A Numerical Simulation of VOCs Distribution in Indoor Environment of a Dormitory

2014 ◽  
Vol 548-549 ◽  
pp. 650-654
Author(s):  
Sun Bin ◽  
Zhi Hui Yang

This document utilizes CFD simulation method to confirm the distribution of a new dormitory under the condition of natural ventilation and get the visible result and analyses the result of simulation and monitor. Because of the sealing of the room is nice, the result of the simulation value well agree with the true monitor value. By use of CFD simulation method the detailed result of indoor velocity field and pollutant concentration can be get easily. This document provides a method and theory to do further research on indoor pollutant concentration of different conditions, such as different exhaust system, different exhaust volume and different pollutant resource location.

2012 ◽  
Vol 482-484 ◽  
pp. 2592-2595 ◽  
Author(s):  
Zhong Hua Tang ◽  
Ri Chao Liu ◽  
De Bao Lei

Through FLUENT numerical simulation, this paper is aimed on studying the influence of outdoor wind environment on indoor environment. We found that building height, building layout format and opening format in the wall are significant impacted on indoor natural ventilation. At the three-fourth height of building, if the building layout and housing opening is stagger, it can get high-quality indoor natural ventilation and more evenly indoor wind field.


2011 ◽  
Vol 361-363 ◽  
pp. 1056-1060 ◽  
Author(s):  
Bao Lin ◽  
Xue Ting Wang ◽  
Xiao Hu

Because of the relatively narrow space and high density distribution of the passengers, the bus interior environment deteriorates in summer. Natural ventilating introduces a fresh natural freeze, provides the bus interior with appropriate distribution of air supply temperature and velocity field. Making good use of natural ventilation is an operating strategy ideal for improving passengers’ satisfaction, which is considered as an environmental friendly and cost effective approach. Based on CFD numerical simulation, with a whole-domain approach, this paper predicts air flow and thermal comfort in naturally ventilated bus. The outside and inside airflow is modelled simultaneously and within the same computational domain. The thermal environment in different parts of the bus interior is compared. Different vehicle velocities and conditions of windows are taken into account, analysis are made regarding to the effect of both of them on the interior thermal comfort. The result shows, air disturbance at the bus rear parts are intenser than the other parts with better thermal satisfaction; the quality of air flow in different parts makes the temperature difference in bus achieve as high as 3°C; the use of roof openings distributes the temperature more evenly.


2021 ◽  
Vol 13 (18) ◽  
pp. 10433
Author(s):  
Gloria Alexandra Ortiz Rocha ◽  
Maria Angelica Pichimata ◽  
Edwin Villagran

The use of protected agriculture structures in tropical and subtropical countries is the main alternative for intensification of agricultural production selected by producers. In general, in these regions, passive and plastic-covered structures predominate, with natural ventilation as the only method of climate control. This phenomenon has been widely studied in different types of structures using computational fluid dynamics (CFD) simulation. Therefore, this review aimed to collect and analyze the publications generated in this field of knowledge between 2010 and 2020. The search for information included the main academic databases available on the web and the analysis was carried out using bibliometric techniques, from which it was possible to identify details inherent to the scientific production, such as countries of origin, main authors, journals, and citations. Likewise, a detailed breakdown of the relevant technical information of the three phases of numerical simulation, such as preprocessing, processing, and postprocessing, was carried out. A compilation of 118 papers published in 65 journals, written by 256 authors, originating from 24 countries was achieved, where it was evident that Mexico and Colombia were the countries with the highest scientific production in the last decade. These papers analyzed, together, a total of 17 different types of structures where polyethylene-covered greenhouses predominated, with steady state simulations, for daytime climate conditions and without the presence of crops. Within the current and future research trends, the predominance of studies analyzing passive climate control methods, new models of insect-proof mesh-house structures, and, finally, studies focused on the structural analysis of greenhouses was found.


2017 ◽  
Vol 24 (s2) ◽  
pp. 172-180
Author(s):  
Shuzheng Sun ◽  
Wenlei Du ◽  
Hui Li

Abstract The tumblehome hull adopts some novelty designs such as low-tumblehome freeboard and wave-piercing bow. The new form design makes the ship have many special hydrodynamic performances. Especially the green water of tumblehome hull is different from that of hulls with flare free board. Green water is a strong nonlinear phenomenon of ship-wave interaction, the variation of free surface of liquid is complicated, and there are still some difficulties to solve green water problems well with numerical simulation method. In this paper firstly the motion responses of the tumblehome hull was calculated based on 3D potential theory, and then the dam-break flow model was used to calculate green water height and pressure distribution. According to the result of numerical simulation, some typical working conditions are chosen for 3D CFD simulation using RANS method. The results of numerical simulation methods are compared with the experimental results measured in towing tank. The influence of different ship form parameters and wave parameters to the green water of tumblehome hull is analyzed, and some regularities of green water on tumblehome hull in regular waves are summarized.


