A aviação comercial vem experimentando expressivo crescimento com elevado grau de competitividade. Produzir aeronaves com nível de conforto diferenciado transformou-se em importante ferramenta de marketing e de venda. Esta, porém, não é tarefa fácil. Cabines de aeronave apresentam condições de escoamento e de trocas térmicas que tornam bastante difícil prover e avaliar condições de conforto térmico. Para tentar resolver o problema, estudos estão sendo realizados em centros de pesquisa, em colaboração com a indústria aeronáutica. O presente trabalho se insere neste contexto. Neste trabalho foi realizado estudo do escoamento em cabine de aeronave, por meio de medição de variáveis ambientais de cabine, e de conforto térmico utilizando manequim térmico instrumentado e avaliação com pessoas. Para a realização dos ensaios foi projetado e construído mock-up de seção de cabine com 12 lugares. Foram analisadas condições do escoamento e de conforto térmico para duas condições de cabine, 19 e 24 °C. Nos ensaios com pessoas participaram 11 voluntários. Temperaturas equivalentes foram determinadas utilizando-se manequim térmico instrumentado e apresentadas em diagrama de sensação térmica previsto para este fim em norma técnica de veículos. Posteriormente, avaliações subjetivas, com resultados apresentados em diagramas de voto térmico médio (VTM) e de voto de conforto médio (VCM), foram realizadas. Verificou-se que, apesar das condições complexas do escoamento, não ocorreram diferenças significativas de velocidade do ar na região de ocupação e nem de temperatura na direção vertical, que são fatores que poderiam ocasionar grande desconforto. Verificou-se também a ocorrência de uma boa aproximação entre as avaliações de conforto térmico feitas por meio das temperaturas equivalentes e os resultados das análises subjetivas realizadas por meio de questionários. Nas avaliações subjetivas ocorreu um pequeno deslocamento dos resultados para o lado direito no diagrama de VTM. Finalmente, verificou-se que as pessoas preferiram as condições de cabine na temperatura de 19 °C, com votos de conforto médio (VCM) de indiferentes a ligeiramente confortáveis, enquanto na temperatura de cabine de 24 °C as condições foram consideradas ligeiramente desconfortáveis. / The commercial aviation has experienced an expressive growth with a high degree of competitiveness. The production of aircrafts with a higher comfort level has become an important tool for marketing and trading. However, this is not an easy task. Aircraft cabins present airflow and thermal transfer conditions that make quite difficult to provide and to evaluate thermal comfort conditions. In order to try to solve this problem, studies are being performed in research centers, in collaboration with the aeronautical industry. This project is inserted in this context. In this project a study of aircraft cabin airflow, through the measurement of the cabin environmental variables, and the thermal comfort using thermal mannequin and evaluation with people, was accomplished. For the accomplishment of the tests a mock-up of a cabin section with 12 places was projected and built. Conditions of airflow and thermal comfort within two cabin conditions, 19 and 24 °C, were analyzed. The tests with people were performed by 11 volunteers. Equivalent temperatures were obtained by using a thermal mannequin and were presented in a thermal sensation diagram, which had been seen to this purpose in vehicles technical norm. Later on, subjective evaluations, whose results were presented by an mean thermal vote (MTV) diagram and by an mean comfort vote (MCV) diagram, were accomplished. It was verified that, in spite of the complex airflow conditions, significant differences neither of the air velocity in the occupation area nor of the temperature in the vertical direction happened, which are factors that could cause a great discomfort. It was also verified a strong relation between thermal comfort evaluations accomplished through the equivalent temperatures and the results of the subjective analyses accomplished through questionnaires. In the subjective evaluations, a small displacement of the results to the right side in the MTV diagram occurred. Finally, it was verified that the volunteers preferred 19 °C temperature cabin condition, with mean comfort votes (MCV) indicating from indifferent to lightly comfortable conditions, while in the 24 °C cabin the conditions were considered lightly uncomfortable.

