The aim of the diploma thesis is the simulation of different types of air conditioners using the CFD methods. The main goal of this thesis is to design the most suitable type of air conditioning in the consideration room, due to the air flow rate in the residental area. The conclusion of the work is to devote the design of air conditioning system with the application of selected type of air conditioning based on the results of CFD simulations.

The main objective of this thesis is to propose and evaluate two variants of HVAC systems for clean rooms. The proposed system is pressurized. As part of the experimental section in which the data obtained are evaluated - humidity and air temperature.

The Middle and Upper Atmosphere Model (MUAM) was used for the period from 1979 to 2015 and for January and July to analyze the interannual and longterm development of the horizontal wind and temperature in the middle atmosphere. Above the troposphere, for each season a long-term temperature decrease was observed, with maxima in the polar stratosphere in winter. In the zonal wind, a weakening and slight northward displacement of the mesospheric westerly wind could be observed in the respective winter hemisphere. On the southern hemisphere in January there was a slight weakening of the wind jets, while in the northern hemisphere a slight increase could be observed in July. For the meridional wind, especially for the mesospheric branch of the meridional wind jet, the southerly wind was intensified in January, while the northerly wind weakened particularly in the southern hemisphere in July. Possible reasons for the long-term trends are discussed. / Mit dem Modell für die mittlere und obere Atmosphäre MUAM wurden Berechnungen über den Zeitraum von 1979 bis 2015 für Januar und Juli durchgeführt, um die Entwicklung des Zonal- und Meridionalwindes sowie der Temperatur zu analysieren. Dabei zeigte sich ganzjährig ein Temperaturrückgang oberhalb der Troposphäre, mit einem Maximum in der polaren Stratosphäre während des Winters. Beim Zonalwind ließ sich in der jeweiligen Winterhemisphäre eine Abschwächung und leichte Nordverlagerung des mesosphärischen Westwindjets beobachten. Auf der Südhemisphäre im Januar kam es zu einer leichten Abschwächung der Starkwindbänder, während im Juli auf der Nordhemisphäre eine leichte Verstärkung festgestellt werden konnte. Für den Meridionalwind, insbesondere für den meridionalen mesosphärischen Windjet zeigte sich im Januar eine Intensivierung des Südwindes, während sich der Nordwind im Juli besonders auf der Südhemisphäre abschwächte. Gründe für diese Trends werden diskutiert.

The feedback between clouds and sea ice got more importance in the last years, because of the declining Arctic sea ice extent. Previous observations show the formation of low clouds over newly formed open water. These low clouds are very important for the Arctic Energy Budget, because they warm the surface. This leads to increasing temperatures and stronger sea ice loss. To assess the relationship between sea ice cover and cloudiness, satellite observations by DARDAR were compared with both global climate reanalyses ERA–Interim and MACC. The analysis focuses on 2007 – 2010 and the relationship between different parameters from the different datasets. It is found that the reanalyses only poorly approximate the cloud cover in the Arctic. Consequently no strong correlation was found for the time period 2007 – 2010. / Das Wolken–Albedo–Feedback in der Arktis gewann in den letzten Jahren immer mehr an Bedeutung aufgrund des Rückganges der Meereisfläche. Vorhergehende Arbeiten zeigten die Bildung von tiefer Bewölkung über kürzlich aufgebrochenen Meereisstellen. Diese tiefen Wolken sind sehr wichtig für das arktische Energiebudget, wegen des Erwärmens der Oberfläche. Daraus folgt ein Anstieg in der bodennahen Temperatur und ein verstärkter Rückgang des Meereises. Um den Einfluss der Meereiskonzentration auf die Wolkenbildung zu untersuchen, werden in dieser Arbeit Satellitendaten von DARDAR mit den beiden globalen Klimareanalysen Era–interim und MACC verglichen. Analysiert werden Daten aus den Jahren 2007 bis 2010 und für verschiedene Oberflächenbedingungen werden Korrelationen der einzelnen Datensätze erstellt. Es hat sich gezeigt, dass die Darstellung der Wolkenbedeckung in der Arktis durch die Reanalyse Daten nicht geeignet ist. Aus diesem Grund wurden keine signifikanten Korrelationen in der Zeitspanne von 2007 bis 2010 gefunden.

In dieser Arbeit wird über Klimamessungen berichtet, die beide Autoren in den achtziger Jahren im Raum Leipzig durchgeführt haben. Damit wird ein erster Versuch der Darstellung stadtklimatologischer Differenzierungen in Leipzig unternommen. Anhand der mittleren Lufttemperaturen läßt sich die städtische Wärmeinsel nachweisen. Darüber hinaus wird eine kleinräurnige Niederschlagsverteilung von Leipzig angegeben.

Der Einfluss der direkten Sonnenstrahlung kann trotz Strahlungsschutz und Ventilation zu deutlichen Fehlern bei der Bestimmung der Lufttemperatur führen. Zur Verringerung des Strahlungsfehlers in einer ventilierten Hütte wurde um die Temperatur- und Feuchtesensoren doppelte Strahlungsschutzrohre angebracht. Vergleichsexperimente haben gezeigt, dass damit ein wesentlich besserer Schutz vor der direkten Sonnenstrahlung erreicht wurde. / The influence of direct solar radiation and – despite a radiation shelter and sufficient ventilation – may cause an overestimation of the air temperature. To reduce the influence of the direct radiation, a double radiation protection tube was mounted around the temperature sensor. A cross validation has demonstrated, that consequently a much better radiation protection was realized.

