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1
Odewole, Gboyega Akindeji. "Airflow patterns in ventilated wall cavities." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/airflow-patterns-in-ventilated-wall-cavities(f67d5b52-af96-4784-a1ac-6d6c3c41812e).html.
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Though heating, insulation, wall claddings and cavity-wall construction are considered as measures for remediating moisture and condensation in buildings, ventilation of wall cavities has however become a mantra among architects and other building professionals. Holes of any size and shape are made and located on building facades based on the accepted wisdom that a little air movement will keep the wall cavities dry. Whilst ventilation has been found to be successful in the control of moisture and condensation in rooms and larger enclosures, there is however insufficient understanding of how it works in thin spaces with high aspect ratios, such as the wall cavities studied in this thesis.In order to put in place good control and management practices in the remediation of moisture and condensation in vertical wall cavities by natural ventilation, it is vital to understand the dynamics of airflow in these cavities. In this thesis therefore, different size and shape of slots were employed to numerically investigate the effects of size, spacing and number of the slots on the characteristics of the velocity fields (patterns of airflow and distributions of velocity) in different cavity models. The Reynolds-Averaged-Navier-Stokes (RANS) methodology was employed to simulate the cavity flows under different modelling conditions using FLUENT. The BS 5925 model, an empirical relation for predicting ventilation rates in rooms and other larger enclosures, was employed and modified to predict ventilation rates in these cavities. Experimentally, the mapping of the airstreams in these cavities was obtained under similar reference (inlet) wind speeds employed for the numerical investigations.The results of this study show that there exists a potential at higher wind speeds for natural ventilation in the remediation of moisture and condensation in the cavities of vertical walls. The steady state approach employed in the RANS-based computation of cavity flows in this thesis averages out the peak values of air velocities and therefore gives no information about regions of maxima or minima velocity values even at higher wind speeds. This makes the predicted air change rates insensitive to the inlet air velocities from the ventilation slots and therefore makes the results more applicable for long term control and management of moisture in these cavities. In order to therefore put in place short, medium and long term plans for remediation of moisture in these wall cavities, a time-dependent computation is required. This will also allow the efficiency of the cavity ventilation to be properly assessed. Using the modified BS 5925 model, reasonable predictions were obtained for the air change rates of the wall cavities with the different size of ventilation slots employed. Close agreements are also obtained at lower and higher wind speeds between the predicted ventilation rates from the modified BS 5925 model and the experimental results employed as benchmark for validating the results.
2
Moloney, Kenneth W. "An analysis of airflow patterns in auxiliary ventilated drivages." Thesis, University of Nottingham, 1997. http://eprints.nottingham.ac.uk/12364/.
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In recent years the drivage advance rates achieved within the UK coal industry have increased. In the 1980's average drivage rates were 35m per week compared to the 100/150m per week possible today. These extended rates of advance have resulted in an increase in the potential methane, dust and heat generation within the vicinity of the drivage face. In order to effectively disperse this additional pollutant load a controlled increase in air quantity is required. Although advance rates have changed, current auxiliary ventilation practice has not. UK mining law requires that the fresh air must be delivered to within 5m of the face. This has lead to the wide spread adoption of the use of overlap auxiliary systems within mechanised drivages, since a pure forcing system set at this distance from the face would lead to excessive airborne dust. UK mining law does not at present consider on-board mounted exhaust scrubber fans to constitute an effective overlap fan within mechanised drivages. Consequently an additional overlap exhaust fan is required to be installed within such drivages. In an attempt to determine whether working conditions could be safely and economically improved within mechanised rapid development drivages utilising an on-board mounted exhaust fan, a series of preliminary full scale gallery trials were conducted. A summary of the principal findings of these trials is presented together with an outline of a series of representative CFD simulations. This thesis examines the accuracy of CFD simulations for auxiliary ventilated headings. This is achieved by utilising Laser Doppler Anenometry (LDA) in a scale model representative of an underground heading and a detailed underground measurement programme conducted in production headings. These measured airflow values are then compared with representative CFD simulations and conclusions
3
Landolt, Scott David. "An analysis of airflow patterns inside precipitation gauge shielding." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1453573.
