Dissertations / Theses on the topic 'Insulation (Heat) Thermal properties'
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Kianzad, Siamak. "Measurement of Thermal Insulation properties of TBC inside the Combustion chamber." Thesis, Luleå tekniska universitet, Materialvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-61917.
Full textFrye, Elora. "Material Thermal Property Estimation of Fibrous Insulation: Heat Transfer Modeling and the Continuous Genetic Algorithm." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5433.
Full textRauchfussová, Karolína. "Studium užitných vlastností tepelně-reflexních izolací pro stavebnictví." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-295661.
Full textSamek, Josef. "Optimální plnění drážky s ohledem na použitou izolaci motoru a pracovního zatížení." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-256525.
Full textAghahadi, Mohammad. "Etude expérimentale et modélisation physique des transferts couplés chaleur-humidité dans un isolant bio-sourcé." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCA007/document.
Full textThe conventional heat transfer models are not sufficiently suitable for thermal characterization of bio-sourced thermal insulating materials due to their strongly hydrophilic nature. The proposed work in this PhD thesis aims to answer this problem with experimental and theoretical approaches of coupled heat-moisture transfers. In the experimental approach, a thermal insulating material based on Flax Fiber Felt (FFF) is developed and then characterized at different hygrometric conditions with an asymmetric hot plate device. The humidity diffusion characterization of the samples is done using the GAB, GDW and Park theoretical moisture adsorption isotherm models. In the theoretical approach, a physical model of heat and mass transfer is proposed. It is solved numerically, in transient 3D configuration, by the finite element method under COMSOL Multiphysics and, in transient 1D configuration, by the finite difference method under MATLAB. The Levenberg-Marquardt method coupled with the 1D transient direct model and the measured temperatures made it possible to estimate the apparent thermal conductivity of the studied sample with a relative error of less than 6% compared to the experimental measurements, thus validating the theoretical models
Cohen, Ellann. "Thermal properties of advanced aerogel insulation." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67795.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 74-76).
Buildings consume too much energy. For example, 16.6% of all the energy used in the United States goes towards just the heating and cooling of buildings. Many governments, organizations, and companies are setting very ambitious goals to reduce their energy use over the next few years. Because the time periods for these goals are much less than the average lifetime of a building, existing buildings will need to be retrofitted. There are two different types of retrofitting: shallow and deep. Shallow retrofits involve the quickest and least expensive improvements often including reducing infiltration around windows, under doors, etc and blowing more insulation into the attic. Deep retrofits are those that involve costly renovation and typically include adding insulation to the walls and replacing windows. A new, easily installable, inexpensive, and thin insulation would move insulating the walls from the deep retrofit category to the shallow retrofit category and thus would revolutionize the process of retrofitting homes to make them more energy efficient. This thesis provides an overview of a concept for a new, easily installable, inexpensive, thin aerogel-based insulation and goes into detail on how the thermal properties of the aerogel were measured and validated. The transient hot-wire method for measuring the thermal conductivity of very low thermal conductivity silica aerogel (1 0mW/m K at 1 atm) along with a correction for end effects was validated with the NIST (National Institute of Standards and Technology) Standard Reference Material 1459, fumed silica board to within 1 mW/mK. Despite the translucence of the aerogel at certain wavelengths, radiation is not an issue through the aerogel during the hot-wire test but may be an issue in actual use as an insulation. The monolithic aerogel thermal conductivity drops significantly with slightly reduced pressure (3.2 mW/m K at 0.1atm). For the final composite insulation, the new silica aerogel formula is a great choice and it is recommended to reduce the pressure around the aerogel to 1 / 1 0 th. In the future, a prototype of an insulation panel combining a 3-D truss structure, monolithic or granular silica aerogel, and reduced pressure will be constructed and tested.
by Ellann Cohen.
S.M.
Lamberts, R. "Heat transfer through roofs of low cost Brazilian houses." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383003.
Full textJohnson, Wesley Louis. "Thermal performance of cryogenic multilayer insulation at various layer spacings." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4681.
Full textID: 029050581; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.A.E.)--University of Central Florida, 2010.; Includes bibliographical references (p. 79-85).
M.S.A.E.
Masters
Department of Mechanical, Materials and Aerospace Engineering
Engineering and Computer Science
Aerospace Engineering
Mahasaranon, Sararat. "Acoustic and thermal properties of recycled porous media." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5516.
Full textNeugebauer, Adam (Adam Halbert). "Thermal properties of granular silica aerogel for high-performance insulation systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85213.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 65-67).
