engineering Pingtung University of Science and Technology Department of Mechanical Engineering Chung Yuan Christian University

The blast effects caused by the explosion generate serious damage during propagation and interaction.A great injuries and deaths incident incurred because of explosion in petrochemical industry,firecracker factory and car-mounted gas,etc.around the world in recent years.Especially, the 911 crashes in 2001,Bali’s series of explosion in 2002,and Benazir Bhutto assassinated in

关键词： blast wave CFD dynamic mesh overpressure reflection tunnel vehicles

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Journal of Hydrodynamics 2008年第5期20卷 629-636页

作者： JIANG Bo TIAN Mao-cheng LENG Xue-li TANG Yu-feng PAN Ji-hong School of Energy Source and Power Engineering Shandong University Jinan 250061 China

Fluid flow and heat transfer characteristics outside a vibrating tube were numerically simulated by the dynamic mesh method. The mechanism of heat transfer enhancement via periodic vibration of the tube was explored by using the field synergy principle. It is found that the field synergy angle between fluid velocity vector and temperature gradient vector for a periodically vibrating tube is significantly smaller than that for a stationary tube, and it changes approximately according to the sinusoidal law in a vibration period. The effect of time phase of the vibration on the field synergy angle and convective heat transfer coefficient were also discussed. Results indicate that the vibration can enhance heat transfer and this effect is more remarkable when time phase angle ranges between 50° and 1400 in a half period. Especially when the time phase angle is 90°, the average field synergy angle outside the tube reaches the minimum, which leads to the best heat transfer performance.

关键词： heat transfer enhancement dynamic mesh vibration field synergy Computational Fluid dynamics （CFD）

A NEW METHOD FOR NUMERICAL SIMULATION OF TWO TRAINS PASSING BY EACH OTHER AT THE SAME SPEED

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Journal of Hydrodynamics 2010年第5期22卷 697-702页

作者： ZHAO Xiao-li SUN Zhen-xu School of Aerospace Tsinghua University Beijing China State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Beijing China

A new method is proposed to numerically simulate problems of trains passing by each other at the same speed, and is implemented in UDF language of commercial software Fluent. Because only a half of the computational domain is required and the dynamic mesh technique is avoided, the computational efficiency is greatly improved. A two-dimensional test case is used for validation, which shows that the flow field and the pressure wave during the train-passing events can be correctly calculated by this new method. This method can be easily extended to three-dimensional simulations, to deal with practical problems.

关键词： trains passing by each other rotational symmetry dynamic mesh pressure wave

A numerical analysis of the influence of the cavitator's deflection angle on flow features for a free moving supercavitated vehicle

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Journal of Hydrodynamics 2014年第5期26卷 697-705页

作者：陈鑫鲁传敬陈瑛曹嘉怡 Department of Engineering Mechanics Shanghai Jiao Tong University MOE Key Laboratory of Hydrodynamics Shanghai Jiao Tong University

When a high-speed cavitated weapon moves under water, the flow properties are important issues for the sake of the trajectory predication and control. In this paper, a single-fluid multiphase flow method coupled with a natural cavitation model is proposed to numerically simulate the flee moving phase of an underwater supercavitated vehicle under the action of the external thrust. The influence of the cavitator＇s deflection angle ranging from -3~ to 3~ on the cavity pattern, the hydrodynamics and the underwater trajectory is investigated. Based on computational results, several conclusions are qualitatively drawn by an analysis. The deflection angle has very little effect on the cavity pattern. When the deflection angle increases, the variation curves of the vertical linear velocity, the lift coefficient and the pitching moment coefficient become flatter. In the phase of the second natural cavitation, at a same time, the greater the deflection angle is, the lower the drag and the lift coefficients will be and the higher the pitching moment coefficient becomes. At the finishing time of the free moving phase, when the deflection angle lies in the small range of -1~ - 1~, the position of the center of mass and the pitching angle of the vehicle are more close to each other. However, when the deflection angle is less than -1° or greater than 1°, the position of the center of mass and the pitching angle change greatly. Ifa proper deflection angle of the cavitator is adopted, the underwater vehicle can navigate in a pseudo-fixed depth.

关键词： cavitation multiphase underwater trajectory dynamic mesh