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Optimization of the cockpit ventilation system of a small transport aircraft
Vícena, Ondřej ; Charvát, Pavel (referee) ; Fišer, Jan (advisor)
This thesis deals with the optimization of the cockpit ventilation system of a small transport aircraft. The current system does not allow the ECS system to function without activating the main engines, which limits its effectiveness in ground operations. The theoretical part provides a basic theoretical framework for understanding and evaluating the thermal comfort in the cockpit, including heat transfer modes, cabin microclimate during different operating modes, and the definition of fundamental concepts related to ECS in pressurized and non-pressurized cabins. The experimental part focuses on the extension of the system with a suitable electric motor fan to provide cabin air supply even during ground operations at the airport. It includes testing the thermal effect of the supplied untreated air on the human body using a thermal manikin and a cabin simulator. In addition, heat removal from the body surface and subjective thermal sensation at different airflows and outlet routing were investigated for ambient temperature.
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Sleep quality depending on room environment
Veličková, Kateřina ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
The aim of this diploma thesis was to determine the thermal resistance of selected sleep assemblies (clothing, mattress, blanket, pillow) using measurements with a thermal manikin and subsequently to determine the appropriate ambient temperatures at which a balanced thermal equilibrium between the sleeping person and their environment would be maintained. Four different assemblies were selected for measurement purposes, differing in the type of blanket used (summer blanket, quilt, cover, and no blanket). The influence of the thermal manikin's position on the measured value was also investigated. It was proven that the influence of position on the overall thermal resistance is negligible, with measured values ranging from 1.12 clo (assembly without a blanket in the side position) to 2.05 clo (assembly with a summer blanket in the back position). Subsequently, appropriate ambient temperatures were determined using the PMV model, which ranged from 24.4 °C to 28.6 °C. The two-node model proved to be insufficiently sensitive for the addressed issue, and the heat flux maps derived from the equivalent temperature model were not calibrated for sleep but for mild activity while seated. Nevertheless, they provided interesting information about the perception of thermal comfort in different parts of the body.
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Measurement of indoor environment by means of thermal manikin
Ševeček, Jan ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
This dissertation deals with the measurement of the internal environment through thermal manikin Newton, especially in terms of thermal comfort. Measurements were performed in a typical office environment and cabins of small transport aircraft. The course of events and the time constants for the measurement in the office was given by real flow in the office when the sequences of events were unfolded from the usual transactions carried out during the day. In contrast, the second measurement, which took place in the model of small transport aircraft, the course of events and time constants, was performed exactly according to predetermined plan. The other parts of the thesis describe how to calibrate the manikin and then generate a diagram comfort zones. Following are compared individual test cases and events using the diagram comfort zones. Finally, individual test cases and events are compared using the diagram comfort zones and medics according to ISO 14505-2.
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Determination of heat transfer coefficients from the surface of the thermal manikin
Fojtlín, Miloš ; Tuhovčák, Ján (referee) ; Fišer, Jan (advisor)
This thesis deals with an experimental determination of heat transfer coefficients from the surface of the thermal manikin. The main focus of the work lies on separating radiative and convective heat fluxes from the surface of the thermal manikin. Both nude and clothed, standing and seated postures were investigated respectively. The tests were conducted in a constant air temperature (cca 24°C) and a constant wind speed (cca 0,05 m.s-1) environment. The major part of the radiative heat flux was eliminated by a low emissivity coating applied to the surface of the nude thermal manikin, and in the case of clothed manikin by a low emissivity two-piece dress. Favorable results were achieved only in the case of the nude manikin measurements. The measurements were performed across 34 zones that logically represent parts of a human body. Experimental work confirms theoretical expectations in the means of a heat transfer. In addition, the results of this work were compared to results of a similar experimental work. The outcomes of this thesis provide essential information in order to create detailed computational models of a thermal environment. Such models require anatomically specific, separate values of convective and radiative heat transfer coefficients.
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Drivers clothing thermal resistance database for iHVAC system
Hrubanová, Kristýna ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
This diploma thesis is focused on measurement of thermal properties of clothes by thermal manikin and on application of results for prediction of thermal comfort in system iHVAC. First part of thesis is dedicated to research with relation to this topic and to definitions of main computational equations necessary for experimental measurement. The choise of method for measurement based on available standards is an important part of this thesis. The main focus of thesis lies on measuring 5 combinations of clothes at different calibration temperatures and same temperature of manikin surface. Then data are examined and also the analysis of uncertaities and repeatability is maked. According to assupmtion , the independence of value of heat transfer coefficient to ambient temperature is comfirmed and calculated heat resistance of every single clothes is compared to existing wardrobe for system iHVAC. The outcome of this thesis is specificied and completed virtual wardrobe which serves to prediction of thermal comfort in car.
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Determination of thermal properties of gloves by means of thermal manikin
Pidrová, Kateřina ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
This diploma thesis is focused on determination of thermal properties of gloves by means of thermal manikin. The background research with relation to this topic together with derivation of the computational equations used for the following measurement are presented in the first part. The most significant part of this work is suggestion of procedure for measuring the heat resistance of gloves with thermal manikin based on procedure from ČSN EN 511. This methodics was verificated with 5 pairs of gloves together with analysing the uncertainties and testing the repeatability of this measurement. This work also contains the outline for all of the measured pairs with posibilities of their usage in specific situations and surrounding air temperatures. At the end of this work is mentioned brief summary of achieved results.
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Thermal comfort and its estimation
Žáková, Monika ; Vondra, Vlastimil (referee) ; Nováková, Zuzana (advisor)
This paper summarizes the problems of human thermoregulation and its measurement, with a focus on the method of indirect calorimetry in resting conditions at different ambient temperatures and during physical activity. It also introduces the issue of human thermal comfort and the methodology of its monitoring using thermal manikin. It describes PowerCube Ergo (Ganshorn, Germany) and Cardiovit AT-104 (Schiller, Switzerland), the diagnostic devices used to spiro-ergometry measurements. It introduces the options to export data. The work proposes the protocol for measuring the thermoregulation of the small group of volunteers, which is realized by the practical part. According to the same protocol is monitored thermal comfort of the thermal manikin. In MATLAB is created the application, allowing clear analysis of measurement records. The data are evaluated and discussed.
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Ventilated protective clothing for healthcare staff in contaminated environments
Štenclová, Kristýna ; Kopečková, Barbora (referee) ; Fišer, Jan (advisor)
Focus of the masters thesis is experimental verification of cooling effect of ambient air stream directed under a protective clothing of a human. The first part is a review of literature encompassing concepts related to thermal comfort and heat transfer. Possibilities of cooling a human who is moving in high ambient temperature environment are introduced in this part. The second part is focused on hypotheses devised and experiments performed. The last part is focused on results of the experiments and their comparison with an experiment described in literature.
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