Based on mounting evidence in support of anthropogenic global climate change, there is an urgency for developments in high-performance building techniques and technologies. New construction projects provide substantial opportunities for energy efficiency measures, but they represent only a small portion of the building stock. Conversely, while existing buildings are plentiful, they typically have a much narrower range of feasible energy efficiency options. Therefore, there will continue to be a need for the development of new and improved energy efficiency measures for new building construction and even more so for deep retrofits of existing buildings. This thesis provides an overview of the research performed into the on-going development at MIT of a high-performance panelized insulation system based on silica aerogel. Two test methods were used for measuring the thermal conductivity of the granules: the transient hot-wire technique and the guarded hot-plate system. Utilizing the hot-wire set-up, it was demonstrated that compressing a bed of granules will decrease the thermal conductivity of the system until a minimum point is reached around the monolithic density of the aerogel. For the Cabot granules, this was seen at 13 mW/m-K and about 150 kg/m3. The MIT granules showed equal performance to the Cabot granules at bed densities 20-30 kg/m3 lower. The hot-plate testing was able to experimentally evaluate previous analytical predictions regarding the conductivity impact of the internal panel truss and the under-prediction of radiant heat transfer in the hot-wire method. Hot-wire testing was also done in a vacuum chamber to quantify potential performance improvements at reduced air pressures. Since a vacuum would require the incorporation of a barrier film into the panel system, some analyses were done into the thermal bridging potential and gas diffusion requirements of such a film. Additionally, physical prototyping was done to explore how the film would be incorporated into the existing panel design. The aerogel-based insulation panel being developed at MIT continues to show promise, though there are still plenty of opportunities remaining in the development cycle.
by Adam Neugebauer.
S.M. in Building Technology
Chiu, Kwong-Shing Kevin. "Temperature dependent properties and microvoid in thermal lagging /." free to MU campus, to others for purchase, 1999. http://wwwlib.umi.com/cr/mo/fullcit?p9962510.
Full textWegger, Erlend. "Ageing effects on thermal properties and service life of vacuum insulation panels." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bygg, anlegg og transport, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11808.
Full textVakuumisolasjonspaneler (VIP) er en høyisolerende materialløsning som kan være et alternativ til tradisjonell bygningsisolasjon. På grunn av god isolasjonsevne kan man ved bruk av VIP redusere veggtykkelsen og fortsatt tilfredsstille energikravene som stilles til moderne bygninger. En av de viktigste egenskapene for VIP er evnen til å bevare høy termisk ytelse over tid. I den sammenheng har aldringseffekter for VIP blitt undersøkt. Siden laboratoriestudier av aldringseffekter gjøres i løpet av et relativt kort tidsrom, er akselerert aldring nødvendig for å få evaluert termiske egenskaper over tid. Det finnes pr. i dag ingen standardisert metode for akselerert aldring av VIP. Det finnes likevel flere studier av sammenheng mellom klimaforhold og VIP egenskaper. Spesielt er gass og fuktdiffusjon inn i panelet behandlet grundig i litteraturen. Basert på dette er det foreslått flere mulige faktorer for aldring av VIP. De faktorene som er funnet å bidra mest til aldring av VIP er temperatur, fuktinnhold i lufta og utvendig lufttrykk. Ved å variere disse faktorene er fire forskjellige aldringsforsøk beskrevet og gjennomført.Konduktivitetsmålinger er blitt brukt som et mål på de termiske egenskapene til de testede VIPene. De forskjellige forsøkene viste forskjellig grad av aldringseffekt. Generelt var endringen i konduktivitetsverdier liten. Resultatene indikerer at akselerasjonseffekten var innenfor hva som kan forutsies fra de teoretiske sammenhengene. Likevel er det vanskelig å trekke noen definitive konklusjoner, både siden endringen var så liten, og fordi få paneler ble brukt i forsøkene. Noen fysiske endringer ble observert under forsøkene. Blant annet este et av panelene noe ut, mens et annet bøyde seg permanent. Man burde likevel ikke legge for mye vekt på disse effektene, siden de kan skyldes de relativt ekstreme testforholdene.
Grange, Peter James Christopher. "Investigating the Commercial Viability of Stratified Concrete Panels." Thesis, University of Canterbury. Department of Civil and Natural Resources Engineering, 2012. http://hdl.handle.net/10092/7430.
Full textHobbs, Martin K. "The structure and properties of plasma-sprayed 8% yttria-zirconia thermal barrier coatings." Thesis, University of Bath, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234081.
Full textBoissonnet, Germain. "Factors influencing the thermal insulation potential of different thermal barrier coating systems." Thesis, La Rochelle, 2019. http://www.theses.fr/2019LAROS007.
Full textIn aeronautical gas turbine engines, the metallic materials employed in the hottest sections are subject to very harsh chemical environments at high pressures and temperatures. Therefore, thermal barrier coating systems (TBCs) are applied onto nickel-based superalloy substrates. These multi-layered systems (ceramic yttria-stabilized zirconia (YSZ) / MCrAl or NiPtAl bond coats / cooled substrate) lower the temperature at the components surface, which ensures an adequate thermomechanical behaviour and reduces the oxidation/corrosion rates. However, the increase of the turbine inlet temperature (increased engine performance) brings about new degradation phenomena (e.g. CMAS) and loss of efficiency of the current TBCs. Therefore, understanding the evolution of the insulation ability of TBCs in such harsh environments is key from both the scientific and technological perspectives to estimate the lifetime of these coatings, hence that of the engines. Based on current plasma-sprayed (PS) and electron-beam physical vapour deposited (EB-PVD) YSZ coatings, this thesis seeks to provide a better comprehension on the relationships between the intrinsic properties of the current TBCs and their thermal insulation capacity as a basis for the development of future coatings. Also, this work studies an alternative solution to create a TBC made of hollow alumina microspheres by the slurry route. We will show that the sintering of the YSZ, the evolution of crystal phases, the reactions between YSZ and CMAS and the growth of thermal oxides alter the thermal diffusivity to different extents. In contrast, the evolution of the thermal diffusivity with temperature is less marked with the slurry alumina coatings, which appear more stable when hybrid Ar/air annealing atmospheres are employed upon their synthesis
Santhosh, Balanand. "Thermal properties of polymer derived Si-O-C-N ceramics." Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/267913.