No description available.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第24660号 / 農博第2543号 / 新制||農||1098(附属図書館) / 学位論文||R5||N5441(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 大村 和香子, 教授 藤井 義久, 教授 今井 友也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Computational Fluid Dynamics (CFD) refers to numerical methods for simulating the movement of fluid. Due to its efficiency, CFD has been widely used in aerospace engineering and automotive design since the 1970s. It also has potential in architectural design since airflow has been an important player in the design process. However, the CFD users in the building industry tend to be limited to researchers and engineers rather than architectural designers due to the complexity of the simulations including the extensive knowledge required for the processing. The benefit of using CFD would be maximized through its early application by architectural designers since the key design decisions are made in the early stages. In response to this, simulation tools specialized for the early stages of architectural design are developed recently, which offer more user-friendly interfaces. Within this context, the present study aimed to introduce and test the simulation tools for the early stages of design and establish a framework for supporting architectural designers to utilize CFD. Under this objective, a mixed-method approach was employed that includes quantitative and qualitative assessments of simulation tools, development of a knowledge set that can help the users to understand the simulation processes and results, an immersive case study for structuring the procedural model, and a Delphi method for evaluating and reaching a consensus on the proposed framework. / Doctor of Philosophy / Computational Fluid Dynamics (CFD) is a computer simulation method for automating the calculations of the complex equations on the flow of a fluid, such as air or water, and visualizing the calculation results. CFD has been widely used in designing aircraft and cars since the 1970s because of the efficiency of this method compared to physical experiments. CFD also has potential in architectural design since airflow has been an important player in the design process. However, the CFD users in the building industry tend to be limited to researchers and engineers rather than architectural designers due to the complexity of the simulations including the extensive knowledge required for the processing. In response to this situation, more user-friendly simulation tools for non-experts, including designers, are developed recently. Considering this context, the present study tried to introduce and test the simulation tools for designers and develop a framework for supporting architectural designers to utilize CFD in their design processes. Under this objective, both quantitative and qualitative studies were conducted, including the review of relevant articles, computer simulations, a case study with an architectural project example, designed by the author, and a Delphi method in which the recruited experts in architectural design evaluate the proposed framework.

Human thermal environments constitute complex combinations of various interacting thermal factors. The transient and non-uniform nature of those thermal factors further increases the complexity of the thermal comfort problem. The conventional approach to the thermal comfort problem has been simplifying the problem and providing steady thermal environments which would satisfy the majority of the people in a given space. However, several problems emerged with this approach. People became finely tuned to the narrow range of conditions and developed expectations for the same conditions which made them uncomfortable when there were slight deviations from those conditions. Also, the steady approach didn't solve the comfort problem because, in practice, people move between spaces, and thermal conditions such as metabolic rate, surface temperatures, airflow speed and direction vary in a typical day. A human subject test was designed to determine the transient relationship between the people and their environments. In the first part, thermal perceptions of people were taken during various metabolic rate conditions. In the second and the third parts, transient conditions of different thermal factors were created. Various combinations of airflow frequencies, airflow location around the body, metabolic rate, and room temperatures were tested for their individual and interaction effects of providing thermal comfort. The concept of Localized Dynamic Airflow was proposed in which room airflow was simply redirected to different parts of the body with a varying airflow speed. Results showed that males and females respond differently to the thermal conditions. The room temperatures they found neutral were significantly different. People‟s thermal comfort during transient metabolic conditions was similar to high metabolic conditions. This heightened response extended into the next ten minutes after the high metabolic conditions ended. Test results suggested that people tolerate higher temperatures during transient environmental conditions. The average response was for comfortable even during the high temperature (83°F) and high metabolic rate (4 met) conditions. Low energy use of the localized dynamic airflow and the increased room temperatures has significant potential for monetary savings.

Doctor of Philosophy / Architects have long been focused on designing eco-friendly buildings, but there's a growing realization that focusing solely on energy efficiency isn't enough. Occupants spend the majority of their time indoors, and the quality of these indoor spaces profoundly impacts their well-being and productivity. Yet, often overlooked, are factors like lighting, air quality, and noise that can significantly affect how occupants feel and perform. With rising urbanization and recent experiences during the COVID-19 pandemic highlighting the importance of indoor environments, there's a renewed emphasis on user-centric design. Biophilic design, which incorporates elements of nature into buildings, has emerged as a promising approach to enhancing occupants' health, wellness, and well-being. Airflow, a critical aspect of biophilic design, plays a key role in creating healthier indoor spaces. This study aims to develop a prototype system that mimics natural airflow patterns indoors to promote occupants' health and well-being. By analyzing weather data, natural airflow features were identified and used to inform the design of a mechanical system. The goal is to create settings that replicate natural airflow patterns in indoor environments. Ultimately, this research lays the groundwork for future studies to explore how such biophilic systems impact occupants' physiological and psychological health. By prioritizing user experience in building design, indoor spaces that not only conserve energy but also enhance the quality of life could be developed.

