Dissertations / Theses on the topic 'Indoor air and particle flow'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Indoor air and particle flow.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Tian, Zhaofeng, and rmit tian@gmail com. "Numerical Modelling of Turbulent Gas-Particle Flow and Its Applications." RMIT University. Aerospace, Mechanical and Manufacturing Engineering, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080528.150211.
Full textKanaani, Hussein. "Real time detectionof airborne fungal spores and investigations into their dynamics in indoor air." Queensland University of Technology, 2009. http://eprints.qut.edu.au/30350/.
Full textFunes-Gallanzi, Marcelo. "Unsteady flow measurements in air using particle image velocimetry." Thesis, University of Warwick, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307299.
Full textSaxena, Gaurav. "Air flow separation over wind generated waves." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 235 p, 2007. http://proquest.umi.com/pqdweb?did=1251900711&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full textHe, Congrong. "Airborne Particles in Indoor Residential Environment: Source Contribution, Characteristics, Concentration, and Time Variability." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16017/.
Full textBeausoleil-Morrison, Ian David. "The adaptive coupling of heat and air flow modelling within dynamic whole-building simulation." Thesis, University of Strathclyde, 2000. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21137.
Full textDoucet, Daniel Joseph. "Measurements of Air Flow Velocities in Microchannels Using Particle Image Velocimetry." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1333675768.
Full textSegal, Rebecca Anne. "Patterns of air flow and particle deposition in the diseased human lung." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010702-165013.
Full textSEGAL, REBECCA ANNE. Patterns of air flow and particle depositionin the diseased human lung. (Under the direction of Michael Shearer.)In this work, we investigate particle deposition and air flow in thehuman lung. In particular we are interested in how the motion ofparticulate matter and air is affected by the presence of lungdisease. Patients with compromised lung function are more sensitiveto air pollution; understanding the extent of that sensitivity canlead to more effective air quality standards. Also, understanding ofair flow andparticle trajectories could lead to the development of better aerosoldrugs to treat the lung diseases.We focus our efforts on twodiseases: chronic obstructive pulmonary disease (COPD) and bronchialtumors. Because COPD affects the majority of airways in a patientwith the disease, we are able to take a more global approach toanalyzing the effects of the disease. Using a FORTRAN codewhich computes total deposition in the lung over the course of onebreath, we modified the pre-existing code to account forthe difference between healthy subjects and patients with COPD. Usingthe model, itwas possible to isolate the different disease components of COPD andsimulate their effects separately. It was determined thatthe chronic bronchitis component of COPD was responsible for the increaseddeposition seen in COPD patients.While COPD affects the whole lung, tumors tend to belocalized to one or several airways. This led us to investigate theeffects of bronchial tumors in detail within these individualairways. Using a computational fluid dynamics package, FIDAP, wedefined a Weibel type branching network of airways.In particular, we modeled theairways of a four-year-old child.In the work with the tumors, we ran numerous simulations with variousinitial velocities and tumor locations. It was determined that tumorslocated on the carinal ridge had the dominant effect on the flow. Athigher initial velocities, areas of circulation developed downstreamfrom the tumors. Extensive simulations were run with a 2-D model. Theresults from the 2-D model were then compared with some initial 3-Dsimulations.In the development of the FIDAP model, we avoided thecomplications of flow past the larynx, by limiting the model togenerations 2-5 of the Weibel lung. We developed a realistic inletvelocity profile to be used as the input into the model. The skewednature ofthis inlet profile led to thequestion of boundary layer development and the determination of theentrance length needed to achieve fully developed parabolicflow. Simple scale analysis of the Navier-Stokes equations did notcapture the results we were seeing with the CFD simulations.We turned to a more quantitative, energy correctionanalysis to determine the theoretical entrance length.In conclusion, the presence of disease in the lunghas a large effect both on global deposition patterns and on localizedairflow patterns. This indicates the need for different protocolsregarding susceptibility of people to airborne pollutants that take intoaccount lung disease. It also suggests that treatment should accountfor changes in airflow in the diseased lung.
Henning, James C. "MEASUREMENT OF AIR FLOW VELOCITIES IN MICROSIZED IONIC WIND PUMPS USING PARTICLE IMAGE VELOCEMITRY." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1365424846.
Full textJohnson, Neil G. "Vision-Assisted Control of a Hovering Air Vehicle in an Indoor Setting." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2430.pdf.
Full textDelbosc, Nicolas. "Real-time simulation of indoor air flow using the lattice Boltzmann method on graphics processing unit." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/13546/.
Full textWan, Man Pun. "Indoor transport of human expiratory droplets in association with airborne infectious disease transmission using a multiphase-flow approach /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20WAN.
Full textLi, Huafeng, and s3024014@student rmit edu au. "Numerical and experimental studies of air and particle flow in the realistic human upper airway models." RMIT University. Aerospace, Mechanical & Manufacturing Engineering, 2010. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20100205.145548.
Full textCox, Jennie D. "Evaluation of Indoor Aerosol and Bioaerosol Methods and a HEPA Intervention." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1522312779209054.
Full textKumar, Anil. "Estimation and Mapping of Ship Air Wakes using RC Helicopters as a Sensing Platform." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/82910.
Full textPh. D.
Kucukal, Erdem. "EXPERIMENTAL AND CFD INVESTIGATIONS OF THE FLUID FLOW INSIDE A HYDROCYCLONE SEPARATOR WITHOUT AN AIR CORE." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1424174590.