Full textHussain, Atif. "Enhancement of hygrothermal properties of bio-based thermal insulation materials via sol-gel technology." Thesis, University of Bath, 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.767569.
Full textMigwi, Charles Maina. "Thermophysical properties of elastomers." Thesis, University of Salford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261858.
Full textKim, Taehwan. "Preventing Thermal Degradation of Pvc Insulation by Mixtures of Cross-Linking Agents and Antioxidants." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157547/.
Full textAndruskiewicz, Peter Paul. "ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF TEMPERATURE-SWING INSULATION ON ENGINE PERFORMANCE." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/90467.
Full textLos materiales aislantes han sido investigados a fondo por sus posibles mejoras en la eficiencia térmica de los motores de combustión interna alternativos. Estas mejoras se ven reflejadas tanto directamente en el trabajo indicado como indirectamente a través de la reducción del sistema de refrigeración del propio motor. Diferentes estudios, tanto experimentales como analíticos, han mostrado la reducción en la transferencia de calor a través de las paredes de la cámara de combustión mediante la utilización de estos materiales. Sin embargo, demostrar la conversión de la energía térmica adicional en trabajo indicado ha resultado más difícil. En ciertos estudios se pudieron obtener mejoras en el trabajo indicado durante la carrera de expansión, pero éstas fueron reducidas debido a un menor rendimiento volumétrico debido al calentamiento de la carga durante el proceso de admisión y un mayor trabajo en la carrera de compresión. Típicamente, las únicas mejoras en el trabajo al freno provendrían de la reducción de pérdidas por bombeo en los motores turboalimentados, o de la extracción de la energía adicional de los gases de escape a través de turbinas. El concepto de los materiales con oscilación de la temperatura durante el ciclo motor intenta aprovechar los beneficios del aislamiento durante los procesos de combustión y expansión, mitigando las perdidas por el incremento de la temperatura de las paredes durante la admisión y la compresión. La combinación de baja capacidad calorífica y baja conductividad térmica permitiría que la temperatura de la superficie de la cámara de combustión respondiera rápidamente a la temperatura del gas durante el proceso de combustión. Las temperaturas de la superficie son capaces de aumentar en respuesta al pico de flujo de calor, minimizando así la diferencia de temperatura entre el gas y la pared en la carrera de expansión cuando es posible la mayor conversión de energía térmica en trabajo mecánico. La combinación de baja capacidad calorífica y conductividad térmica es también esencial para permitir este aumento de temperatura durante la combustión y para permitir que la superficie se enfríe durante la expansión y el escape para no perjudicar así el rendimiento volumétrico del motor durante la carrera de admisión y minimizar el trabajo de compresión realizado en el siguiente ciclo. En esta tesis se han desarrollado modelos térmicos y termodinámicos para predecir los efectos de las propiedades de los materiales en las paredes y caracterizar los efectos de la transferencia de calor en diferentes partes del ciclo sobre el trabajo indicado, el rendimiento volumétrico, la energía en los gases de escape y las temperaturas del gas para un motor de combustión interna alternativo. También se ha evaluado el impacto del uso de estos materiales en el knock en motores de combustión de encendido provocado, ya que los estudios experimentales de esta tesis se realizaron en un motor de estas características. Durante la investigación se evaluaron materiales aislantes convencionales para comprender el estado actual de esta técnica y para adquirir también experiencia en el análisis de materiales aislantes con oscilación de temperatura. Desafortunadamente, los efectos de la permeabilidad a través de la porosidad del material en los recubrimientos convencionales, la absorción de combustible y la relación de compresión tendieron a ocultar los efectos de la oscilación de la temperatura y la reducción de la transferencia de calor a través de las paredes. Así pues, se analizó el impacto individual de cada uno de estos mecanismos y su influencia en el rendimiento del motor para así definir un nuevo material con las características necesarias que mejorasen el aislante con de oscilación de temperatura. Finalmente, a partir de los estudios de esta fase de análisis, se creó un nuevo material y se aplicó a la superficie del pistón y a la supe
