A virtual globe-based three-dimensional dynamic visualization method for gas diffusion

2019 ◽  
Vol 111 ◽  
pp. 13-23 ◽  
Author(s):  
Ruozhen Cheng ◽  
Jing Chen ◽  
Ming Cao
2019 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Jiafeng Shi ◽  
Jie Shen ◽  
Zdeněk Stachoň ◽  
Yawei Chen

<p><strong>Abstract.</strong> With the increasing number of large buildings and more frequent indoor activities, indoor location-based service has expanded. Due to the complicated internal passages of large public buildings and the three-dimensional interlacing, it is difficult for users to quickly reach the destination, the demand of indoor paths visualization increases. Isikdag (2013), Zhang Shaoping (2017), Huang Kejia (2018) provided navigation services for users based on path planning algorithm. In terms of indoor path visualization, Nossum (2011) proposed a “Tubes” map design method, which superimposed the channel information of different floors on the same plane by simplifying the indoor corridor and the room. Lorenz et al (2013) focused on map perspective (2D/3D) and landmarks, developed and investigated cartographic methods for effective route guidance in indoor environments. Holscher et al (2007) emphasized using the landmark objects at the important decision points of the route in indoor map design. The existing studies mainly focused on two-dimensional plane to visualize the indoor path, lacking the analysis of three-dimensional connectivity in indoor space, which makes the intuitiveness and interactivity of path visualization greatly compromised. Therefore, it is difficult to satisfy the wayfinding requirements of the indoor multi-layer continuous space. In order to solve this problem, this paper aims to study the characteristics of the indoor environment and propose a path visualization method. The following questions are addressed in this study: 1) What are the key characteristics of the indoor environment compared to the outdoor space? 2) How to visualize the indoor paths to satisfy the users’ wayfinding needs?</p>


2020 ◽  
Vol 99 (sp1) ◽  
pp. 85
Author(s):  
Bo Ai ◽  
YunHang Xia ◽  
ZhiGang Li ◽  
FanLin Yang ◽  
Min Ji

Author(s):  
Hiroto Namihira

This chapter proposes a new educational methodology for theoretical contents. It aims to effectively transmit theoretical content meanings. Here, the effects of content visualization enhance the transmission of meaning. By processing visual information, the human brain can immediately understand the mutual relationships between elements in addition to the whole meaning. Comprehension becomes increasingly effective when movement is added to static information. The new educational methodology proposed here is based on such visualization. It is called “The Dynamic Visualization Method.” It is designed so students can visually set allowable conditions before processing them. This selective freedom enables students to extract their hidden leaning interests. Mathematical processes were used to verify the effectiveness of this methodology. A variety of items were thus adopted ranging from the elementary-school to university levels. The contents of those items are visualized in this chapter. The educational effects are then discussed.


2012 ◽  
Vol 512-515 ◽  
pp. 1509-1514
Author(s):  
Lin Fa Peng ◽  
Dian Kai Qiu ◽  
Pei Yun Yi ◽  
Xin Min Lai

The assembly force in a proton exchange membrane fuel cell (PEMFC) stack affects the characteristics of the porosity and electrical conductivity. Generally, the stack is assembled at room temperature while it’s operated at about 80 °Cor even higher. As a result, the assembly pressure can’t keep constant due to thermal expansion. This paper focuses on the contact pressure between membrane electrode assembly (MEA) and bipolar plates in real operations. A three-dimensional finite element (FE) model for the assembly process is established with coupled thermal-mechanical effects. The discipline of contact pressure under thermal-mechanical effect is investigated. A single cell stack is fabricated in house for the analysis of contact pressures on gas diffusion layer at different temperatures. The results show that as the temperature increases, contact pressure increases due to thermal expansion. It indicates that the influence of thermal expansion due to temperature variation should be taken into consideration for the design of the stack assembly process.


Author(s):  
C. E. Damia´n-Ascencio ◽  
A. Herna´ndez Guerrero ◽  
J. A. Escobar Vargas ◽  
S. Cano-Adrade ◽  
F. Elizalde Blancas

The present work shows a three-dimensional numerical simulation of a Single Proton Exchange Membrane Fuel Cell (PEMFC) with a constructal-based pattern as a gas distributor. The models are classified according to the proposed angle and bifurcation level. The numerical model considers a complete solution of the Navier-Stokes equations, the species transport equation and two potential field equations; the model is solved using a finite-volume technique assuming isothermal and steady state conditions. The three-dimensional simulation includes nine control volumes: two current collectors, two flow channels, two gas diffusion layers, two catalyst layers and a membrane between the two catalyst layers. The results show that larger values of current density can be obtained in order if the bifurcation levels are increased. This suggests that a better performance is reached when the structure is closer to those structures found in the natural world.


2019 ◽  
Vol 577 ◽  
pp. 123988
Author(s):  
Guozheng Zhi ◽  
Zhenliang Liao ◽  
Wenchong Tian ◽  
Xin Wang ◽  
Juxiang Chen

2006 ◽  
Vol 4 (1) ◽  
pp. 84-87 ◽  
Author(s):  
Stefan Griesser ◽  
G. Buchinger ◽  
T. Raab ◽  
D. P. Claassen ◽  
Dieter Meissner

Three dimensional (3D) computer aided X-ray tomography (CT) has proven to be an extremely useful tool in developing our own as well as in examining commercially available solid oxide fuel cells. The results of 3D-CT measurements became very important for understanding the functionality of our first generation and improving the development of our second fuel cell generation. Also geometrical measurements, especially the roundness and the straightness of the tube, can be evaluated, both critical parameters when the stack is heated and mechanical stress has to be avoided. By using this technique the structure of the first generation cells proved to be of insufficient quality. Problems like the variation in thickness of the electrolyte tube as well as the homogeneity in thickness of the electrodes deposited can easily be detected by this nondestructive technique. Microscopic investigations of this problem of course provide equal results, but only after cutting the samples in many slices and many single measurements of different areas of the fuel cell. Using cells with inhomogeneous thickness of course results in drastic variations of the current densities along a single cell. Electrolyte layers that are too thick will result in power loss due to the increased resistance in the ionic conductivity of the electrolyte. If the electrolyte of an electrolyte supported cell is too thin, this can cause mechanical instability. Problems can also occur with the leak tightness of the fuel cell tube. Gas diffusion through the electrode layer can become a problem when the thickness of the electrode layer is too high. On the other hand, if the layers are too thin, the result can be a discontinuous layer, leading to a high electrical series resistance of the electrode. Besides determining the thickness variations also the porosity of the electrolyte needs careful attention. Larger cavities or shrink holes form insulating islands for the ion-stream and are therefore limiting the ionic conductivity. They are also diminishing the mechanical stability and provide problems for depositing a closed electrode film in electrode supported cells.


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