检索结果-内蒙古大学图书馆

numerical visualization of Air Intake Induced by Free Surface Vortex

Journal of Thermal Science 2017年第6期26卷 540-544页

作者： Young Kyu Park Mohan Kumar Dey Yoon Hwan Choi Yeon Won Lee Research Institute of Industrial Science & Technology Pukyong National University Busan Korea Interdisciplinary Program of Biomedical Mechanical and Electrical Engineering Pukyong National University Busan Korea Department of Mechanical Design Engineering Pukyong National University Busan Korea

Free surface vortex control is vital in a pump sump system because the air absorbed by free surface vortex induc- es noise, vibration, and cavitation corrosion on the pumping system. In this study, the change of free surface vor- tex and air absorption in a pump intake has been investigated by the Volume of Fraction （VOF） method with steady multiphase flow model in order to represent the behavior of the free surface vortex exactly. The homoge- neous free surface model is used to apply interactions of air and water. The results show that air intake by the free surface vortex motion can be visualized using the iso-surface of air volume fraction. The vortices make an air column from the free surface to the pump intake. Also, it was found that the flee surface vortex can be controlled by installing curtain walls.

关键词： free surface vortex numerical visualization curtain wall air intake

来源：评论

学校读者我要写书评

暂无评论

numerical visualization by rapid isosurface extractions using 3D span spaces

引用

JOURNAL OF visualization 2008年第3期11卷 189-196页

作者： Hirano, M. Itoh, T. Shirayama, S. Univ Tokyo Sch Engn Kashiwa Chiba 2778568 Japan Ochanomizu Univ Grad Sch Humanities & Sci Bunkyo Ku Tokyo 1128610 Japan Univ Tokyo RACE Kashiwa Chiba 2778568 Japan

In this paper, we focus on visualization of a 3D scalar field composed of volume data by means of semi-transparent multiple isosurface extraction. A new method for displaying semi-transparent multiple isosurfaces will be proposed to fulfill real-time rendering of scalar fields. The proposed method is considered to be an extension of ISSUE, which is a known algorithm to quickly generate isosurfaces. ISSUE uses a 2D span space, where minimum values of computational cells are assigned to the horizontal axis, and maximum values of cells are assigned to the vertical axis. In the proposed algorithm, computational cells are placed onto a 3D span space. The third axis is the distance from the viewpoint. The proposed algorithm can quickly search for the cells intersecting with isosurfaces using the span space in back-to-front order and can realize representation of semi-transparent multiple isosurfaces.

关键词： numerical visualization large-scale 3D data scalar field isosurface real-time rendering

来源：评论

学校读者我要写书评

暂无评论

numerical visualization of two-phase plume formation in a stratification flow environment

引用

visualization AND IMAGING IN TRANSPORT PHENOMENA 2002年第1期972卷 285-291页

作者： Chen, BX Nishio, M Song, YC Someya, S Akai, M AIST EAST RITE Tsukuba Div RITERes Inst Innovat Technol Earth Tsukuba Ibaraki 3058564 Japan Natl Inst Adv Ind Sci & Technol Res Inst Energy Utilizat Tsukuba Ibaraki Japan

Evolution of two-phase plumes driven by air bubble buoyancy in a stratification ambient in a rectangular tank is visualized numerically by means of two-phase flow theory and large-eddy simulation technology. With a focus on the discrete nature of the buoyant dispersed phase and the role of momentum exchange between two phases in plume formation, we investigated the phenomena of mass entraining-in and peeling-out for continuous phase plume, which may result from a complicated and intricate interplay with phase interaction and dynamic stability of the stratification ambient, respectively. numerical simulations show that although mass entraining-in and peeling-out appear to be distinguished entirely in the vertical direction, they interact or couple locally within inner of the plume and present a discontinuity in nature. The numerically visualized three-dimensional density field also indicates the same plume characteristics.

关键词： two-phase plume numerical visualization LES stratification

来源：评论

学校读者我要写书评

暂无评论

numerical visualization of Free Surface Oscillation Predicted with Arbitrary Lagrangian-Eulerian Method

引用

Journal of visualization 2000年第3期3卷 237-244页

作者： Ushijima, S. Dept. of Global Environ. Engineering Kyoto University Kyoto-shi 606-8501 Japan

A numerical prediction method has been proposed to predict non-linear free surface oscillation in a three-dimensional container. The fluid motions are numerically predicted with NavierStokes equations discretized in a Lagrangian scheme with sufficient numerical accuracy. The profile of a free surface is precisely represented with three-dimensional body-fitted coordinates (BFC), which are regenerated in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) formulation. The computational method was applied to non-linear sloshings and transitions from sloshing to swirling motions. The predicted free surface motions were visualized as sequential image files and animations to understand their dynamic futures.