Els materials aïllants han estat investigats a fons per les seves possibles millores en l'eficiència tèrmica en el motors de combustió interna alternatius. Aquestes millores es veuen reflectides tant directament en el treball indicat com indirectament a través de la reducció del sistema de refrigeració del propi motor. Diferents estudis, tant experimentals com analítics, han mostrat la reducció en la transferència de calor a través de les parets de la cambra de combustió mitjançant la utilització d'aquests materials. No obstant això, demostrar la conversió de l'energia tèrmica addicional en treball indicat ha resultat més difícil. En certs estudis es van poder obtenir millores en el treball indicat durant la carrera d'expansió, però aquestes van ser reduïdes a causa d'un menor rendiment volumètric causat de l'escalfament de la càrrega durant el procés d'admissió i un major treball en la carrera de compressió. Típicament, les úniques millores en el treball al fre provindrien de la reducció de pèrdues per bombeig en els motors turbo alimentats, o de l'extracció addicional de l'energia dels gasos d'escapament a través de turbines. El concepte dels materials amb oscil·lació de la temperatura durant el cicle motor intenta aprofitar els beneficis de l'aïllament durant els processos de combustió i expansió, mitigant les perdudes per l'increment de la temperatura de les parets durant l'admissió i la compressió. La combinació de baixa capacitat calorífica i baixa conductivitat tèrmica permetria que la temperatura de la superfície de la cambra de combustió respongués ràpidament a la temperatura del gas durant el procés de combustió. Les temperatures de la superfície són capaços d'augmentar en resposta al flux de calor, minimitzant així la diferència de temperatura entre el gas i la paret en la carrera d'expansió quan és possible la major conversió d'energia tèrmica en treball mecànic. La combinació de baixa capacitat calorífica i conductivitat tèrmica és també essencial per permetre aquest augment de temperatura durant la combustió i el refredament de la superfície durant l'expansió i l'escapament per no perjudicar així el rendiment volumètric del motor durant la carrera d'admissió i minimitzar el treball de compressió realitzat en el següent cicle. En aquesta tesi s'han desenvolupat models tèrmics i termodinàmics per predir els efectes de les propietats dels materials en les parets i caracteritzar els efectes de la transferència de calor en diferents parts del cicle sobre el treball indicat, el rendiment volumètric, l'energia en els gasos d'escapament i les temperatures del gas per un motor de combustió interna alternatiu. També s'ha avaluat l'impacte d'aquests materials en el knock en motors de combustió d'encesa provocada, ja que les proves experimentals d'aquesta tesi es van realitzar en un motor d'aquestes característiques. Durant la investigació es van avaluar materials aïllants convencionals per comprendre l'estat actual d'aquesta tècnica i per adquirir també experiència en l'anàlisi de materials aïllants amb oscil·lació de temperatura. Desafortunadament, els efectes de la permeabilitat a través de la porositat del material en el recobriment convencional, l'absorció de combustible i la relació de compressió van tendir a ocultar els efectes de l'oscil·lació de la temperatura i la reducció de la transferència de calor a través de les parets. Així doncs, es va analitzar l'impacte individual de cada un d'aquests mecanismes i la seva influència en el rendiment del motor per així definir un nou material amb les característiques necessàries que milloressin el aïllant d'oscil·lació de temperatura. Finalment, a partir dels estudis d'aquesta fase d'anàlisi, es va crear un nou material i es va aplicar a la superfície del pistó i a la superfície interna de les vàlvules d'admissió i d'escapament. Les dades de motor es van prendre a
Andruskiewicz, PP. (2017). ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF TEMPERATURE-SWING INSULATION ON ENGINE PERFORMANCE [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90467
TESIS
Schaefer, Laura Atkinson. "Heat exchanger mean temperature differences for refrigerant mixtures." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/18938.
Full textHand, Daniel Quincy 1956. "Three-dimensional heat conduction in laminated anisotropic solids." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276749.
Full textVan, Wyk Peter Arnold. "Thermal management and control of space satellite systems and subsystems in orbit." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/49738.
