Download or read book Numerical Simulations of Indoor Airflow Conditions written by Anupreet Singh and published by . This book was released on 1999 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical and experimental investigations of distribution of gaseous emissions with the air flow in the indoor environment written by Umer Afzal and published by Logos Verlag Berlin GmbH. This book was released on 2017 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are many sources of emissions produced by burning fuel for power or heat, through chemical reactions, and from leaks from industrial processes or equipment. There is always a possibility of a potential hazard when these gases enter into the indoor environment with the air flow. The determination of the concentration profiles are necessary to evaluate the potential hazard posed by the gas spread. The main objectives of this work are to develop an appropriate measurement methodology and a 3D CFD transient multicomponent simulation model for the determination of spatial and temporal distribution of gaseous emissions with the air flow in the indoor environment. This work is also aimed at comparing the numerical simulation results of different CFD programs for a 2D base case model of indoor air flow with and without emission source under laminar and turbulent flow conditions for the purpose of developing a better basic understanding of the physical phenomena and for the selection of the suitable and appropriate CFD program for the further development of the simulation model. One of the goals is also to apply the developed simulation model to the loss prevention and risk mitigation in the indoor environment and to study the influence of different parameters on the concentration distribution of gaseous pollutants in the presence of air flow in the indoor environment to minimize the expensive and time consuming experimentation efforts.

Download or read book Numerical Simulation of 3 D Turbulent Room Airflow Pattern and Temperature Field in UC Solar Decathlon House written by Prachi Rojatkar and published by . This book was released on 2007 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study Computational Fluid Dynamics (CFD) has been used to simulate the airflow and temperature distribution patterns inside a Solar House (designed by University of Cincinnati team to compete in Solar Decathlon 2007) over a range of environmental conditions. Analysis of airflow and temperature field is presented for mechanically driven heating and cooling system (forced convection) and radiant floor heating system (natural convection). Main objective of the study is to analyze the design parameters for heating and cooling of the house with respect to indoor air distribution pattern and temperature field. Compliance with Solar Decathlon norms for indoor air temperature is also studied and corrective suggestions are made. Finally, thermal comfort for three major areas of the house (living/kitchen, bedroom and bathroom) is evaluated for each case. It can be concluded from the CFD study that the system design is satisfactory for the given house structure and will fulfill the requirements of thermal comfort.

Download or read book Air Distribution in Rooms written by H.B. Awbi and published by Elsevier. This book was released on 2000 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt: The air distribution in occupied spaces is a major issue of public concern. It is widely recognized that the quality of air and the nature of airflow can affect the health of occupants and the energy consumed in buildings and transport vehicles. ROOMVENT is the principal international conference in the field of air distribution. It was first initiated in 1987 by SCANVAC, the Scandinavian Federation of Heating, Ventilating and Sanitary Engineering Associations in Denmark, Finland, Iceland, Norway and Sweden. The aim of the Conference is to bring together researchers from universities and research institutes, engineers from industry and government officials and policy makers, with the goal of experiencing the latest techniques for measuring and analyzing indoor air flow, the visualization of indoor air flow patterns, the evaluation of ventilation parameters and the most recent developments in computer simulation techniques of room airflow. It is hoped that the theme of ROOMVENT 2000 "Ventilation for Health and Sustainable Environment" will set the scene for room air distribution research and development for the new millennium.

Download or read book Performance Study of Outlets and Its Impact on Airflow Characteristics written by Ramy Hamdy Abdelhady and published by LAP Lambert Academic Publishing. This book was released on 2014-10-15 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the investigation of indoor airflow in a sub-scale ventilated room is conducted using two approaches: experimental measurements and numerical simulations. The study concerns the prediction of comfort properties in a sub-scale room. Particular interest is concentrated on the three types of ceiling diffusers namely; square, round and swirl (vortex) diffusers. Basic parameters included air temperature, relative humidity, and air velocity are measured and/or predicated at different inlet conditions to obtain thermal comfort indices such as mean age of air, ventilation effectiveness, and effective draft temperature. Experiments are carried out to find the temperature profile for a certain space at conditions in the range of those expected in daily applications. These data are then used to verify and validate the numerical prediction. The experiments are performed by varying certain parameters and studying the effect of each of these parameters on the air temperature, the velocity profile and hence the thermal comfort.