Full textLjung, Sebastian. "CFD simulation of particle matter inside an automotive car and the purification efficiency of cabin air purifier." Thesis, KTH, Hållbara byggnader, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-257682.
Full textSyftet med den här avhandlingen var att studera luftflödesmönster och partikelfördelningen i en generell bilkabin för att utvärdera luftkvaliteten och se hur man kan förbättra den. En 3D CAD-modell skapades med hjälp av Solidworks och ett rutnät skapades med hjälp av ICEM CFD. ICEM CFD användes för att generera rutnätet och ANSYS FLUENT användes för simuleringarna. Totalt simulerades 12 olika fall bestående av olika inflödeshastigheter och ventilinställningar. De beräknade resultaten användes sedan för att analysera luftflödet och partikelfördelningen i hela bilkabinen. Med högre inloppsflöde var det fler partiklar som transporterades till bakre delen av bilkabinen. Överlag var partikelkoncentrationen högre i framdelen av kabinen när partiklarna introducerades i inloppsventilerna, särskilt vid låga inloppshastigheter. Att öppna recirkulationsventilerna resulterade i en liten minskning av luftflödet till bakdelen av kabinen och även så partikelfördelningen. När rökpartiklar introducerades i baksätena, stannade de för det mesta i bakdelen av kabinen, särskilt vid låga inloppsflödeshastigheter då luften inte blandades tillräckligt. Överlag innebar en högre inloppsflödeshastighet reducerade mängden av partiklar som fastnade på fram- och baksätena, men ökade mängden partiklar som fastnade på taket, golvet och på väggarna.
Bloom, Matthew. "Effects of Fan Cooling at Room Temperature on Indoor 20-km Cycling Time Trial Performance." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4482.
Full textYang, Xiaofan. "Multi-scale simulation of filtered flow and species transport with nano-structured material." Diss., Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4271.
Full textJohansson, Tom, and Viktor Ryberg. "Val av ventilationssystem för kontorsverksamhet : En kostnadsjämförelse." Thesis, KTH, Byggteknik och design, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149462.
Full textAccording to Folkhälsomyndigheten, 18 precent of the adult population claims they experience symptoms related to the indoor environment. These symptoms can consist of both common illnesses, such as fatigue and headache, to more serious diseases such as cancer (Folkhälsomyndigheten, 2013). The main task of a ventilation system is to satisfy the requirements regarding the indoor climate and thereby consequently prevent poor health. This report focuses on the complex problems regarding ventilation systems design and it´s economic consquences. The purpose with this report is to identify which airflow principle is the most cost effective for office operations basad on two distinct floor plans. Three airflow principles have been studied; consist of the CAV-, VAV- and DCV-principle. All principles were designed and dimensioned based on realistic conditions and the specific requirement regarding the indoor environment. Each ventilation system was designed differently depending on the applied airflow principle, which led to different economic pros and cons for each ventilation system. The airflow principle´s life cycle cost has been compared in an economic analysis. The economic analysises were based on comparisons between each ventilation system’s life cycle cost and it´s reigning conditions. The report deals with general problems and processes regarding the dimensioning and designing of the ventilation systems. The economic comparisons resulted in a substantial difference in investment- , operation- and the maintenance cost for each system. The results proved that the investment cost is the key factor when comparing the airflow principle´s life cycle cost.
Naegle, Nathaniel Stephen. "Force Optimization and Flow Field Characterization from a Flapping Wing Mechanism." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3278.
Full textStratigou, Evdokia. "Identification and characterisation of physicochemical processes controlling indoor concentrations of submicron aerosols and volatile organic compounds." Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2019. http://www.theses.fr/2019MTLD0007/document.
Full textThis thesis improves the scientific knowledge on the origin, behavior and fate of gas and particle-phase pollutants indoors under unoccupied unfurnished conditions. A first campaign provided a complete description of the physical processes controlling the indoor concentrations. Using well quantified parameters (air exchange rate, penetration factor and deposition rate), a mass balance model provided insights for the particle budget closure. The results showed that when indoor sources are not significant, a careful characterization of the abovementioned parameters allows to estimate PM2.5 and PM10 in a satisfying manner from outdoor data. However the PM1 fraction shows a significantly higher variability due to physicochemical transformations. Subsequently, a second intensive campaign was performed to investigate volatile organic compounds (VOC) and PM1 chemical composition in real time. A strong increase in VOC concentrations was observed when outdoor air penetrates indoors, especially oxygenated VOC which exhibited a significant dependence on relative humidity, while the changes observed for particles once indoors depend on their chemical composition and diameter, showing a decrease from 20% for submicron particles up to, 86% for large ones (>5. µm). The investigation of ammonium neutralization revealed an excess of ammonium indoors and outdoors, which is attributed to organic- in addition to inorganic-bonded ammonium nitrate. The latter showed a stronger dependency on temperature gradient from outdoors to indoors, revealing stronger thermal decomposition once indoors. In summary, the indoor environment acts mainly as a continuous emission source of VOCs, while the opposite trend is observed the particles due to possible transformations that can occur even under the simplest conditions, with no occupants and no furnishing
Blanchard, Olivier. "Exposition aux composés organiques semi-volatils reprotoxiques et neurotoxiques dans l'habitat." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S088/document.