Full textENGLISH ABSTRACT: The focus of this thesis is on South Africa's first micro space satellite SUNSAT, and the thermal modelling thereof. Background theory with relevance to thermal management and control of satellite systems and subsystems is presented. The mission profile and subsystem makeup of SUNSAT is also briefly discussed, with emphasis placed on the physical structure, possible orbit paths, internal heat generation, and the environmental heating. The environmental heating on the satellite surfaces from the direct and reflected earth solar radiation, as well as the earth emitted infrared radiation, is determined from the developed computer program ORBIT-FLUX. This program was used in tandem with numerical programs (developed in house), as well as an outsourced program TAS (Thermal Analysis Systems) to model SUNSAT for two possible orbit paths. The resistance-capacitance formulation method was used to develop the numerical programs, which served initially to establish the validity ofTAS. The first approximated thermal model of SUNSA T's batteries was the 7 lumped-mass model that focused on the batteries since their overheating is the suspected reason for SUNSA T'S failure to complete its mission. A numerical program as well as a similar TAS model was developed, and the results showed correlation to within 3°C. A lumped-mass model of SUNSAT was also developed, both numerically and using TAS. The models were tested and the results showed that the temperatures of the models were sensitive to changes in internal heating as well as varying emissivity and absorptivity. The numerical and TAS lumped-mass model results did not correlate well, possibly due to the higher number of control volumes used in the TAS lumped-mass model. The TAS SUNSAT 2 model was developed as advancement on the lumped-mass model. The higher number of control volumes and the effect of adding solar panels gave a more realistic model of SUNSA T. The results did not show good correlation with actual SUNSA T temperature data possibly due to the fact that the solar panels were not mounted on the model body as they were on SUNSA T; but the TAS SUNSA T 2 model did set the platform for the more advanced TAS SUNSAT 3 model. This thermal model included the effects of the solar panel mountings, and had a higher number of control volumes, which gave a better physical representation of the SUNSAT subsystems. The model was tested for possible orbit paths of SUNSA T. The results showed excellent correlation to actual SUNSA T data. For the comparison of the TAS SUNSA T 3 model results with data from SUNSAT for July 1999 showed that the SUNSA T battery temperature was modelled to within 8°C. And for June 2000, this same comparison was to within 1°C. A thermal management and control case study was done on a simple system (which included a cubic box and an internal solid block with heat generation) to illustrate the effects of using various passive and active thermal control hardware to regulate temperatures. The results showed that internal surfaces painted black provide for maximum heat sharing, and lowest block temperatures. The block temperatures were found to be very sensitive to changes in the cube external optical surface properties. A slight increase in emissivity lowered the block temperature, while a slight increase in absorptivity increased the block temperature. Heat pipes were also found to lower the temperatures of the block and immediate subsystems by providing a path of low thermal resistance to the flow of heat from the block directly to the radiator. The effect of thermal insulation was also investigated. For the two materials (rubber and plastic) that were tested, it was noticed that although insulation material does give more thermal control and predictability over a subsystem by thermally isolating it from its environment, it can cause a subsystem that has heat generation to become too hot. Recommendations were made relating to future micro satellite thermal management and control with regard to; thermal modelling techniques, acquisition of tried software, positioning of temperature sensors for optimisation of thermal data, and the verification of optical surface properties by physical measurement.
AFRIKAANSE OPSOMMING: Hierdie tesis fokus op Suid-Afrika se eerste mikro ruimte satelliet, SUNSAT, en die termiese ontwikkeling daarvan. Agtergrond teorie met betrekking tot die termiese bestuur en kontrole van die satelliet-sisteme en subsisteme word aangebied. Die missie-profiel en die samestelling van die subsisteme word ook kortliks bespreek met die klem op die fisiese strukture, moontlike wentelbane, interne hitte-opwekking, en die omgewingsverhitting. Die omgewingsverhitting op die oppervlaktes van die satelliet, veroorsaak deur direkte en weerkaatste aardlson bestraling, sowel as deur infrarooi bestraling afkomstig van die aarde, word bepaal deur die ontwikkelde rekenaarprogram ORBIT-FLUX. Hierdie program word gebruik in tandem met numeriese programme (intern ontwikkel), so weI as 'n uitgekontrakteerde program TAS (Termiese Analiese Sisteme) om SUNS AT vir twee moontlike wentelbane te modelleer. Die weerstandskapasitansie formuleringsmetode is gebruik om die numeriese programme te ontwikkel. Hierdie programme is oorspronklik gebruik om die validiteit van TAS vas te stel. Die eerste benaderde termiese model van SUNSAT se batterye was die 7 gekonsentreerdemassa model wat gefokus het op die batterye aangesien daar vermoed is dat oorverhitting van die batterye die rede is waarom SUNSAT nie sy missie voltooi het nie. 'n Numeriese program so weI as 'n gelyksoortige TAS model is ontwikkel en die resultate korreleer tot binne 3°C. 