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Watkin, Sara Louise. "Cerebral haemodynamic effects of pauses in nasal airflow defined using near infrared spectroscopy." Thesis, Keele University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319025.
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Mayes, Julian C. "Regional airflow patterns in the British Isles and their influence on rainfall fluctuations." Thesis, Swansea University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260186.
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Cain, Melissa 1982. "Analysis of buoyancy driven airflow patterns in a model of a naturally ventilated building." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32797.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (leaf 22).
Models can help us understand the climate conditions inside naturally ventilated buildings in order to improve the efficiency of the design. Naturally ventilated buildings use temperature gradients to create buoyancy forces in the space and drive the airflow pathways in the space. One architectural design feature that facilitates natural ventilation is the presence of stack ventilation in the roof of the building, which facilitates the expulsion of heated air from the space. An architectural feature that changes the airflow pathways is the presence of railing on the upper floors where there is a danger of falling into the atrium. Using the model of a naturally ventilated building located in the Building Technology Department at MIT airflow visualization studies were carried out using incense to view the airflow patterns in the model. The variables of temperature, size of stack ventilation opening, and whether there were railings in the building or not were varied to determine their effects on the airflow. Temperature had the effect of increasing the velocity of the airflow, but did not significantly change the overall airflow profile. The size of the stack vent opening changed the airflow pathways significantly as did adding railings into the model. Comparing the results with a computational fluid dynamics model shows that there are some discrepancies.
by Melissa Cain.
S.B.
7
Detaranto, Michael Francis. "CFD analysis of airflow patterns and heat transfer in small, medium, and large structures." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/50813.
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Designing buildings to use energy more efficiently can lead to lower energy costs, while
maintaining comfort for occupants. Computational fluid dynamics (CFD) can be utilized to
visualize and simulate expected flows in buildings and structures. CFD gives architects and
designers the ability to calculate the velocity, pressure, and heat transfer within a building.
Previous research has not modeled natural ventilation situations that challenge common design
rules of thumb used for cross-ventilation and single-sided ventilation. The current study uses a
commercial code (FLUENT) to simulate cross-ventilation in simple structures and analyzes the
flow patterns and heat transfer in the rooms. In the Casa Giuliana apartment and the Affleck house,
this study simulates passive cooling in spaces well-designed for natural ventilation. Heat loads,
human models, and electronics are included in the apartment to expand on prior research into
natural ventilation in a full-scale building. Two different cases were simulated. The first had a
volume flow rate similar to the ambient conditions, while the second had a much lower flow rate
that had an ACH of 5, near the minimum recommended value Passive cooling in the Affleck house
is simulated and has an unorthodox ventilation method; a window in the floor that opens to an
exterior basement is opened along with windows and doors of the main floor to create a pressure
difference. In the Affleck house, two different combinations of window and door openings are
simulated to model different scenarios. Temperature contours, flow patterns, and the air changes
per hour (ACH) are explored to analyze the ventilation of these structures.Master of Science
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Kantipudi, Rohini. "Computational Fluid Dynamics Modeling Of Airflow patterns around a Room-and-pillar mining face area." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1968005101&sid=21&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Md, Azmi Ahmad Zharif. "CFD ANALYSIS OF AIRFLOW PATTERNS IN HIGH MINING AREAS OF ROOM-AND-PILLAR COAL MINING." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/theses/1574.