Download or read book A Three Layered Framework for Annual Indoor Airflow CFD Simulation written by Yue Wang and published by . This book was released on 2013 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Modelling of Indoor Airflow written by Lijuan Zhang (M.E.Sc.) and published by . This book was released on 2007 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Numerical Simulation of In Flight Icing written by Wagdi George Habashi and published by Springer Nature. This book was released on 2024-01-12 with total page 1278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Handbook of Numerical Simulation of In-Flight Icing covers an array of methodologies and technologies on numerical simulation of in-flight icing and its applications. Comprised of contributions from internationally recognized experts from the Americas, Asia, and the EU, this authoritative, self-contained reference includes best practices and specification data spanning the gamut of simulation tools available internationally that can be used to speed up the certification of aircraft and make them safer to fly into known icing. The collection features nine sections concentrating on aircraft, rotorcraft, jet engines, UAVs; ice protection systems, including hot-air, electrothermal, and others; sensors and probes, CFD in the aid of testing, flight simulators, and certification process acceleration methods. Incorporating perspectives from academia, commercial, government R&D, the book is ideal for a range of engineers and scientists concerned with in-flight icing applications.

Download or read book Recent Advances in Urban Ventilation Assessment and Flow Modelling written by Riccardo Buccolieri and published by MDPI. This book was released on 2019-04-23 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains twenty-one original papers and one review paper published by internationally recognized experts in the Atmosphere Special Issue "Recent Advances in Urban Ventilation Assessment and Flow Modelling", years 2017–2019. The Special Issue includes contributions on recent experimental and modelling works, techniques, and developments mainly tailored to the assessment of urban ventilation on flow and pollutant dispersion in cities. The study of ventilation is of critical importance, as it addresses the capacity with which a built urban structure is capable of replacing the polluted air with ambient fresh air. Here, ventilation is recognized as a transport process that improves local microclimate and air quality and closely relates to the term “breathability”. The efficiency with which street canyon ventilation occurs depends on the complex interaction between the atmospheric boundary layer flow and the local urban morphology. The individual contributions to this Issue are summarized and categorized into four broad topics: (1) outdoor ventilation efficiency and application/development of ventilation indices, (2) relationship between indoor and outdoor ventilation, (3) effects of urban morphology and obstacles to ventilation, and (4) ventilation modelling in realistic urban districts. The results and approaches presented and proposed will be of great interest to experimentalists and modelers, and may constitute a starting point for the improvement of numerical simulations of flow and pollutant dispersion in the urban environment, for the development of simulation tools, and for the implementation of mitigation strategies.

Download or read book Proceedings of the ASME Fluids Engineering Division written by and published by . This book was released on 2002 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Turbulent Boundary Layers written by Tuncer Cebeci and published by Elsevier. This book was released on 2012-12-02 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculating two-dimensional and axisymmetric laminar and turbulent boundary layers. This book will be useful to readers who have advanced knowledge in fluid mechanics, especially to engineers who study the important problems of design.

Download or read book Modeling Indoor Air Pollution written by Darrell W. Pepper and published by World Scientific. This book was released on 2009 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design for prevention or remediation of indoor air pollution requires expertise in optimizing geometrical configurations; knowledge of HVAC systems, perceived or expected contaminants and source locations; and economics. This title describes a series of numerical models that run in MATLAB.

Download or read book Industrial Ventilation Design Guidebook written by Howard D. Goodfellow and published by Academic Press. This book was released on 2021-06-04 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: Industrial Ventilation Design Guidebook, Volume 2: Engineering Design and Applications brings together researchers, engineers (both design and plants), and scientists to develop a fundamental scientific understanding of ventilation to help engineers implement state-of-the-art ventilation and contaminant control technology. Now in two volumes, this reference contains extensive revisions and updates as well as a unique section on best practices for the following industrial sectors: Automotive; Cement; Biomass Gasifiers; Advanced Manufacturing; Industrial 4.0); Non-ferrous Smelters; Lime Kilns; Pulp and Paper; Semiconductor Industry; Steelmaking; Mining. - Brings together global researchers and engineers to solve complex ventilation and contaminant control problems using state-of-the-art design equations - Includes an expanded section on modeling and its practical applications based on recent advances in research - Features a new chapter on best practices for specific industrial sectors