'n Gekonsentreerde-massa model van SUNSA T is ook ontwikkel, numeries en met gebruik van TAS. Die modelle is getoets en die resultate toon dat die temperature van die modelle gevoelig is vir veranderinge in interne hitte sowel as vir wissellende uitstralingsvermoe en absorpsievermoe, Die numeriese- en die TAS gekonsentreerde-massa model resultate het nie goed met mekaar korrelleer nie, moontlik weens die hoe aantal kontrole volumes wat in die TAS gekonsentreerde-massa model gebruik is. Die TAS SUNSA T 2 model is 'n verdere ontwikkeling van die gekonsentreerde-massa model. Die hoer aantal kontrole volumes en die byvoeging van solarpanele het tot gevolg gehad dat hierdie 'n meer realistiese model van SUNSA T is. Die resultate het nie goed gekorrelleer met die temperatuurdata van die werklike SUNSAT nie, moontlik weens die feit dat die solarpanele nie op die bakwerk monteer is, soos in die geval van SUNSA T nie. Nietemin het het die TAS SUNSAT 2 model gelei tot die meer gevorderde TAS SUNSAT 3 model. Hierdie termiese model het die solarpaneel montuur ingesluit en het 'n hoer aantal kontrole volumes gehad, wat 'n beter fisiese weergawe van die SUNSAT subsisteme tot gevolg gehad het. Die model is getoets vir moontlike wentelbane van SUNSAT. Die resultate het 'n hoe korrellasie getoon met die data van die werklike SUNSAT. 'n Vergelyking van die TAS SUNSAT 3 model resultate met data van SUNSAT vir Julie 1999 wys dat die SUNSAT battery temperatuur dieselfde is tot binne 8°C. Vergelyk met die resultate vir Junie 2000 was dit binne 1°C. 'n Termiese bestuurs- en kontrolestudie is gedoen op 'n eenvoudige sisteem (insluitende 'n kubieke boks en 'n interne soliede blok met hitte opwekking) om die uitwerking van die gebruik van passiewe en aktiewe termiese kontrole hardeware wat temperature reguleer, te illustreer. Die resultate toon dat interne oppervlaktes wat swart geverf is, lei tot die maksimum hitte-deling, en die laagste bloktemperature. Daar is gevind dat bloktemperature baie gevoelig is vir veranderinge in die eienskappe van die kubus se eksterne optiese oppervlaktes. 'n Effense vermedering van uitstralingsvermoe verlaag die bloktemperatuur, terwyl 'n effense vermedering van absorpsievermoe die bloktemperatuur verhoog. Daar is ook gevind dat hittepype die temperatuur van die blok en onmiddelike subsisteme verlaag deur om 'n pad van lae termiese weerstand teen die vloei van hitte vanaf die blok, direk na die verkoeler te verskaf. Die uitwerking van termiese isolasie is ook ondersoek. In die geval van die twee materiale (rubber en plastiek) wat getoets is, is daar opgemerk dat, alhoewel isolasie materiaal meer termiese beheer oor die subsisteem en voorspelbaarheid tot gevolg gehad het deurdat die subsisteem termies van die omgewing isoleer is, kan dit veroorsaak dat die subsisteem te warm word. Aanbevelings is gemaak met betrekking tot toekomstige mikro satelliet bestuur en kontrole en wel in verband met die volgende: termiese modelleringstegnieke, die aanskaffing van getoetste sagteware, die plasing van temperatuut sensors vir die beste termiese data, en die verifikasie van die eienskappe van optiese oppervlaktes deur fisiese meting.
Tilahun, Muluken. "Experimental Investigation of Hyperbolic Heat Transfer in Heterogeneous Materials." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/36509.
Full textMaster of Science
Bai, Xuemai. "Measurements of thermal properties and analysis of heat transfer in organ cryopreservation." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239211.
Full textMichener, Michael Douglas. "Measurements of thermal properties and blood perfusion using the heat flux microsensor." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/41696.
Full textMaster of Science
Giwa, Giwa Solomon Olanrewaju. "Investigation into thermal-fluid properties of hybrid ferrofluids as heat transfer fluids." Thesis, University of Pretoria, 2019. http://hdl.handle.net/2263/77818.
Full textThesis (PhD)--University of Pretoria, 2019.
Mechanical and Aeronautical Engineering
PhD
Unrestricted
Kuznetsova, O. O. "Reduction of thermal bridge effects caused by junctions between external walls and balcony slabs." Thesis, Київський національний університет технологій та дизайну, 2018. https://er.knutd.edu.ua/handle/123456789/9733.
Full textdeMartin, Brian J. "Laboratory measurements of the thermal conductivity and thermal diffusivity of methane hydrate at simulated in situ conditions." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/26216.
Full textRoth, Eric. "Nucleation and Heat Transfer in Liquid Nitrogen." PDXScholar, 1993. https://pdxscholar.library.pdx.edu/open_access_etds/1370.
Full textRückert, Marcel, Katharina Schmitz, and Hubertus Murrenhoff. "Comparison of Heat-Properties and its Implications between Standard-Oil and Bio-Oil." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200109.
Full textHe, Xiaozhou. "Thermal dissipation field and its statistical properties in turbulent Rayleigh-Bénard convection /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?NSNT%202009%20HE.
Full textIyer, Kaushik A. "Quantitative characterization of thermophysical properties in computational heat transfer." Full text open access at:, 1993. http://content.ohsu.edu/u?/etd,273.
Full textLiao, Hao-Hsiang. "Thermal and thermoelectric properties of nanostructured materials and interfaces." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/19198.
Full textPh. D.
Mueller, Jennifer Elizabeth. "Determining the Role of Porosity on the Thermal Properties of Graphite Foam." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/34110.
Full textMaster of Science
Guynn, Jerome Hamilton. "Estimation of thermal properties in a medium with conduction and radiation heat transfer." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/39292.
Full textPh. D.
Gonzalez, Ralph P. "Hollow sphere radiant thermal conductivity reduction using infrared pore opacification." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/20495.
Full textConeybeer, Robert T. "Transient thermal models for substation transmission components." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/17686.
Full textBotha, Subelia Senara. "Synthesis and characterization of nanofluids for cooling applications." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1995_1210758997.
Full textLow thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids that are required in numerous industrial sectors. Recently submicron and high aspect ratio particles (nanoparticles and nanotubes) were introduced into the heat transfer fluids to enhance the thermal conductivity of the resulting nanofluids. The aim of this project was to investigate the physico-chemical properties of nanofluids synthesized using submicron and high aspect ratio particles suspended in heat transfer fluids .