Full textSemivolatile organic compounds (SVOCs) include a large number of chemicals compounds used as active substances or additives in building materials and in many consumer products. SVOCs are ubiquitous in indoor environments and frequently detected in settled dust and indoor air. This work has investigated indoor concentrations of 57 target compounds in 30 French dwellings and measurements were used to test an equilibrium model to predict their partitioning in indoor compartments. The results showed a strong ubiquity of SVOCs in French dwellings. The highest concentrations were measured for phthalates and to a lesser extent for bisphenol A, synthetic musks, some pesticides and PAHs. These results confirm the interest to assess human exposure to SVOCs in the French dwellings. The work on the predictive model showed that octanol/air partitioning coefficient (Koa) is a good predictor to estimate SVOC concentrations in a large number of buildings. However, some limits were identified and a better estimation of the parameters used in these models is required
Nasani, Ahmad Muntaser. "Etude des phénomènes électrofluidodynamiques sur les gaz empoussiérés en écoulement turbulent : application au transport pneumatique." Poitiers, 1987. http://www.theses.fr/1987POIT2307.
Full textHernández, Luis Miguel Teófanes Bendezu. "Desenvolvimento de um programa computacional para balanceamento de redes de distribuição de ar." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3150/tde-10112016-151410/.
Full textThe balancing of a net air distribution consists in establishment the correct flowrate in the terminals elements according the design. The bibliographic review show that the balancing applied in air distribution are consider at the 60`s. In the end of the 80\\2019s the mathematics models beginning applied to air flow simulation in ducts. In the present work the objective is studies the methodology to simulation and balancing air distribution nets using software. Different methods are studies to apply in balance: proportional method, T method and direct method. The direct method is adopted, which the flowrate is fixed and the pressure difference is obtained for the parallel paths. Using fluid-dynamics and electrical analogy concepts an algorithm was developed and a software was prepared. The applicatory developed was divided in 6 main stages: net characterization, continuous losses, local losses, total losses, flow simulation and path comparing. Using a case study the software was tested and the distribution net was simulating. This same net was balancing evaluated by a computational spreadsheet. The case study results present the values of pressure for the sections of the net, and the pressure differences to obtained the balancing. This values was consider coincident with the expected.
Silva, Cibele Alves da. "Análise do escoamento do ar em uma sala cirúrgica via simulação em CFD." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-06122016-083329/.
Full textDue the trend to construct sealed buildings for air conditioning purposes, noise control and aesthetics, problems regarding interior air quality (IAQ) of such environments have been occured. The main issues related to bad indoor air quality are inadequate ventilation (most part of the cases), followed by outdoor air contaminants, indoor air contaminants (internally generated) and, in a smaller scale, construction materials and microorganisms. In the specific case of a hospital building, air quality can have a direct and significant influence on the occurrence of nosocomial infections. The level of contamination is mainly influenced type air conditioning system. Hence the need for intensive control of contaminants in local air. Therefore, the air distribution systems play a fundamental task inside a surgical room for safety and thermal comfort of the patient and surgical team. The return air also plays a very important role in eliminating contaminated air generated within an operating room. This return takes place through so-called return grills. Due to the limitation of analytical studies and the high cost of experimental research, it is very relevant a numerical-computational investigation of the air flow of an operating room in order to analyze the air flow behavior and the air temperature. The focus of this study is to verify, via computer simulation based on CFD (Computational Fluid Dynamics), the effectiveness of the air distribution system used in surgical centers regarding the control of air, in order to achieve a proper quality of air. To validate the computer model, field measurements have been carried out and data have been collected for comparison with the simulation results. The case study to be considered for this project is the surgical room of the University Hospital of the University of São Paulo.
Sattari, Amir. "Investigations of Flow Patterns in Ventilated Rooms Using Particle Image Velocimetry : Applications in a Scaled Room with Rapidly Varying Inflow and over a Wall-Mounted Radiator." Doctoral thesis, KTH, Installations- och energisystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-167804.
Full textDet övergripande syftet med den första studien i avhandlingen var att undersöka hypotesen att ett pulserande inflöde till ett ventilerade utrymme har en potential till att förbättra ventilationens kvalitet genom att minska stagnationszoner och därigenom öka omblandningen. För genomförande av studien byggdes en experimentuppställning i form av en tvådimensionell (2D) småskalig modell av ett ventilerat rum. Strömningsmediet i modellen var vatten. Det tvådimensionella hastighetsfältet registrerades över hela modellen med hjälp av Particle Image Velocimetry (PIV). Vid ett stationärt tillflöde bildas ett stagnationsområde i centrum av rumsmodellen. Vid ett pulserade inflöde genererades sekundära virvlar. Med en egen utvecklad programvara var det möjligt att kvantifiera statistiken hos virvlarna. Det pulserade inflödet gjorde att inom området där det vid stationärt tillflöde fanns en stagnationszon ökade antalet virvlar i alla storlekar och fördelningen av virvlar blev mera homogen än tidigare. Detta kan förväntas ge upphov till förbättrad omblandning. Baserat på en grundläggande experimentell studie utförd i en småskalig tvådimensionell rumsmodell med vatten som strömningsmedium kan vi logiskt dra slutsatsen att ett pulserande tilluftsflöde har en potential att förbättra omblandningen. I en fortsatt studie i avhandlingen visuliserades och mättes hastighetsfältet och därefter beräknades statistiska värden av exempelvis medelhastighet, standardavvikelse och skjuvspänning hos hastighetsfluktuationerna i luftströmmen över en väggmonterad radiator med 2D-PIV-teknik. Bakgrunden till studien är att en bidragande orsak till partikelavsättning på väggytor är turbofores som uppträder vid en turbulent luftström. Studien genomfördes genom uppbyggnad av en fullskalig rumsmodell. Eftersom turbulens spelar en roll vid partikelavsättning genom turbofores är det viktigt att identifiera var det laminära flödet över radiatorn blir turbulent. Resultaten baserat på visualisering och PIV-mätningar indikerade att, för ett rum med denna typ av radiatoruppvärmning, blev flödet över radiatorn turbulent efter en dimensionslös längd lika med 5,0‒6,25 gånger radiatorns tjocklek. Ytors egenskaper är viktiga vid partikelavsättning. Därför har de geometriska egenskaperna hos några olika metoder för ytbehandling undersökts experimentellt med hjälp av en scanner för strukturerat 3D-ljus. Resultaten visar på skillnader i ytråhet hos de olika ytbehandlingsmetoderna. För att undersöka motståndet mot luftströmning längs ytan och den turbulens som genereras av ytorna registrerade vi gränsskiktsflödet över ytorna i en speciell luftströmningsrigg. Detta påvisade att motståndet hos de olika typerna av ytbehandlingsmetoder skilde sig mycket litet åt och därför är troligt vid deras påverkan på depositionshastigheten mycket liten.