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This thesis studies airflow patterns in the face area of a typical room-and-pillar mining area, using Computational Fluid Dynamics (CFD) modeling. This research is designed to develop a scientific understanding of airflow distribution in room-and-pillar mining areas that is fundamental to developing engineering controls. The overall goal of the study is to develop improved engineering controls to minimize dust exposure of mine workers in the face area. Dust exposure can be a health hazard in underground coal mining industry based on historical data of coal workers' pneumoconiosis among underground mine workers. Current regulatory dust exposure standards of 1.5 mg/m3, averaged over an 8-hour period, have been recently revised with approval of new MSHA standards in April of 2014. Mining companies are currently seeking new technologies in order to comply with the new dust standards. Since mining geometries are complex and do not lend themselves to closed-form analytical solutions, CFD numerical modeling approach was used to develop an understanding of airflow distribution in the face areas. Since previous studies had focused on some cuts in mining heights of less than 2.4 m (8-ft), this study was performed for high mining areas of 4.2 m (14-ft). Such mining heights are very common in longwall mine development areas, particularly in the State of Illinois. The primary goal was to identify major differences in airflow between the two mining heights and how they affect development of engineering controls for minimizing dust exposure. Simulations were done using ANSYS software such as DesignModeler for modeling and meshing and FLUENT for calculations. Recirculation (RC) and low air velocity (LAV) zones were located for straight deep cut, straight deepest cut, cross-cut right, cross-cut right mine through, left turn cross-cut, and left turn cross-cut mine through for low mining height (LMH) and high mining height (HMH) with varying air quantity at the end of the line curtain (ELC). Air at the ELC was adjusted to achieve a ratio of 0.85, 1.00 and 1.15 over the wet scrubber fan (WSF) discharge capacity. Results show that the air velocity in HMH case is much lower than for the LMH. In addition, the location of RC and LAV zones differ based on mining height and air quantity at the ELC. Furthermore, lower air quantity at the ELC causes the air exhausted by the WSF to recirculate back to the face area in order to satisfy the WSF requirement. Recommendations to deal with these differences are formulated.
10
Madden, Michael Levi. "The effects of passenger loading and ventilation air on airflow patterns within an aircraft cabin." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/19107.
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Master of ScienceDepartment of Mechanical and Nuclear Engineering
Mohammad H. Hosni
Byron W. Jones
With the increasing number of passengers traveling on commercial aircraft, it is important to mitigate the possibility of diseases and contaminants spreading throughout aircraft cabins and becoming harmful to the health of passengers. The ventilation system on a Boeing 767 aircraft is designed to create lateral flow to isolate contaminants to a single row of the cabin and remove the harmful air quickly. There are many variables that can influence the airflow patterns inside the cabin. The thermal plumes created by occupants are one of the variables investigated in this experimentation. Another special case investigated is the transport of gases in the cabin when the ventilation air is eliminated. Experimentation is performed in a mock-up Boeing 767 cabin. The mock-up enclosure consists of 11 rows and 7 columns of seats in each row. Ventilation apparatus, seating, and cabin dimensions used for testing are all representative of an actual aircraft. Thermal manikins are placed in the cabin seats to simulate the heat load from a seated person. A mixture of carbon dioxide (CO²) and helium (He) is injected into the cabin as a tracer gas to simulate the release of contaminants. The CO² concentration is measured by analyzers placed at the cabin inlet, exhaust, and seat of interest. The tracer gas can be injected and sampled at any of the 77 seats. In order to determine the effects of passenger density, testing is performed with maximum occupant load and repeated with half of the passenger load. Tracer gas is injected in three locations of the cabin and sampled in 32 seats for each injection seat. The testing revealed a significant effect of passenger load on airflow patterns. To determine the effects of removing the ventilation air, the cabin is supplied with 1400 cfm of outdoor air at 60°F for three hours to bring the cabin to a steady state temperature. Then, the supply air is shut off, and tracer gas is injected into the cabin and the CO² concentration is sampled at 12 locations throughout the cabin. It was found that contaminants are still transported throughout the cabin without the ventilation air.
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Shupe, Andrew C. "Convective Flow Patterns of a Three Generation Bifurcation Model." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1353035707.
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Anderson, Michael D. "Effect of gaspers on airflow patterns and the transmission of airborne contaminants within an aircraft cabin environment." Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/14988.