Çetinkol, Mehmet. "Structural and high pressure studies of some low and negative thermal expansion materials." Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26475.
Full textCommittee Chair: Wilkinson, Angus; Committee Member: Barefield, E. Kent; Committee Member: Snyder, Robert; Committee Member: Soper, Jake; Committee Member: Zhang, Z. John. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Houl, Yassine. "Increasing Effective Thermal Resistance of Building Envelope's Insulation Using Polyurethane Foam Incorporated with Phase Change Material." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505159/.
Full textOlsson, Martin. "Thermal Shape Factor : The impact of the building shape and thermal properties on the heating energy demand in Swedish climates." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-125076.
Full textRigas, Konstantinos. "Thermal Physical Properties of Söderberg Electrode Material." Thesis, KTH, Materialvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259191.
Full textSöderberg-elektroder används till produktionen av ferrolegeringar, koppar, nickel, platina och kalciumkarbider. De är involverade i kontinuerliga och lågkostnadsoperationer. Studien av sådana elektroder är väsentlig eftersom forskning och nya fynd kommer att ge oss viktig information om driften av sådana ugnar vilket leder till en effektivare produktion. Därför är studien av Söderberg-elektrodens materialegenskaper av stor betydelse. Det nuvarande arbetet refererar till de termiska egenskaperna hos Söderberg-elektrodpastan genom att fokusera på den termiska konduktivitetskoefficienten från rumstemperatur upp till 800°C med den TPS-metoden (Transient Plane Source) tillämpad på ett elektrodpasta-material med en mjukningspunkt vid 65°C. En annan elektrodpasta med en högre mjukningspunkt vid 90°C samt ett redan bakat material studeras även till viss del. Studien ger signifikanta resultat för värmeledningsförmågan för alla undersökta fall. Resultaten indikerar på variationer av koefficienterna gällande fasen som utvecklas under uppvärmning vid olika temperaturer. I stort sett minskar värmeledningsförmågan hos den gröna pastan med låg mjukningspunkt upp till 400°C och ökar efter bakningspunkten som finns mellan 400-500°C. Några mätningar för den gröna pastan med en högre mjukningspunkt visar samma trend. När det gäller den helt bakade elektroden verkar värmdeledningsförmågan hålla en ökande trend beroende på temeperaturökningen. På de två sistnämnda materialen kommer mer experimentellt arbete att genomföras i framtiden.
Morgan, Nathaniel Ray. "A porous medium for structural support and multiphase cooling of high-frequency conductors." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/16335.
Full textPagalthivarthi, Krishnan V. "Thermosolutal convection and related transport processes in binary alloy solidification." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/18245.
Full textBleazard, Joseph Gibson. "The thermal conductivity of aqueous electrolyte solutions and polar liquids." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/33419.
Full textBrennvall, Jon Eirik. "New techniques for measuring thermal properties and surface heat transfer applied to food freezing." Doctoral thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-979.
Full textThis thesis presents two different works. The first part introduces a thermal multimeter which measures heat capacity, thermal conductivity and density. The instrument gives continuous measurement data within a temperature range. With some exceptions this also holds for the prototype of a thermal multimeter which is built and tested. The measuring method is constant heating of one side of a slab. The slab is insulated on all other sides. After some time there will be equilibrium where there is a constant temperature difference over the slab. The thermal conductivity can be calculated from this temperature difference. The heat capacity can be calculated from how fast the temperature rises. Measurements of the slab thickness give density as function of temperature.
The second part discusses a practical method for measuring the heat transfer coefficient (α). The method is based on shell freezing of clear jelly which has the same shape as the product of interest. Transparent jelly is transparent before it freezes and white when frozen. If the sample is removed from the freezer and cut through before it is completely frozen thefreezing front is distinct and the thickness of the frozen layer can be measured. By measuring time the jelly sample was in the freezer and thicknessof the frozen layer the heat transfer coefficient can be calculated by using Plank's equation. The method is suitable for measuring local α because it can be shown that tangential heat flow can be neglected when the frozen layer is thin.
Computer simulations, automated data acquisition and data processing are a considerable part of this thesis, even though it is not obvious from the results presented. There are more lines in the data code written to obtain the results presented here then the number of lines in this thesis. The size of selected simulation results and processed data from the measurements are 6.3 GB.
Attachments can be downloaded from http://www.ub.ntnu.no/dravh/Brennvall_attachment.zip (1,33 GB)
Liu, Xianglei. "Tailoring thermal radiative properties and enhancing near-field radiative heat flux with electromagnetic metamaterials." Diss., Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/54960.
Full textKarami, Peyman. "Robust and Durable Vacuum Insulation Technology for Buildings." Doctoral thesis, KTH, Byggnadsteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176494.