QC 20150525
Joerger, Guillaume. "Multiscale modeling and event tracking wireless technologies to improve efficiency and safety of the surgical flow in an OR suite." Thesis, La Rochelle, 2017. http://www.theses.fr/2017LAROS009/document.
Full textImproving operating room management is a constant issue for modern large hospital systems who have to deal with the reality of day to day clinical activity. As opposed to other industrial sectors such as air civil aviation that have mastered the topic of industry organization and safety, progress in surgical flow management has been slower. The goal of the work presented here is to develop and implement technologies that leverage the principles of computational science to the application of OR suite problems. Most of the currently available models of surgical flow are used for planning purposes and are essentially stochastic processes due to uncertainties in the available data. We propose an agent-based model framework that can incorporate all the elements, from communication skills of the staff to the time it takes for the janitorial team to go clean an OR. We believe that human factor is at the center of the difficulty of OR suite management and should be incorporated in the model. In parallel, we use a numerical model of airflow at the OR suite level to monitor and simulate environment conditions inside the OR. We hypothesize that the following three key ingredients will provide the level of accuracy needed to improve OR management : 1) Real time updates of the model with ad hoc sensors of tasks/stages 2) Construction of a multi-scale model that links all key elements of the complex surgical infrastructure 3) Careful analysis of patient population factors, staff behavior, and environment conditions. We have developed a robust and non-obtrusive automatic event tracking system to make our model realistic to clinical conditions. Not only we track traffic through the door and the air quality inside the OR, we can also detect standard events in the surgical process. We propose a computational fluid dynamics model of a part of an OR suite to track dispersion of toxic surgical smoke and build in parallel a multidomain model of potential nosocomial contaminant particles flow in an OR suite. Combining the three models will raise the awareness of the OR suite by bringing to the surgical staff a cyber-physical system capable of prediction of rare events in the workflow and the safety conditions
Gai, Guodong. "Modeling of water sprays effects on premixed hydrogen-air explosion, turbulence and shock waves Modeling pressure loads during a premixed hydrogen combustion in the presence of water spray Numerical study on laminar flame velocity of hydrogen-air combustion under water spray effects Modeling of particle cloud dispersion in compressible gas flows with shock waves A new formulation of a spray dispersion model for particle/droplet-laden flows subjected to shock waves Particles-induced turbulence: a critical review of physical concepts, numerical modelings and experimental investigation A new methodology for modeling turbulence induced 1 by a particle-laden flow using a mechanistic model." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMIR14.
Full textThis PhD dissertation is dedicated to develop simple models to investigate the effect of water spray system on the premixed hydrogen-air combustion in the nuclear power plants. Specific simple models are developed to describe the water droplet evaporation in the flame, particle cloud dispersion after the shock wave passage, and turbulence length scale evolution with the presence of a water spray. A methodology is proposed to evaluate the spray evaporation effects on the propagation of the turbulent hydrogen flame inside a closed volume and a simple model is developed for the quantification of the laminar velocity deceleration with the droplets evaporation inside the flame. An analytical model is proposed for the prediction of particle cloud dispersion after the shock passage in the one-way formalism and another analytical model is dedicated to describe the spray-shock interaction mechanism and predict the appearance of a particle number density peak using the two-way formalism. A review of the important criteria and physical modelings related to the particle-induced turbulence modulation is given and a mechanistic model is used for the estimation of the turbulent integral length scales induced by the injection of particle clouds. These developed numerical models can be coupled to implement in the large-scale numerical simulations of the spray system effects on the accidental hydrogen explosions in the nuclear power plants
Hayati, Abolfazl. "Natural Ventilation and Air Infiltration in Large Single‑Zone Buildings : Measurements and Modelling with Reference to Historical Churches." Doctoral thesis, Högskolan i Gävle, Energisystem, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-24612.