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Master of ScienceDepartment of Mechanical and Nuclear Engineering
Mohammad H. Hosni
Byron W. Jones
Due to the high occupant density and large number of travelers on commercial aircraft, it is crucial to limit the transport of contaminants and pathogens amongst passengers. In order to minimize the exposure of passengers to various contaminants of different sizes and characteristic, all mechanisms influencing airflow movement within an aircraft cabin need to be understood. The use of personal gaspers on commercial aircraft and their relation to airborne contaminants and pathogens transport is one such mechanism that was investigated. Tracer gas testing using carbon dioxide (CO[subscript]2) was conducted in a wide-body, 11-row Boeing 767 aircraft cabin mockup using actual aircraft components for air distribution. Three separate experiments were conducted investigating the effect of gaspers on the transport of contaminants. The first series of experiments focused on the effect of gaspers on longitudinal transport patterns within an aircraft cabin environment by measuring the concentration of tracer gas along the length of the aircraft cabin. The second experiment investigated what fraction of air a passenger inhales originates from a gasper in relation to the overall cabin ventilation. The final set of experiments determined if gaspers could limit close range person-to-person transmission of exhaled contaminants. Three separate sets of conclusions were drawn, one for each series of experiments. The first conclusion is that gaspers disrupt the longitudinal transport of contaminants within the aircraft cabin. The second conclusion is that less than 5% of the air inhaled by a passenger is originating from a gasper even with a gasper directed at the passenger's face. This low percentage is a result of the turbulent airflow within the aircraft cabin causing the gasper jet to quickly mix with the overall cabin ventilation air. The last conclusion is that gaspers can reduce person-to-person transmission of exhaled contaminants as much as nearly 90% in some cases. In other cases the gaspers are found to have negligible or negative impact on the transmission of contaminants. These conclusions are dependent upon where the tracer gas plume emanated from, the sampling location, and the configuration of gaspers around the tracer gas release point.
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Inthavong, Kiao, and kiao inthavong@rmit edu au. "Simulation of Fluid Dynamics and Particle Transport in a Realistic Human Nasal Cavity." RMIT University. Aerospace, Mechanical and Manufacturing Engineering, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081202.162555.
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Airflow and particle transport through the nasal cavity was studied using Computational Fluid Dynamics (CFD). A computational model of the human nasal cavity was reconstructed through CT scans. The process involved defining the airway outline through points in space that had to be fitted with a closed surface. The airflow was first simulated and detailed airflow structures such as local vortices, wall shear stresses, pressure drop and flow distribution were obtained. In terms of heat transfer the differences in the width of the airway especially in the frontal regions was found to be critical as the temperature difference was greatest and therefore heating of the air is expedited when the air is surrounded by the hotter walls. Understanding the effects of the airway geometry on the airflow patterns allows better predictions of particle transport through the airway. Inhalation of foreign particles is filtered by the nasal cilia to some degree as a defence mechanism of the airway. Particles such as asbestos fibres, pollen and diesel fumes can be considered as toxic and lead to health problems. These particles were introduced and the effects of particle morphology were considered by customising the particle trajectory equation. This mainly included the effects of the drag correlation and its shape factor. Local particle deposition sites, detailed deposition efficiencies and particle trajectories were obtained. High inertial particles tended to be filtered within the anterior regions of the cavity due to a change in direction of the airway as the air flow changes from vertical at the inlet to horizontal within the main nasal passage. Inhaled particles with pharmacological agents are often deliberately introduced into the nasal airway with a target delivery. The mucous lined airway that is highly vascular provides an avenue for drug delivery into the blood stream. An initial nasal spray experiment was performed to determine the parameters that were important for nasal spray drug delivery. The important parameters were determined to be the spray angle, initial particle velocity and particle swirl. It was found that particles were formed at a break-up length at a cone diameter greater than the spray nozzle diameter. The swirl fraction determined how much of the velocity magnitude went into a tangential component. By combining a swirling component along with a narrow spray into the main streamlines, greater penetration of larger particles into the nasal cavity may be possible. These parameters were then used as the boundary conditions for a parametric study into sprayed particle drug delivery within the CFD domain. The results were aimed to assist in the design of more efficient nasal sprays.
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De, Faria Luciano. "Airflow in the urban environment : an evaluation of the relationship between urban aspect ratios and patterns of airflow, wind velocity and direction in urban areas, and coefficient of pressure distribution on building envelopes." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/45307/.