Within the company Infinera, there is a need for an improved thermal design of an existing chassis product for use in telecommunications for distribution of services within the Edge & Metro network. To enable an optimized airflow design of the chassis, there is a need of analyzingdifferent simulation cases performed in FloTHERM. Mechanical and electrical airflow design has been examined in different cases that cover the system requirements.Thermal analyzes of the product have been performed using the FloTHERM tool, and changes and improvements to the design have been performed via the CAD SolidWorks software tool.Problem formulation for this thesis is to further develop the design of the chassis for improved airflow for electrical and optical components that are placed in an existing chassis for the temperature range of 0-70 ℃ according to the industry standard NEBS (Level 3). The slot-in card has been analyzed in a worst-case scenario to identify the most critical components on the PCB board. The result that has been achieved is six different simulation cases with different airflow designs and models of fans that are adapted to today's existing chassis. An updated final version based on simulation results has been modeled as a proposal for the product in the CAD program. A 2D drawing of the design of the product is included as an appendix.The conclusion of this work has shown an improved airflow design on a chassis with a side-byside airflow configuration with the use of four replaceable fans within a fan bay. A bypass block ontop of the cover has shown good results as a cooling method on electrical and optical components. In this work, due to limited time, the bypass block has not been completed as a 3D modeling part. This will be continued as a suggested future work. In addition, a front-to-side airflow design has been analyzed in FloTHERM, this can also be further developed and investigated in more detail in future work for an optimized airflow design of the chassis.Keywords: Airflow systems for electronics, thermal management, telecommunication equipment, airflow resistance, cooling of electronics. Keywords: Airflow systems for electronics, thermal management, telecommunication equipment, airflow resistance, cooling of electronics. / Inom företaget Infinera finns det ett behov av en förbättrad termisk design av en existerande chassiprodukt för användning inom telekommunikation för distribution av tjänster inom Edge &Metro nätverk. För att kunna optimera luftflödet av chassit behövs termiska simuleringar utförastillsammans med mekaniska och elektroniska designflöden för att kunna undersöka luftflödet i olika situationer som täcker systemkraven. Termiska analyser på produkten har utförts genom simuleringsverktyget FloTHERM, samtförändringar och förbättringar av konstruktionen har utförts via programverktyget CAD SolidWorks. Problemformulering för det här examensarbetet är att vidareutveckla designen för chassit för ett förbättrat luftflöde för elektriska och optiska komponenter som placeras i ett existerande chassitför temperaturområdet 0–70 ℃. Samt att chassit förhåller sig till bransch standarden NEBS (Nivå 3) och analyseras i värsta utfallscenariot av ett slott-in kort.Det resultat som har uppnåtts är sex olika utfall av chassit med olika luftflödes design och modeller av fläktar som är anpassade för dagens chassiprodukt med uppföljda kravkriterier. En uppdaterad slutgiltig version baserat på simuleringsresultat har modellerats som förslag på produkten i CAD programmet. En 3D ritning på designen av produkten medföljs som bilaga. Slutsatsen för det här arbetet i syfte till ett förbättrad luftflödes design är ett chassi med en sida-tillsida luftflödes design med fyra utbytbara fläktar i ett utbytbart fläktpaket. Ett nedsänkt tak i chassit ovanför kortet har visat goda resultat som en kylningsmetod på elektriska och optiska komponenter. I detta arbete, på grund av begränsad tid, har ett nedsänkt tak inte fullföljts som en 3D modellering som en tillhörande del av chassit. Ett sänkt innertak kommer att behövaskompletteras i ett fortsatt arbete för framtiden. Även en luftflödesdesign som har undersökts framifrån-till-sida av chassit i FloTHERM kan vidareutvecklas och undersökas närmare i ett framtida arbete för en optimerad luftflödesdesign av chassi produkten. Nyckelord: Luftflödessystem för elektronik, termisk hantering, telekommunikations applikationer, luftflödesmotstånd, kylning av elektronik. Nyckelord: Luftflödessystem för elektronik, termisk hantering, telekommunikations applikationer, luftflödesmotstånd, kylning av elektronik

No description available.