Full textNaturlig ventilation är den dominerande ventilationsprocessen i äldre byggnader såsom kyrkor, och även i de flesta småhus i Sverige och övriga delar av världen. Luftinfiltration och vädring utgör viktiga komponenter i naturlig ventilation, där luftinfiltration är luftflöde genom oavsiktliga läckage i byggnadsskalet, medan vädring är avsiktligt luftutbyte genom stora öppningar såsom fönster och dörrar/portar. Vädring kan i sin tur ske ensidigt (genom en öppning) eller som tvärdrag (genom två eller flera öppningar belägna på olika ytterväggar). Det totala luftutbytet påverkar värmeförluster och inomhusluftens kvalité. I kyrkor orsakar avsättning av luftpartiklar en gradvis nedsmutsning av invändiga ytor, inklusive väggmålningar och andra konstföremål. Betydande mängder partiklar avges från besökare, tända ljus, rökelse, o.d. Tillfällig vädring kan minska detta problem, men även användas för att justera innetemperaturen. Föreliggande studie analyserar mekanismer och predikteringsmodeller gällande luftinfiltration och dörrvädring genom fältmätningar, vindtunnelförsök och datorsimuleringar. Luftinfiltration och vädring har samma drivkrafter, d.v.s. vind och termik (inne‑ute temperaturskillnader). Båda dessa drivkrafter är svåra att predicera, särskilt vindinducerade flöden och kombinationen av termik och vind. Två av de mest etablerade modellerna för luftinfiltrationsprediktering i byggnader har utvärderats via mätningar i tre kulturhistoriska stenkyrkor i Sverige. En korrigeringsfaktor av 0,8 föreslås för bättre prediktion av den ena modellen (som gav bäst resultat) gällande höga en-zonsbyggnader såsom kyrkor. En detaljerad numerisk modell är utvecklad för luftinfiltrationsprediktering, där indata baseras på fältundersökningar, inkl. IR-termografering och uppmätt av neutrala tryckplanet (NPL). Modellens funktionalitet har validerats via mätningar i en av fallstudierna och pekar på tämligen god prediktionsprestanda. Vidare utveckling av modellen föreslås, inkl. ett mer systematiskt kalibreringssystem, för olika typer av byggnader och väderförhållanden. Gällande vädring mättes både ensidigt flöde och tvärdrag genom portar i olika kyrkobyggnader med hjälp av spårgas samt direkta lufthastighetsmätningar i portöppning. Mätresultaten jämfördes med erhållna prediktioner från fyra tidigare utvecklade modeller för ensidig ventilation. De modeller som tog hänsyn till vindturbulens gav något bättre resultat. Enligt utförda mätningar medför en timmes ensidig portvädring i en kyrka cirka 50 % luftutbyte, vilket indikerar att detta är en tillämpbar ventilationsmetod, även för så pass stora byggnadsvolymer. Ett särskilt vädringsdiagram presenteras, som syftar till att underlätta uppskattning av erforderlig vädringsperiod. Vidare studerades predikteringsprestanda hos IDA Indoor Climate and Energy (IDA-ICE) simuleringsprogram avseende vädring, där simuleringsdata jämfördes med fältmätningar i en kyrka. Programmets prediktion av ensidigt luftflöde genom en öppen kyrkport var av samma storlekordning som det uppmäta; dock klarade programmet inte av att hantera inverkan av vindriktning så väl, vilket pekar på en utvecklingspotential. Avslutningsvis undersöktes vinddrivet flöde igenom portöppningar i en kyrkmodell i vindtunnel, där luftomsättningen mättes med hjälp av spårgasmetoden. Vid ensidig vädring observerades högre flöde vid högre vindturbulens och när öppningen var på vindsidan av byggnaden, i överensstämmelse med fältmätningarna. Dessutom var vädringsflödet vid tvärdrag i storleksordningen 15 högre än det vid ensidig vädring. Det verkar alltså som att man kan öka vädringstakten avsevärt om man kan åstadkomma tvärdrag. Kalibreringskonstanter presenteras också för en enkel ekvation för vinddrivet flöde genom portar. Vindtunnelstudien indikerar vidare att advektion genom turbulens är en viktigare vädringsmekanism än pumpning. Föreliggande arbete bidrar med kunskap speciellt kring luftinfiltration och vädring genom portar i höga en-zonsbyggnader. Resultaten kan även vara tillämpliga på andra typer av höga en-zonsbyggnader såsom industrihallar, atrier/ljusgårdar och idrottshallar.
Church project
Fu, Sijie. "Vélocimétrie par suivi 3D de particules pour la caractérisation des champs thermo-convectifs dans le bâtiment." Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4078/document.
Full textThe objective of this thesis is to conduct a comprehensive study on 3D Particle Tracking velocimetry (PTV) for thermal convective indoor airflow. This work mainly concentrates on the literature survey, the performance evaluation of 3D PTV measurement algorithms, and the experimental investigation for thermal convective indoor airflow using 3D PTV measurement technology. First, typical 3D PTV technology and its main previous applications for indoor airflow study are carefully reviewed. Then, the performances of different 3D PTV measurement algorithms are evaluated numerically and experimentally. Two sections consist of this part, one is to compare the measurement performances of typical PIV algorithm and 3D PTV algorithm, another is to compare the performances of seven complete 3D PTV algorithms. Last, based on the analysis in the thesis, the experimental investigation for indoor airflow generated by mixing ventilation method is conducted
Hassen, Barkai Allatchi. "Caractérisation d’un écoulement diphasique dans un airlift sous dépression. Application pour l’extraction des matières solides en suspension." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI038.