关键词： Arbitrary Lagrangian-Eulerian Body-fitted coordinates Moving boundary Non-linear sloshing numerical visualization

来源：评论

学校读者我要写书评

暂无评论

Holographic interferometric and numerical visualization of three-dimensional unsteady shock wave interactions

Holographic interferometric and numerical visualization of t...

引用

23rd International Congress on High-Speed Photography and Photonics

作者： Timofeev, EV Takayama, K Voinovich, PA Sislian, J Tohoku Univ Inst Fluid Sci Shock Wave Res Ctr Aoba Ku Sendai Miyagi 9808577 Japan Ctr Adv Technol St Petersburg 199226 Russia Univ Toronto Inst Aerosp Studies Downsview ON M3H 5T6 Canada

ISBN: (纸本)0819429759

Recent results of observation of three-dimensional (3-D) unsteady shock wave reflections are presented. The experiments are carried out using a diaphragmless shock tube in which shock waves are produced by a quickly opening piston valve which separates a high pressure driver gas from a low pressure test gas. This mechanism allows to create shock waves with a higher degree of repeatability than those obtained by conventional shock tubes in which shock waves are generated by rupturing diaphragms. Double exposure diffuse halographic interferometry is used for optical visualization. Instead of using diffusive object beams, collimated object beams are diffused by their reflection from the shock tube wall and the model painted with fluorescent paint. In addition, the time interval between two exposures is set to about 1 mu s. Hence 3-D shock wave patterns are clearly observable. The experiment is supplemented by numerical visualizations using a 3-D adaptive unstructured Euler code working on the Gray C-90 supercomputer platform, and then EnSight postprocessor is used to create numerical images. Two cases are examined: shock wave reflection from an inclined cylinder, and shock wave interaction with a corner formed by the intersection of two wedges at 90 degree.

关键词： holographic interferometry shock tube numerical visualization 3-D unsteady hows shock wave

来源：评论

学校读者我要写书评

暂无评论

numerical flow visualization of first cycle and cyclic motion of a rigid fling-clapping wing

引用

JOURNAL OF visualization 2006年第4期9卷 381-391页

作者： Chang, J. W. Sohn, M. H. Hankuk Aviat Univ Dept Aeronaut Sci & Flight Operat Goyang 412791 Kyeonggi South Korea Korea Air Force Acad Dept Aerosp Engn Chungwon 363849 Chungbuk South Korea

A flow visualization of the two-dimensional rigid fling-clap motions of the flat-plate wing is performed to get the knowledge of fling-clapping mechanism that might be employed by insects during flight. In this numerical visualization, the time-dependent Navier-Stokes equations are solved for two types of wing motion;'fling followed by clap and pause motion' and,cyclic fling-clapping motion'. The result is observed regarding the main flow features such as the sequential development of the two families of separation vortex pairs and their movement. For the 'fling followed by clap and pause motion', a strong separation vortex pair of counterrotation develops in the opening between the wings in the fling phase and they then move out from the opening in the following clap phase. For 'the cyclic fling-clapping motion', the separation vortex pair developed in the outside space in the clap phase move into the opening in the following fling phase. The separation vortex pair in the opening developed in the fling phase of the cyclic motion is observed to be stronger than those of the 'fling followed by clap and pause motion'. Regarding the strong fling separation vortex and the weak clap separation vortex above it in the opening, the flow pattern of the fling phase of the cyclic fling and clap motion is different to that of the fling phase of the first cycle. The flow pattern of the third cycle of the cyclic fling-clapping motion is observed to be almost same as that of the second cycle. Therefore, a periodicity of the flow pattern is established after the second cycle.