2019 ◽  
Vol 272 ◽  
pp. 01017
Author(s):  
Liu Yun-ya ◽  
Yu-chen Yang ◽  
Ya-wen Yang

This paper first introduces the basic theory of CFD method, including basic control equations, finite volume method, control equation solving algorithm and turbulence model selection. Second, based on OpenFOAM, an open-source fluid mechanics software, a numerical simulation method of vertical axis tidal turbine was proposed by using k-ω SST turbulence model and PIMPLE algorithm. The hydrodynamic characteristics of the vertical axis turbine were studied, and the calculation results were compared with experiments. The higher consistency proves the feasibility of the numerical simulation method proposed in this paper. Finally, the influence of inlet turbulence on numerical simulation was explored, and a set of effective CFD simulation strategies was concluded, which provided a valuable reference for future CFD simulation and research on vertical axis tidal turbines.


2020 ◽  
Vol 239 ◽  
pp. 22005
Author(s):  
Bo Zhou ◽  
Rui Yan ◽  
Xiaohan Yu ◽  
Yang Zou ◽  
Shihe Yu ◽  
...  

A numerical simulation program for the dynamic distribution of krypton and xenon with flow and on-line removal function was established for primary loop system of molten salt reactor(MSR) Based on Mathe-matica7.0.The simulation results of the static burnup was compared with ORIGEN-S program, and the deviation is less than 10%, which is in good agreement.The distribution and dynamic characteristics of krypton and xenon in the primary loop system were analyzed under the flow regionalization and online removal model.The results show that,the static burnup model underestimates the total 135Xe activity about 6.61% in the system, and the total activity of krypton and xenon in the system is underestimated by about 1.46%.Under the maximum removal fraction, the total activity of krypton and xenon in the exhaust gas system is 1.84×1016Bq, of which 83mKr, 85mKr, 87Kr, 88Kr, 133Xe, 135Xe and 138Xe account for about 95.6%.The total activity of krypton and xenon in the primary loop system is 2.64×1014Bq, of which 138Xe, 135mXe, 134mXe, 87Kr and 83mKr account for about 93.6%.The numerical simulation method and the conclusion consistent with the actual physical laws.Dynamic distribution, evolution and migration characteristics of krypton, xenon and these precursor in the primary loop in the molten salt can be simulated more accurately compared to static burnup model.The analysis results can provide a theoretical basis for the management scheme of airborne source termsthe cooling design of the radioactive exhaust system and the source term analysis in accident conditions for the molten salt reactor.


2014 ◽  
Vol 580-583 ◽  
pp. 2447-2451
Author(s):  
Zhi Yong Wang ◽  
Shun Fu Yang ◽  
Chang Rong Liu ◽  
Tian Yu Zhang ◽  
Na Cui

With the promotion of building energy conservation, many residential areas are closely link with energy saving in design phase, and natural ventilation becomes the key to reduce building energy consumption. Thus, house design and building distribution of residential district is particularly important. Computational fluid dynamics (CFD) get rapid development in recent 20 years, especially in architectural design. This text established a model of part of a residential district in Zhuzhou based upon ANSYS FLUENT CFD software, and used numerical simulation method to simulate the condition of indoor natural ventilation under typical summer climate when the doors and windows of buildings were opened. The distribution regularities of indoor velocity field and pressure field and etc have been gotten. These data provide a theoretical basis to evaluate the building distribution of residential area.


2021 ◽  
pp. 1420326X2110051
Author(s):  
Le Wang ◽  
Wen-Xin Tian ◽  
Xiu-Yong Zhao ◽  
Chuan-Qing Huang

The air flow and pollutant concentration fields in a street canyon affected by trees could affect the comfort and health of residents. At present, the description of the non-uniform/discontinuous distribution of leaves is difficult. In this study, the leaf distribution in the canopy was characterized by establishing non-continuous (uniform/random) algorithm based on a numerical simulation method, and the effects of canopy properties including, height, porosity and uniform/random leaf distribution, on the airflow and pollutant concentration fields in urban street canyons were investigated. The position of the tree canopy was found to directly affect the airflow field form and the air velocity distribution in the street canyon at low inflows. The average air velocity in the street canyon could be reduced significantly when the top of the tree canopy is near the top of the street canyon. The air velocity and pollutant concentration in the street canyon would vary only slightly due to the canopy porosity. Due to the increasing canopy porosity, the air velocity would increase, and the pollutant concentration would be reduced. The leaves are non-continuous and uniformly distributed at constant porosity, which does not significantly change the velocity distribution and pollutant concentration in the street canyon.


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