Full textBubble columns are gas-liquid contactors widely used in industry, especially in chemical, biological and mineralogical process applications. In the range of bubble columns available, the vacuum airlift is a French innovation with very interesting characteristics for hydraulic pumping, mass transfer and suspended matter separation. This thesis work is part of the development of this improved airlift, which is widely used in the industrial environment. The objective of the thesis is the hydrodynamic characterization of the airlift column under vacuum and analysis of its capacities to ensure the solid-liquid separation function. This work is exclusively experimental and the experimental setup is a vertical bubble column in plexiglass under vacuum and connected to a recirculation basin. The hydrodynamic analysis was carried out using a differential pressure sensor for the global study and using a double optical probe for local characterization. Results obtained made it possible to study flow regime. The main parameters obtained are the void fraction, superficial velocity and bubbles diameter. Particle Image Velocimetry is applied to visualize and analyze the flow structures in the recirculation basin. The extracting capacities of the column were studied in tap water with the addition of surfactants. Soluble casein and Methyl Iso Butyl Carbinol (MIBC) are the two surfactants that have given the best results in terms of solid-liquid separation of suspended matter. This work contributed to the understanding hydrodynamics for vacuum airlift column and helped to highlight the potential of this column in the solid-liquid separation process. This work also opens the way to numerical modelling of airlift column hydrodynamics from experimental results
Maurerová, Lenka. "Systémy TZB v nemovitých památkách." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-390239.
Full text(10709238), Yuanpei Zhao. "A Comparison of Air Flow Simulation Techniques in Architectural Design." Thesis, 2021.
Find full textThe fluid simulation in computer generates realistic animations of fluids by solving Navier-Stokes equation. The methods of simulation are divided into two types. The grid-based methods and particle-based methods. The former one is wildly used for scientific computation because of its precision of simulation while the latter one is used in visual effects, games and other areas requiring real-time simulation because of the less computation time it has.
The indoor airflow simulations with HVAC system in construction design is one specific application in scientific computation and uses grid-based simulation as the general-purpose simulation does. This study addresses the problem that this kind of airflow simulations in construction design using grid-based methods are very time consuming and always need designers to do pretreatment of the building model, which takes time, money, and effort. On the other hand, the particle-based methods would have less computation time with an acceptable accuracy in indoor airflow simulations because this kind of simulation does not require very high precision.
Then this study conducts a detailed and practical comparison of different fluid simulation algorithms in both grid-based methods and particle-based ones. This study's deliverable is a comparison between particle-based and grid-based methods in indoor airflow simulations with HVAC system.
The overall methodology used to arrive at the deliverables of this study will need two parts of work. The benchmark data is gathered from a CFD software simulation using FVM with a decent grid resolution. The particle-based data will be generated by simulation algorithms over the same set of room and furniture models implemented by OpenGL and CUDA. After the benchmark FVM simulation being conducted in a CFD software, the temperature field of airflow will be measured. After simulation, the temperature field are gained on each one of 4 particle-based simulation. A comparison standard is set and data will be analyzed to get the conclusion. The result shows that in a short simulation time period, after finding a proper number of particles, the particle-based method will achieve acceptable accuracy of temperature and velocity field while using much less time.
Sarwar, Md Golam. "Fine particle formation in indoor environments levels, influencing factors and implications /." Thesis, 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3126114.
Full textYi, Shen Huan, and 沈桓毅. "Factors affecting the particulate concentration of different particle sizes in office's indoor air." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/06590787136591898030.
Full text中國醫藥大學
環境醫學研究所
93
The objective of this study is to investigate the concentrations of particulate in different particle sizes (PM2.5、PM10 、PM25) and assess the affecting factors. Particle measurement in a office of high-building was assessed by direct-reading instrument (PC-2 Quartz Crystal Microbalance, QCM) during three study periods, which is consecutively provide the particle size and concentration each one time per ten minutes. Information of office including open type, hood system, number of person, room temperature and humility, sand storm were recorded during study period. Results indicated the particle size of PM2. 5 dominated in indoor air. Using multiple linear regression and autogression models, significant factors of particle concentrations in three types of particle size had room temperature and humidity, hood opened and the presence of sand storm. The high peak of particle concentration was apparent during the sand storm because of the ventilation system in this high building can move across from outdoor air. Using the ion-production instrument was evaluated and calculated the remove efficiencies with approximately 30% for particle sizes, and with 15.782% and 22.22% for nicotine and 3-ethylpyridine , respectively. We conclude that particle concentrations in different particle sizes show a significant association between indoor air and outdoor air, especially during the presence of sand storm. Both types of the particle and/or gaseous was efficiently dropped away indoor air using ion-production instrument. Keywords: particle size 、nicotine、sand storm、direct-reading instrument
Boor, Brandon Emil. "Monolayer and multilayer particle resuspension from indoor surfaces : literature review and experimental methodology." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-12-2609.
Full texttext
Liu, Shichao active 21st century. "The effects of indoor jets on air distribution and human exposure to particles." Thesis, 2014. http://hdl.handle.net/2152/28349.
Full texttext
(10586768), Bhavini Singh. "Spark induced flow in quiescent air." Thesis, 2021.
Find full textNanosecond spark plasma actuators provide an opportunity to reduce pollutants by promoting efficient combustion in engines or provide targeted, tunable, flow control over vehicles, due to their ability to influence flow and combustion through multiple mechanisms. The plasma actuators can be physically unobtrusive, can be turned on and off and their low duty cycle, large bandwidth, and light weight make them more appealing than other control approaches. One method by which these plasma actuators interact with the environment is by inducing a complex local flow field and in order, to design scalable, high frequency actuators effectively, it is necessary to first understand the flow induced by a single spark discharge. Most experimental analysis on the flow induced by spark discharges has been restricted to qualitative descriptions of the flow field, primarily due to the difficulties associated with measuring such a transient and highly complex flow with sufficient spatiotemporal resolution. Quantitative, experimental characterization of the flow induced by a spark discharge remains lacking.