Download or read book On the performance of stratified ventilation written by Ulf Larsson and published by Linköping University Electronic Press. This book was released on 2018-08-20 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: People nowadays spend most of their time indoors, for example in their homes, cars, in trains, at work, etc. In Sweden, the energy demand in the built environment is a growing issue. The building sector accounts for 40% of total energy use and 15% of total CO2 emissions, and around one-third of the energy use in the world is related to providing a healthy and good comfort indoors. To achieve acceptable indoor climates new designs for the ventilation systems have been proposed in recent decades, among them stratified ventilation systems. Stratified ventilation is a concept that often allows good performance for both indoor air quality and thermal comfort. Stratified ventilation systems are effective in reducing cross contamination, since there is virtually no mixing in the space; the temperature and the pollutant concentration increase linearly from the heat source with the height of the occupied zone. There are many different ventilation supply devices using the stratified principle, such as displacement supply device (DSD), impinging jet supply device (IJSD) and wall confluent jet supply device (WCJSD). The main aim of this thesis is to analyze and compare different supply devices based on stratified ventilation, with different setups, related to thermal indoor climate, energy efficiency and ventilation efficiency. The ultimate goal is to contribute to an increased understanding of how ventilation systems with stratified supply devices perform. Two scientific methods have mainly been used in this thesis, i.e., experimental and numerical investigations. For numerical experiments the CFD (Computational Fluid Dynamics) code ANSYS and FIDAP have been used. Experimental studies have been performed with thermocouples, Hot-Wire Anemometry (HWA) and Hot-Sphere Anemometry, thermal comfort measurement equipment and tracer gas measurement equipment. This thesis mainly focuses on three research questions: Interaction between a supply device based on stratified ventilation and downdraft from windows; Flow behavior, energy performance and air change effectiveness for different supply devices based on stratified ventilation; and Thermal comfort for different supply devices based on stratified ventilation. Research question one showed that the arrangement of displacement supply device and window in cold climate has significant effect on the flow pattern below the window. Different supply airflow rates have an effect on both the velocity and the temperature of the downdraft. In this case the velocity decreased by approximately 9.5% and the temperature in the downdraft decreased 0.5°C when the flowrate from the supply device increased from 10 to 15 l/s. Research question two showed that airflow patterns between different air supply systems were essentially related to characteristics of air supply devices, such as the type, configuration and position, as well as air supply velocities and momentum. For WCJSD, IJSD and DSD, positions of heat sources (such as occupant, computers, lights and external heat sources) played an important role in formation of the room airflow pattern. One interesting observation is that the temperature in the occupied zone is lower and a more stratified temperature field implies a more efficient heat removal by a stratified air supply device. The results revealed that the lowest temperature in the occupied zone was achieved for DSD, but with IJSD and WCJSD slightly warmer, while the system with a mixing supply device (MSD) showed a much higher temperature. The results confirm that air change effectiveness (ACE) for the DSD, WCJSD and IJSD is close to each other. However, MSD shows lower ACE in all the present papers than IJSD, WCJSD and DSD. Research question three showed that ventilation systems with stratified supply devices in almost all of the studied cases showed an acceptable level for predicted percentage dissatisfied (PPD), predicted mean vote (PMV) and percentage dissatisfied due to draft (DR). If comparing ventilation systems, using IJSD, WCJSD or DSD with MSD always showed thermal comfort better or at the same level. Människor spenderar en stor del av sin tid inomhus, exempelvis i sina bostäder och bilar, på tåg och på arbetet. Sveriges energibehov i den byggda miljön har en växande trend. Byggnadssektorn står för 40 % av det totala energibehovet och för 15 % av CO2 utsläppet och för cirka en tredjedel av energianvändningen i världen för att tillhandahålla en hälsosam och bra inomhusmiljö. För att skapa en bra inomhusmiljö har nya sätt att ventilera inomhusmiljön utvecklats under de senaste årtiondena. De olika principer som används för att ventilera en byggnad kan indelas i: kolvströmning, omblandande strömning och deplacerande strömning. De genererar rumsförhållanden som ger olika fördelning av hastighet, temperatur och föroreningar i det ventilerade utrymmet. Stratifierad ventilation är ett koncept som ofta ger ett bra utfall av både inomhusluftkvalitet och termisk komfort. Stratifierade system är effektiva för att minska korskontaminering, eftersom det nästan inte finns någon omblandning i rummet, temperaturen och föroreningskoncentration ökar linjärt från värmekällan med höjden i vistelsezonen. Det finns många olika ventilationsdon som använder den stratifierade principen, såsom deplacerande ventilationsdon (DSD), impinging jet-ventilationsdon (IJSD) och väggbaserad confluent jet-ventilationsdon (WCJSD). Huvudsyftet med denna avhandling är att analysera och jämföra olika tilluftsdon baserat på stratifierad princip i olika rumskonfigurationer med avseende på termiskt inomhusklimat, energieffektivitet och ventilationseffektivitet. Det yttersta målet är att bidra till ökad förståelse för hur ventilationssystem med olika stratifierade tilluftsdon fungerar. Två vetenskapliga metoder har huvudsakligen använts i denna avhandling: experimentella och numeriska analyser. För numeriska analyser har CFD (Computational Fluid Dynamics) använts. De simuleringsprogram som utnyttjats för detta ändamål är ANSYS och FIDAP. Experimenten har utförts med hjälp av termoelement, varmtråds- och varmsfärsteknik, mätutrustning för termisk komfort och mätutrustning för spårgas. Denna avhandling fokuserar framför allt på tre forskningsfrågor: interaktion mellan ett tilluftsflöde från ett deplacerande don och kallraset från ett fönster; strömningsbilden, energiprestandan och luftbyteseffektiviteten för olika tilluftsdon baserat på stratifierad ventilation; och termisk komfort för olika tilluftsdon baserade på stratifierad ventilation. Forskningsfråga ett visade att kombinationen av tilluftsflöde genom ett deplacerande don och fönster i kallt klimat har tydlig effekt på strömningsbilden för kallraset under fönstret. Olika tilluftsflöden har en effekt på både hastigheten och temperaturen i kallraset. I detta fall minskade hastigheten med ca 9,5% och temperaturen i kallraset minskade med 0,5°C när flödeshastigheten från tilluftsdonet ökade från 10 till 15 l/s. Forskningsfråga två visade att luftflödesmönstren mellan olika luftförsörjningssystem väsentligen var relaterade till egenskaper hos tilluftsdonen, såsom typ, konfiguration och position samt lufttillförselhastigheter och impulskraft. För WCJSD, IJSD och DSD spelade värmekällans placering, d.v.s. människor, datorer, belysning och externa värmekällor, en viktig roll vid utformningen av rummets luftflödesmönster. En intressant observation är att temperaturen i vistelsezonen är lägre och rummet har ett mer stratifierat temperaturfält, vilket innebär en effektivare ventilering av den zonen. Resultaten visade att den lägsta temperaturen i vistelsezonen uppnåddes för DSD medan IJSD och WCJSD visade en något högre temperatur, systemet med ett omblandande don (MSD) visade en påtagligt högre temperatur. Resultaten bekräftar också att luftförändringseffektiviteten (ACE) för DSD, WCJSD och IJSD ligger nära varandra. MSD visar dock i alla ingående artiklar lägre ACE än IJSD, WCJSD och DSD. Forskningsfråga tre visade att ventilationssystem med stratifierade tilluftsdon i nästan samtliga studerade fallen haren acceptabel nivå för predicted mean vote (PPD), predicted mean vote (PMV) och percentage dissatisfied due to draft (DR). Om man jämförde ventilationssystem IJSD, WCJSD eller DSD med MSD visade det sig alltid att den termiska komforten var bättre eller på samma nivå som för MSD.