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This thesis addresses the relationship between the physical dimensions and aspect ratios of urban areas and the airflow below the urban canopy height. The aim is to investigate the link between these aspect ratios and the resulting airflow patterns, wind speed and direction, and pressure coefficients on the envelope of target buildings. The research method involves several steps which seek to explore the airflow in four urban scenarios, simplified simulation using two parallel bricks; several complex urban prototype scenarios; and two actual urban areas used as case studies situated on the Cardiff Cathays Campus and the Paulista Avenue - São Paulo. The research methods employed are: atmospheric boundary layer wind tunnel (WT), steady-state standard k-e CFD simulation and field measurements (FM). Three prevailing wind directions were investigated: parallel, orthogonal and oblique. The outputs are guiven in terms of: Cp and ΔCp data displayed as graphs, tables and/ or contour plots; airflow patterns and velocity magnitude and direction, displayed as vertical profile graphs and visualized by means of CFD pathlines or WT helium bubble pathlines; and correlation displayed as scatter diagrams and matrices. A relationship was found between the urban aspect ratios and the ΔCp results. This was demonstrated by statistical methods using the data on the variables concerned, thus verifying the strength of the correlation between them. Strong correlation was found between the investigations into similar scenarios of the urban prototypes and the two case studies as regards both the aspect ratios and the ΔCp results. On the other hand, low correlation for the same variables were identified when contrasting dissimilar urban prototype scenarios. Moreover, good levels of comparison were found between the FM and the CFD simulations in Case Study 01 for both the decrease in wind velocity magnitude and direction in urban areas.
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Rojatkar, Prachi. "Numerical Simulation of 3-D Turbulent Room Airflow Pattern and Temperature Field in UC Solar Decathlon House." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1196019483.
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Mishuk, Aliaksandra. "Zjednodušené počítačové modely prvků pro distribuci vzduchu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372214.
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The goal of this master thesis is to create a simplified model of an actual swirl diffuser using CFD (Computational Fluid Dynamics) simulation, so that it would be easy to calculate (would have a simple geometry, a proper mesh and would enable quick definition of the model’s boundary conditions) and would also create an airflow pattern in space as close to reality as possible. In the process a CFD model with a certain geometry was created. Subsequently, various model settings were tested. Calculation results were compared with the results of the experimental measurement done using the PIV method.
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Liu, Zhao Ren, and 劉兆仁. "Measurement and simulation of airflow patterns in a prefabricated cold store." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/09247984830769918709.
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YEN, MING CHIH, and 顏銘志. "A Study on the Airflow Patterns and Improvement of a Super Clean Room." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/36375470540574705015.
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碩士國立臺北科技大學
電機與能源研究所
88
英文摘要 High technology industries such as LCD and semiconductor manufacturing, have stringent requirements on clean environment. Traditional ball room type clean room cannot meet the requirement in many cases. The new mini-environment type clean spaces are now widely used for providing ultra clean environment. Mini-environment coupled with standard mechanical interface, will become the requirement in the future 12 inch wafer processing. This research uses a vertical laminar flow buffer zone design to eliminate cross contamination in the mini-environment. The flow filed of this buffer zone is studied. Flow disturbance due to an operator was also studied. Both numerical simulation and experimental measurements were conducted to study the flow field, pressure variation, and particle concentration. The performance characteristics of this new design are discussed. Numerically, the fluid dynamic computational code FLUENT was used. Good agreements between simulations and measurements were achieved for airflow pattern, pressure variation, and particle concentration distribution. The buffer zone of laminar flow was found to be effective to avoid cross contamination with the outside environment during door opening. The height of the processing opening of the mini-environment is found to be an important factor on the flow turbulent intensity and particle concentration. Contamination due to an operator can also be reduced by this buffer zone. The results of this research are useful in the understanding of the flow characteristics in a mini-environment. The numerical techniques developed can also be used as numerical models in future studied. Key word : mini-environment, buffer zone, airflow pattern, particle concentration
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Du, Hsin-Tai, and 杜興泰. "Measurement and Analysis of Airflow Patterns in a Forced-air Cooler for Leafy Vegetables." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/80598818366621952735.