A spark discharge produces a shock wave and a hot gas kernel with a complex flow field following the shock. In this work, combined experimental and theoretical characterization of the spark induced flow is performed through a series of high spatiotemporal resolution measurements of the density and velocity fields and reduced-order modeling. The work investigates the mechanisms driving the cooling and vorticity generation in spark induced flow and the 3D nature of the flow field. Planar (2D-3C) and volumetric (3D-3C) velocity measurements are taken using stereoscopic particle image velocimetry (SPIV) and tomographic PIV, respectively. Density measurements are taken using background oriented schlieren (BOS) and high speed schlieren imaging is used to capture the shock wave induced by the spark.
The work shows that spark plasma discharges induce vortex rings whose vorticity is likely generated due to baroclinic torque arising from the non-uniform strength of the induced shock wave. The hot gas kernel cools in two stages: an initially fast cooling regime, followed by a slower cooling process. Reduced order analytical models are developed to describe the cooling observed in the fast regime and the role of the vortex rings in the entrainment of cold ambient gas and the cooling of the hot gas kernel. The results show that the vortex rings entrain ambient gas and drive cooling in the fast, convective regime, cooling approximately 50% of the hot gas within the first millisecond of the induced flow. An increase in the electrical energy deposited in the spark gap increases the shock strength and curvature and increases the vortex ring strength, thereby increasing the cooling rate and expansion of the hot gas kernel. The volumetric velocity measurements capture one of the two induced vortex rings and provide a framework for the improvements needed in future tomographic PIV experiments of the spark induced flow field, necessary in assessing the 3D nature of the induced vortex rings.
The results of this work provide the first set of
quantitative, experimental data on flow induced by nanosecond spark discharges
that can be used for validation of computational fluid dynamics (CFD) simulations.
The results demonstrate that spark plasmas induce vortex ring-driven mixing
flows and the results on mixing and cooling of the hot gas kernel can be
extended to any passive scalars present in the flow field as well as inform
pulsation frequencies and actuator designs for flow and combustion control. The
results from the reduced order modeling can inform future studies and
applications of nanosecond spark discharges and can be extended to a variety of
other types of plasma discharges like laser sparks, long duration sparks and
surface discharges with similar induced flow fields.
GUO-YANG, WENG, and 翁國揚. "The Effects of Opening Design on Indoor Air Flow─Implementation in Elementary School Classroom." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/31376797293599649813.
Full text國立臺灣科技大學
建築系
89
Although it has been found that the influence of the inlet position on airflow patterns form was greater than the outlet position, most of previously studies were a made in qualitative manners. Quantitative information is required for design implementation. The current study investigated the main factors that affect indoor airflow by using computer simulation. The classroom in elementary school was used as the simulation subject. First, The experiment was aimed at determining a feasible parameter setup. Second, The research was choose variables and divide into groups. The variables for controlling airflow indoors included opening area, opening pattern, position, window type, shading devices (position, depth and attachment), the student’s desks and human body etc. The study was probed into the airflow indoors which the external wind velocity is very low. The simulation wind velocity set 0.5 m/s. When the controlled inlet area of was smaller than the outlet area (fixed at 4.32m2), overall airflow is the faster. However, this caused air-draft unless only the vent was opened where a large region of eddy current was. If the opening was raised by 20 cm the effect was smaller. As for the effects of window type, vertical sliding window average yielded the strongest airflow while the vertical casement window yielded the weakest one. Besides, horizontal window shutter could significantly reduced flow speed. Attached shading devices could reduce average flow-speed by 15%. When the shading devices were detached as far as 60 cm, the average flow-speed indoors might restore and approach the original data with attached shading devices. Adding desks and human bodies not only resolved the drafting problems by reducing the flow-speed near the inlet (by 63%) but also improve the distribution. The study provided further understanding for the opening of building and the airflow in classroom of elementary school. In the future full-scale experiments can be used to verify the results of the current study.
Yang, Chung-Chin, and 楊仲謹. "The Developments of Air Quality Wireless Sensor Network for Particle and Indoor PM10 & PM2.5 Prediction Model." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/b5c8qp.
Full text國立臺北科技大學
環境工程與管理研究所
101
This study developed a system for Air Quality Wireless Sensoring Network (AQWSN), which could be monitor the PM2.5 and PM10 concentration from indoor and outdoor. By monitored the real sites for PM2.5 and PM10 concentration, this study develop an Indoor Air Quality Model (IAQM) to predict indoor PM2.5 and PM10 concentration. And to validate the precision for IAQM, this study used Mean absolute percentage error (MAPE) and American society for testing and materials (ASTM).The results showed that used hourly predict method and discrete parameter have a excellent predict value for indoor PM2.5 and PM10 concentration .The method has well efficiency for monitored indoor particle immediately. On the other side, the methed used hourly predict method and continuous parameter and hour average ventilation rate have a excellent predict value for PM2.5 and PM10 concentration in real space. After the AERMOD simulated the reduction scenario of PM2.5 and PM10 concentration, the annual average of PM2.5 and PM10 concentration reduced to 54.8% and 54.17% respectively.The total exposure reduction of PM2.5 and PM10 is 3.91μg/m3 and 6.61μg/m3 respectively, which can save 23.87 and 41.03 dollars/person-year respectively and extend 0.78 and 0.47 day/person-lifetime respectively.
Yeh, Cheng Hsin, and 葉承欣. "Removal of CO2 from indoor air by alkanolamine in a cross-flow rotating packed bed." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/35689312110923909955.