关键词： fling-clap motion first cycle Navier-Stokes equation insect flight numerical visualization separation vortex

来源：评论

学校读者我要写书评

暂无评论

An investigation into the validation of numerical solutions of complex flowfields

引用

JOURNAL OF COMPUTATIONAL PHYSICS 1999年第2期151卷 479-497页

作者： Jiang, Z Takayama, K Tohoku Univ Inst Fluid Sci Shock Wave Res Ctr Aoba Ku Sendai Miyagi 9808577 Japan

Three cases, including a two-dimensional, an axisymmetric, and a three-dimensional flowfield, were studied to demonstrate the effectiveness and reliability of a method proposed for validation of numerical solutions of complex flowfields. Images of these flowfields were first constructed from numerical solutions based on the principle of experimental flow visualization, and then compared directly with experimental interferograms. Because both experimental and numerical results are of identical physical representation, agreement between them can be evaluated effectively by examining characteristic flow structures of the flowfields as well as comparing differences in density. An efficient algorithm for three-dimensional density integration was also proposed to replace the conventional one that is computationally expensive. The study shows that reliable validation can be achieved in this way because it allows a direct comparison between numerical and experiment results without any loss of accuracy in either of them. The validation method is highly recommended for three-dimensional flowfields where quantification of images from experimental flow visualization is very difficult or impossible. (C) 1999 Academic Press.

关键词： CFD validation numerical visualization holographic interferogram three-dimensional density integration

来源：评论

学校读者我要写书评

暂无评论

Application issues of the streamline, heatline and massline for conjugate heat and mass transfer

引用

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2007年第1-2期50卷 320-334页

作者： Zhao, Fu-Yun Liu, Di Tang, Guang-Fa Hunan Univ Coll Civil Engn Changsha 410082 Hunan Peoples R China

Functions and lines have been extensively used to visualize two-dimensional fluid, heat and mass transportation structures. However, some ambiguities related to streamlines, heatlines and masslines still exist, especially for conjugate heat and mass transfer in anisotropic media. Present work aims to clarify these issues from numerical viewpoints, mainly including diffusion coefficient of transportation function at the interface of different media, different numerical approaches for solving visualization functions, non-dimensional forms of heat-function and massfunction matching the spatial Nusselt and Sherwood numbers. The numerical procedures and code routines for the primitive conserved variables and the functions are illustrated through visualizing fluid, heat and solute transportations of double diffusive natural convection in square enclosures with massive walls or center-inserted body. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： numerical visualization integration method Poisson method conjugate heat and mass transfer

来源：评论

学校读者我要写书评

暂无评论

numerical simulation of biomagnetic fluid in a channel with thrombus

引用

JOURNAL OF visualization 2002年第2期5卷 187-195页

作者： Haik, Y Chen, CJ Chatterjee, J FSU FAMU Coll Engn Tallahassee FL 32310 USA

Biomagnetic fluid dynamics is the study of the interaction of biological fluids with an applied steady magnetic field. Recently, several medical applications begin to utilize magnetic labeling of specific cells and targeted drug delivery using magnets. The magnetically labeled cells and the drug encapsulates are usually loaded in the blood stream and are directed toward a specific site by use of a magnet. In this paper, numerical simulation of biomagnetic fluid in the presence of a thrombus when exposed to magnetic field is presented. The finite analytic method is used to obtain the numerical simulation. It is found that the magnetic force causes a drastic change in the fluid behavior and the friction coefficient increases as the magnetic field strength increases.

关键词： non-linear sloshing moving boundary body-fitted coordinates arbitrary Lagrangian-Eulerian numerical visualization

来源：评论

学校读者我要写书评

暂无评论

numerical simulation of flow around a circular cylinder with curved sectional grooves

引用

JOURNAL OF visualization 2007年第2期10卷 179-186页

作者： Yamagishi, Y. Oki, M. Kanagawa Inst Technol Dept Engn Mech Kanagawa 2430292 Japan Tokai Univ Sch High Technol Human Welf Shizuoka 4100395 Japan

In a circular cylinder with uniform flow, a sudden decrease in the drag force occurs at a high Reynolds numbers;however, it is known that the same phenomenon occurs at a lower Reynolds number in the case where there exist grooves or roughness on the circular cylinder surface. To clarify the flow characteristics around a circular cylinder in the case of changing the shape of grooves we analyzed the drag coefficient, lift coefficient, turbulent kinetic energy, vorticity and pressure by applying the RNG k-epsilon turbulent model. The shapes of the grooves were arced, triangulated and curved. The results showed that the separation point for a circular cylinder with curved sectional grooves shifts to the most downstream side and the drag coefficient becomes the smallest among circular cylinders with grooves.

关键词： circular cylinder with grooves curved sectional grooves flow characteristics drag coefficient numerical visualization

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：