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碩士國立臺灣大學
農業機械工程學系研究所
88
Forced-air cooling is one of the most effective methods of vegetable pre-cooling, especially. In Taiwan, many produce distributions gradually adopt it. However, due to the lack of primary experimental data necessary to the design, the equipment they used is still immature and not well-designed. This research endeavors to analyze the current vegetable forced-air cooling system by experiments and computer simulation. In order to explore how forced ventilation flow is influenced by air channel of vegetable cartons and fans chamber, the research measures the turbulence characteristics of airflow by the three dimensional ultrasonic anemometer. Moreover, PHOENICS computer package modeling helps establish the data of pressure and flow fields in the system. The research offers the foundation of designing vegetable forced-air cooling equipment in the near future.
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Pelley, Brad J. "Occupational health and the analytical and numerical modeling of airflow patterns in the industrial environment /." 2003.
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Wu, Jun Wei, and 吳俊緯. "An experimental study of the effects of a moving automatic guided vehicle on airflow patterns in clean rooms." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/tfwc7h.
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碩士國立臺北科技大學
能源與冷凍空調工程系碩士班
96
A moving object, such as automatic guided vehicles (AGV), automatic stockers, or other similar loaders, destroys the uni-directional airflow patterns in clean rooms. The particles provoked by wake and vortex behind the AGV possibly contaminate the wafers or the substrate on a cassette. This research examined the influences of velocities of the airflow and the AGV, moving on the raised floor with an opening rate of 19%, on the airflow patterns, and measured the quantities of particles at the back and the top of the AGV, moving on the raised floor with opening rates of 19% and 50%, at conditions of particles released by a tool and no particle generation. This study conducted experimental measurements in a reduced-scale uni-directional clean room with a ceiling coverage rate of 100%. Results show that the wake at the back of AGV became induced airflow, and the clean downward flow suppressed the rebounded air flow from the raised floor and limited its rebounded height. The quantities of particles at the back and the top of the moving AGV were also measured at various velocities of airflow and AGV at the two opening rates of the raised floor.
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Yang, Wu-Tai, and 楊武泰. "A Study of Airflow Environment of Regular Classrooms in Primary Schools and Secondary Schools－Varied on Orientation, Patterns of Corridors, Shading Device, Windows and Railings." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/89846861624588350807.
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碩士淡江大學
建築學系碩士班
93
Abstract： The object of study in the research is airflow environment of regular classrooms in primary schools and secondary schools. Under the effect of cross ventilation, the research adopts CFD simulation to discuss airflow environment of regular classrooms influenced by variations in orientation, patterns of corridors, shading devices, windows and railings. In order to quantify the properties of ventilation to make the bases for designers proceeding architectural design, the research draws up the index from the viewpoint of the comfortable inside climate. Result： 1. The schoolhouse with a single-side corridor fanned by east wind faces south-north better than east-west. If taking one step ahead to discuss the influence of a corridor position to the airflow environment of a regular classroom, the research shows the change of the comfortable level of the airflow environment of a regular classroom is limited when the schoolhouse with a single-side corridor faces east-west; the comfortable level of the airflow environment of a regular classroom is constant when the schoolhouse with a single-side corridor faces south-north. 2. In order to improve the airflow environment of the regular classroom of the schoolhouse facing east-west with a single-side corridor located at the east side of a schoolhouse, the research suggests the designer of a regular classroom adopts the double-side corridor which width is 180cm, the combinatorial egg-crated shading device which span-to-depth ratios is 1.5, the horizon-pulled window opened dispersedly in the horizontal vector or opened a transom only in the vertical vector, and the solid railing made of reinforced concrete. 3. In order to improve the airflow environment of the regular classroom of the schoolhouse facing east-west with a single-side corridor located at the west side of a schoolhouse, the research suggests the designer of a regular classroom adopts the improved double-side corridor which width is 180cm, the combinatorial egg-crated shading device which span-to-depth ratios is 1.0, the outside-pushed window or the horizon-pulled window opened dispersedly in the horizontal vector or opened a transom only in the vertical vector, and the permeable railing. 4. In order to improve the airflow environment of the regular classroom of the schoolhouse facing south-north with a single-side corridor located at the south or north side of a schoolhouse, the research suggests the designer of a regular classroom adopts the single-side corridor which width is 300cm, the combinatorial vertical shading device which span-to-depth ratios is 1.5, the horizon-pulled window opened dispersedly in the horizontal vector, the permeable windowsill, and the solid railing made of reinforced concrete.