Full text長庚大學
化工與材料工程學系
100
The content of CO2 in atmosphere is getting higher level year by year. Recently, a lot of literatures concerning about the removal of CO2 from a gas stream containing huge flow rate and high CO2 concentration can be found. However, there are no existing literatures until now to examine how CO2 is removed from ambient air with huge flow rate using a cross-flow rotating packed bed. In this study, CO2 in ambient air was removed by monoethanolamine (MEA) and piperazine (PZ) using a cross-flow rotating packed bed with the effects of liquid flow rate, gas flow rate, and rotor speed. The results of this study demonstrate that the removal efficiency of CO2 increased with liquid flow rate and rotor speed. However, the removal efficiency of CO2 decreased with gas flow rate. The removal efficiency of CO2 was 91.5% with 1.0M MEA/1.0M PZ, at a gas flow rate of 70 L/min, a liquid flow rate of 0.5 L/min, and a rotor speed of 1800 rpm. CO2 in a 38.6 m3 room was removed using the same cross-flow rotating packed bed. CO2 can be removed completely with a gas flow of 70 L/min, a liquid flow of 0.5 L/min, and a rotor speed of 1800 rpm, as measured after 50 min.
Wu, Shiau-Feng, and 吳効峰. "Effects of air-sparging on particle deposition and filtration flux in cross-flow microfiltration." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/83200748696282334187.
Full text淡江大學
化學工程與材料工程學系碩士班
96
The effects of filtration flux、adhesion probability、cake properties and shear stress by changing liquid velocities、gas velocities and filtration pressures for air-sparging cross-flow microfiltration are studied. A filter membrane made of mixed cellulose ester with a mean pore size of 0.1 μm is used for filtering wide size distribution range particles, PMMA-7G. The flow behavior will change when gas velocity increases. Shear stress can restrain cake mass availability and improve filtration rates under bubble flow, but specific filtration resistance will increase clearly and filtration rates worse than no sparging filtration under slug flow。Because of shear stress increase rapidly。A great of particle decrease above 5μm. Smaller particle move in the void and the porosity become reduce. On the other hand, the cake layer compressed when fluid went past, so the specific filtration resistance increases glaringly. Communion with force analysis, we can find air-sparging force plays important role in filtration process, and we can use simulation analysis to forecast the tendency for particle distribution and adhesion property.
Boor, Brandon Emil. "Studies on particle resuspension, infant exposure, and the sleep microenvironment." Thesis, 2015. http://hdl.handle.net/2152/31356.
Full textFernandes, John Edward. "Visualizing the flow induced by an air curtain over a mannequin using stereo particle image velocimetry." 2008. http://hdl.handle.net/10106/1719.
Full textRim, Donghyun. "Evaluation of human exposure to indoor airborne pollutants : transport and fate of particulate and gaseous pollutants." 2009. http://hdl.handle.net/2152/18395.
Full texttext
Huang, Ming-I., and 黃明夷. "Investigation on the Application of the Particle Removal Mechanism of Ultra-Sonic Air Flow to Clean Glass Surface." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/85892975985789794681.
Full text逢甲大學
材料與製造工程所
94
In the thin film transistor liquid-crystal display industry domain, to remove the dust particle form glass plate surface, there are mainly dry and wet types of cleaning technologies. The paper takes dry cleaner to be the cleaning technology as the research foundation because it has been studied among the development various types cleaning technology and as succeeded technology of the plant use, removes the glass foundation plate surface dust particle. Foundation of this research is under this high-velocity current auxiliary by the ultra-sonic wave technology discussion glass foundation plate on the particle removing mechanism and the potency. In this article, first, we will make the literature review of the surface cleaning technology at present. The theories of ultra-sonic wave, basic hydromechanics, and the cause analysis of particle attaching the glass foundation plate, will also be mentioned. By means of establishment of the ultra-sonic wave air current particle removing pattern, we obtained parameters of the different particle removing rate and applied them to D.O.E(Design of Experiment)and static software MINITAB. With the investigation of the interactive impact of factors, we found that the optimistic parameter to control the mechanism of particle remove by ultra-sonic wave.
Hsu, Shou-Ping, and 許守平. "The programming and evaluation of clean effect of air particle''s concentration and air change rate at clean room with non-laminar flow in pharmaceutical factory." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/08313221807342918328.
Full text國立雲林科技大學
工程科技研究所博士班
95
This essay is to analyze the clean room in pharmaceutical factory.For example, the 100k clean room makes the concentration of air particle that affects the mathematic mode of the air change rate, and builds up a curve of the relation between the concentration of air particle and of air change rate. Therefore base on local concentration of outdoor and indoor air particle concentration, the designer can easily check the air change rate that the air conditioning system needs. However, in practical use, it can not below the circulating level calculated by room sensible heat. As the result of locale test, at any time, the max of air particle concentration in each room doesn''t beyond the designed upper limit. When it is at static state or slightly working, the indoor air particle concentration is too low, then could design a system that can change the air quantity(variable air volume,VAV), in order to save the energy consumption when ventilator is operating.
Stenberg, Berndt. "Office illness : the worker, the work and the workplace." Doctoral thesis, 1994. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100701.
Full textDiss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 5 uppsatser.
digitalisering@umu
Schmeling, Daniel. "Experimental Acquisition and Characterisation of Large-Scale Flow Structures in Turbulent Mixed Convection." Thesis, 2014. http://hdl.handle.net/11858/00-1735-0000-0022-5F32-8.
Full text