Download or read book Numerical Simulations written by Lutz Angermann and published by BoD – Books on Demand. This book was released on 2010-12-30 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will interest researchers, scientists, engineers and graduate students in many disciplines, who make use of mathematical modeling and computer simulation. Although it represents only a small sample of the research activity on numerical simulations, the book will certainly serve as a valuable tool for researchers interested in getting involved in this multidisciplinary field. It will be useful to encourage further experimental and theoretical researches in the above mentioned areas of numerical simulation.

Download or read book Modeling of Indoor Air Quality and Exposure written by Niren Laxmichand Nagda and published by ASTM International. This book was released on 1993 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiphysics Simulation in Buildings written by Oussama Souaihi and published by . This book was released on 2018 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulation play an important role in the design, engineering, operation and management of buildings. It can help reducing energy consumption, improving indoor air quality and thermal comfort and provide quantitative data supporting decision making, e.g. choosing the best solution for designing, retrofitting or choosing the optimal HVAC system. Besides, buildings are composed more and more of different complex elements and systems which make the simulation of only thermal physics in buildings not enough to evaluate their whole performance. All the involved physical phenomena like moisture, airflow and pollutants should be considered and coupled in order to reproduce the reality with the highest possible level of details. In this context, this PhD thesis presents the models and the simulations of multi-physics inside buildings using an in-house developed modular and object oriented tool called NEST. All the physics of the coupled heat, moisture, airflow and pollutants transfer that take place inside buildings are considered and solved. In addition, the software allows the simulation of a building system as a collection of different numerical elements, like walls, rooms, HVAC systems, outdoor, etc., connected with each other and able to exchange boundary conditions. In this manner any building configuration can be set and simulated. The physical and mathematical formulations of the implemented elements are presented. Then, in order to assure the credibility of the developed software, the implemented models are validated and verified with different test cases from the literature. The list of test cases cover all the aspects of heat, moisture, airflow and pollutants transfer in the whole building and it can be used as a reference list for the validation of other buildings simulation tools. Special emphasis is placed on the simulation of buildings performance in real applications. First, the hygrothermal behaviour in different public buildings with different climates conditions are analysed before retrofitting them. Several weak points in the thermal and moisture resistance of the façades layers are identified and thermal and moisture loads before and after the expected retrofitting solutions are evaluated. Second, a residential building (semidetached house) in Netherlands is simulated and the airflow, heat and CO 2 transfer inside it is studied in order to optimize the energy consumption while maintaining acceptable levels of thermal comfort and indoor air quality.