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Chen, Shi-Jie, and 陳世傑. "Simulation of Airflow Pattern Within the Isolation Room." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/70689879726071613804.
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碩士國立成功大學
工程科學系碩博士班
93
Due to the outbreak of SARS (Severe Acute Respirator Syndrome) in Taiwan in March of 2003, more than 15 hospitals were renovated into special hospitals for SARS patients. Isolation room is arranged for treated patients that have infectious disease. Isolation room must use special air condition and ventilation system designed to keep negative pressure in the room, so that health care worker and other patients can be protected. CDC of U.S. issued a guideline in 1994 pointing out that in order to prevent the spread of infectious disease (especially tuberculosis), isolation room is required to perform the medical treatment as well as for quarantine purposes. This thesis used FLUENT 6.1 to simulate airflow field in the isolation room. The viruses spread from the patient are modeled by carbon dioxide (CO2). Using Dynamic mesh is used to simulate the influence for health care worker walking in room. Three different position while the health care worker is walking in room are simulated in this study.
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Cheng, Tz-Yen, and 鄭子彥. "The Analysis of Kitchen Airflow Pattern and Thermal Field with Range Hood." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/78902909108226713089.
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碩士國立臺灣大學
農業機械工程學系研究所
85
An efficient range hood can rapidly remove heat, smoke and grease generated from cooking process. Kitchen airflow pattern and thermal field with range hood are important factors influencing its efficiency. In this study, both experimental and simulation approach were adopted to analyze the change of kitchen airflow pattern and thermal field with range hood. In the experimental approach, three-dimensional ultrasonic anemometers were used to measure the air velocity and T-type thermal-couples were used for temperature measurement; in the simulation approach, CFD software - CFX was used to predict the influence of using range hood in diversified circumstances. Both experimental and simulation results show that the influence of kitchen airflow pattern and thermal field with range hood is limited around the range hood. The variation of airflow pattern and thermal field is small for region beyond a distance of three times hood dimension from hood. Therefore, existence of any object in this region does not affect the range hood efficiency. During the cooking process the heat created the natural buoyancy of the heated air. If the exhaust flow quantity of range hood is not sufficient, heated air will not exhaust properly and thus will spread out to cause increase of temperature in the kitchen. In addition, the quantity of exhaust also can influence the efficiency of the range hood to collect the oil particles. Simulation of oil particle flow path was performed to analyze this phenomenon. This study not only help in understanding kitchen airflow pattern and thermal field with range hood, but also offer an model for range hood design and installation.
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Ching, Han-Hsi, and 青含璽. "Measurement and Simulation of Airflow Pattern in a Prefabricated Center-Ceiling Evaporator." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/14172073930053152429.
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碩士國立臺灣大學
農業機械工程學系
84
Cold stores play an important part in food preservation; It is very important to understand the factors which affect the quality of products in cold stores. From literatures,the flow pattern of flow field will directly influence the temperature distribution in cold stores , and ill temperature distribution is the main factor that will cause damage to products in the cold stores. In the study,both experimental and numerical approaches were adopted to analyze the airflow characters in the prefabricated cold store. In the experimental approach , three dimensional ultrasonic anemometer was used to measure the turbulent characters in the flow field , T-type thermal-couples to obtain the temperature distribution;In simulative approach ,the FLOW-3D software and experimental consequences were used to simulate the prefabricated cold store. Moreover, the airflow characters could be improved or predicted under different loading conditions.