<p>One of the most fundamental human needs is fresh air. It has been estimated that people spend comparatively much time in indoor premises. That creates an elevated need for high-quality ventilation systems in buildings. The ventilation airflow rate is recognised as the main parameter for measuring the indoor air quality. It has been shown that the ventilation airflow rates have effects on respiratory diseases, on “sick building syndrome” symptoms, on productivity and perceived air quality. Ventilation is necessary to remove indoor-generated pollutants by diluting these to an acceptable level. The choice of ventilation airflow rate is often based on norms or standards in which the airflow rate is determined based on epidemiological research and field or laboratory measurements. However, the determination of ventilation flow rate is far more complex. Indoor air quality in the occupied zone can be dependent of many factors such as outdoor air quality, airflow rate, indoor generation of pollutants, moisture content, thermal environment and how the air is supplied into the human occupied zone. One needs to acknowledge the importance of air distribution which clearly affects the comfort of occupants. To design a ventilation system which considers all aspects of room ventilation can only be achieved by computer modelling. The objective of this thesis is to investigate air diffusion, indoor air quality and comfort issues by CFD (computational fluid dynamics) modelling. The crucial part of the CFD modelling is to adopt BCs (boundary conditions) for a successful and accurate modelling procedure. Assessing the CFD simulations by validated BCs enabled constructing the ventilation system virtually and various system layouts were tested to meet given design criteria. In parallel, full-scale measurements were conducted to validate the diffuser models and the implemented simplified particle-settling model. Both the simulations and the measurements reveal the full complexity of air diffusion coupled with solid contaminants. The air supply method is an important factor for distribution of heat, air velocity and solid contaminants. The influence of air supply diffuser location, contaminant source location and air supply method was tested both numerically and by measurements to investigate the influence of different parameters on the efficiency of room ventilation. As example of this, the well-known displacement ventilation is not fully able to evacuate large 10 μm airborne particles from a room. Ventilation should control the conditions in the human breathing zone and therefore the ventilation efficiency is an important parameter. A properly designed ventilation system could use less fresh air to maintain an acceptable level of contaminant concentration in the human breathing zone. That is why complete mixing of air is not recommended as the ventilation efficiency is low and the necessary airflow rate is relatively high compared to other ventilation strategies. Especially buoyancy-driven airflows from heat sources are an important part of ventilation and should not be hampered by supply airflow from the diffusers. All the results revealed that CFD presently is the only reliable method for optimising a ventilation system considering the air diffusion and contaminant level in all locations of any kind of room. The last part of the thesis addresses the possibility to integrate the CFD modelling into a building design process where architectural space geometry, thermal simulations and diffuser BCs could be embedded into a normal building design project.</p>

Arbetet handlade om att utreda energibehovet till följd av en industriport mellan ett fryslager och en utlastningsterminal, samt utreda om anläggningens golvvärme kan arbeta med sänkt temperatur för att minska uppvärmingen av fryslagret, båda delarna med syftet att identifiera energiförluster och kunna sänka energiåtgången. Energiförlusten till följd av porten identifierades genom uppmätning av luftflöden för att sedan beräknas över ett år med hjälp av en teoretisk modell. För att undersöka golvvärmens driftsparametrar gjordes en litteraturstudie för att bestämma ifall det vore tillrådligt att sänka dess arbetstemperatur. Slutsatsen blev att portens öppetvarande under år 2016 resulterade i omkring 145MWh i rent termisk energiförlust. Anläggningens vattenburna golvvärme drivs vid cirka 10-12°C vilket är enligt praxis och att en förändring av temperaturen därför inte kan rekommenderas. / This thesis was examining the energy demand due to an industrial gate dividing a freezer warehouse and it’s adjacent loading bay, as well as determining whether the facility’s sub-floor heating could be operated at a lower temperature setting in order to decrease the heat transfer into the freezer, both of which with the purpose to identify energy losses and possibly lower the total energy demand. The energy losses due to the gate were identified by measuring airflow and then calculate the loss over a whole year by means of a theoretical model. To examine the operating parameters of the sub-floor heating, a literature study was conducted in order to determine whether it would be feasible to lower its temperature. The conclusion was that the opening of the gate during year 2016 resulted in about 145MWh of purely thermal energy loss. The facility’s waterborne sub-floor heating is operated at around 10-12°C, which is according to practice, and a change of temperature cannot be recommended.