Full textDagens byggnader ansvarar för omkring 40% av världens energianvändning och står också för en väsentlig del av utsläppen av växthusgaser. I Sverige kan ca 21 % av energianvändningen relateras till förluster genom klimatskalet. Miljonprogrammet är ett namn för omkring en miljon bostäder som byggdes mellan 1965 och 1974, och många av dessa byggnader har en dålig energiprestanda efter dagens mått. Huvudsyftet med denna studie har varit att utforska möjligheterna att använda vakuumisoleringspaneler (VIP:ar) i byggnader med viss fokus på tillämpning i Miljonprogrammets byggnader. Med en värmeledningsförmåga som är ca 8 - 10 gånger bättre än för traditionell isolering erbjuder VIP:arna unika möjligheter till förbättrad termisk prestanda med minimal isolerings tjocklek. Denna avhandling hade tre huvudsyften. Det första var att undersöka nya alternativ för kärnmaterial som bland annat kan reducera kostnaden vid produktion av VIP:ar. Tre nyutvecklade nanoporösa kiselpulver har testats med olika stationära och transienta metoder. En inom projektet utvecklad testbädd som kan anslutas till TPS instrument (Transient Plane Source sensor), har använts för att mäta värmeledningsförmågan hos kärnmaterial för VIP:ar, vid varierande gastryck och olika mekaniska laster. Slutsatsen blev att transienta metoder är mindre lämpliga för utföra mätningar av värmeledningsförmåga för nanoporösa kiselpulver låg densitet. Avvikelsen i resultaten är dock minimal för densiteter ovan en gräns då värmeledningen genom fasta material blir dominerande jämfört med värmeöverföring genom strålning. Det andra syftet har varit att föreslå ett nytt monteringssystem för VIP:ar som kan användas för att förbättra energieffektiviteten i byggnader som är typiska för Miljonprogrammet. Genom parametrisk analys och dynamiska simuleringar har vi kommit fram till ett förslag på ett nytt monteringssystem för VIP:ar som har utvärderats genom fullskaleförsök i klimatkammare. Resultaten från fullskaleförsöken visar att den nya tekniska lösningen förbättrar väggens U-värde med upp till 56 %. En förbättrad värmegenomgångskoefficienten för väggen i mitten av en VIP blev mellan 0.118 till 0,132 W m-2K-1 och värmeledningstalet centre-av-panel 7 mW m-1K-1 uppnåddes. Detta arbete innehåller dessutom en ny metod för att mäta köldbryggor i anslutningar med hjälp av infraröd termografi. En effektiv värmeledningsförmåga för 10.9 mW m-1K-1 uppnåddes. Resultaten tyder även på att den verkliga termiska prestandan av VIP:ar i konstruktioner är något sämre än mätvärden för paneler i laboratorium. En effektiv värmeledningsförmåga av 10.9 mW m-1K-1 ger dock väggkonstruktionen en utmärkt termisk prestanda. Det tredje syftet har varit att bedöma miljöpåverkan av en VIP-isolerad byggnad, från produktion till drift, eftersom en livscykelanalys av hela byggnader som är isolerade med vakuumisoleringspaneler inte har gjorts tidigare. Slutsatsen var att VIP:ar har en större miljöpåverkan än traditionell isolering, i alla kategorier förutom ozonnedbrytande potential. VIP:ar har en mätbar påverkan på de totala utsläppen av växthusgaser och primärenergianvändningen i byggnader när både produktion och drift beaktas. Miljöpåverkan av de använda VIP:arna är dock positiv jämfört med GWP av en standardbyggnad (en minskning med 6 %) medan primärenergianvändningen ökade med 20 %. Slutsatsen var att ytterligare användning av VIP:ar gynnas av reducerad energiförbrukning och alternativa energikällor i produktionen av nanoporösa kiselpulver medan användningen av alternativa kärnmaterial och återvinning av VIP kärnor kan hjälpa till att minska miljöpåverkan. En känslighetsanalys visade att valet av VIP:ar har en betydande inverkan på miljöpåverkan, vilket ger möjlighet att reducera den totala användningen av primärenergi i en byggnad med 12 % och utsläppen av växthusgaser kan vara minska, så mycket som 11 % när det gäller både produktion och drift under 50 år. Avslutningsvis är det möjligt att dra slutsatsen att VIP:ar är ett mycket konkurrenskraftigt alternativ för att isolera byggnader som är typiska för Miljonprogrammet. Dock krävs ytterligare undersökningar för att minimera de mätbara miljöeffekter som förvärvats i denna LCA-studie för VIP-isolerade byggnader.
QC 20151109
Simulations of heat and moisture conditions in a retrofit wall construction with Vacuum Insulation Panels
Textural and thermal conductivity properties of a low density mesoporous silica material
A study of the thermal conductivity of granular silica materials for VIPs at different levels of gaseous pressure and external loads
Evaluation of the thermal conductivity of a new nanoporous silica material for VIPs – trends of thermal conductivity versus density
A comparative study of the environmental impact of Swedish residential buildings with vacuum insulation panels
ETICS with VIPs for improving buildings from the Swedish million unit program “Miljonprogrammet”
Min, Kyung-Eun. "A Study of Thermal Energy Storage of Phase Change Materials: Thermophysical Properties and Numerical Simulations." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/4835.
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