Das Jahr 1816 ist in die Klimatologie als das 'Jahr ohne Sommer' eingegangen. Der 1815 erfolgte Ausbruch des Vulkans Tambora auf der indonesischen Insel Sumbawa führte im darauffolgenden Jahr in vielen Teilen der Welt zu katastrophalen Missernten. Während in Nordamerika daran besonders die außerordentlich tiefen Sommertemperaturen Schuld waren, scheinen in Europa dafür sowohl die unter dem Durchschnitt liegenden Temperaturen wie auch die überdurchschnittlichen Regenmengen verantwortlich zu sein. Zeitgenössische Berichte wie auch Niederschlags- und Pegelaufzeichnungen aus verschiedenen Teilen Europas belegen eine besonders hohe Niederschlagstätigkeit im 'Erntemonat' Juli des Jahres 1816 und eine hohe Wasserführung der großen europäischen Ströme in den Jahren 1816 und 1817. / The year 1816 is known in climatology as the 'Year without Summer'. The eruption of the Tambora volcano on the Indonesian island Sumbawa in 1815 led to catastrophic crop failures over many parts of the world in the following year. Whereas in North America those failures originated from extraordinarily low summer temperatures, causes in Europe seem to have been below-normal temperatures as well as above-normal rainfall. Contemporary reports and also precipitation and river gauge measurements from different parts of Europe document enhanced precipitation in July 1816 ('Erntemonat') and high discharges of large European rivers in years 1816 and 1817.

Conventional micro-meteorological measuring methods are not particularly suitable for the investigation of the energy exchange under heterogeneous surface conditions. To consider the influence of the different surface properties, area-covered and spatially averaged meteorological measurements in combination with highly resolved simulations are necessary. In this context, the method of acoustic travel time tomography is introduced to provide information about the horizontal temperature and wind field. Within a field experiment (STINHO-1; Melpitz 2001) the tomographic system and conventional meteorological equipment were utilised inside the investigation area with an extension of several hundred meters (300 x 700 m2), which was arranged over areas with different surface properties: grassland and bare soil. The results of the field experiment show that differences between the measuring systems (insitu and remote sensing) exist and the heterogeneity of the underlying surface is visible in the near surface temperature and wind field at a scale, which can be resolved with highly resolved numerical models. Depending on the incoming solar radiation and the local advection regional distinctions in the air temperature and wind field as well as in the vertical sensible heat fluxes were observed. The investigations demonstrate that the sensitivity of the Acoustic Tomography is sufficient to verify gradients in the meteorological fields even when the horizontal differences are small. / Zur Untersuchung des Energieaustausches über heterogenem Gelände sind konventionelle mikro-meteorologische Messungen und Modellvorstellungen allein nicht ausreichend. Um den Einfluss unterschiedlicher Oberflächen besser berücksichtigen zu können, sind flächendeckende und räumlich mittelnde meteorologische Messungen kombiniert mit hoch aufgelösten numerischen Simulationen notwendig.In diesem Kontext wird die Methode der Akustischen Laufzeitomographie vorgestellt, mit der horizontale Wind- und Temperaturfelder in geeigneter Weise bereitgestellt werden können. Im Rahmen eines Feldexperimentes (STINHO-1; Melpitz 2001) wurde das tomographische System zusammen mit konventionellen meteorologischen Geräten in einem Untersuchungsgebiet mit einer Ausdehnung von mehreren hundert Metern (300 x 700 m2) über unterschiedlichen Oberflächen (Wiese und gepflügter Acker) eingesetzt. Die Ergebnisse des Feldexperimentes zeigen, dass Unterschiede zwischen den einzelnen Messverfahren existierten und die Heterogenität der Unterlage in den oberflächennahen Temperatur- und Windfeldern auf einer Skala sichtbar ist, die mit kleinskaligen numerischen Modellen aufgelöst werden kann. Die vorgestellten Untersuchungen demonstrieren, dass die Sensitivität der Akustischen Tomographie hinreichend ist, um Gradienten meteorologischer Felder auch bei geringeren horizontalen Unterschieden nachzuweisen.

The study of the traffic noise as an environmental impact, the search for solutions to this problem, and the development of noise measurement methodologies that help in the search of these solutions, is now a fundamental responsibility for the transportation industry.   So, in line with this responsibility, consistent work was made with focus on tire/pavement noise measured over different pavement surfaces, and under different environmental conditions, and different speeds. In a parallel way, work was conducted for the development, improvement, and practical use of the On- Board Sound Intensity (OBSI) methodology for tire/pavement noise measurements.   The first part of this thesis shows the results of field experimentation about the influence of external factors like air temperature and vehicle speed over the tire/pavement noise measured with the OBSI methodology. Temperatures from 40 to 90"F were targeted, and speeds from 35 mph to 60 mph (range in which tire/pavement noise becomes predominant for the overall vehicle noise) were tested. For this work a series of seasonal field tests were conducted on a primary road in Virginia over various months.  The results were analyzed to quantify the variation of tire/pavement noise with respect to the air temperature and test speed, and therefore to find correction factors for this variables in order to normalize the data taken under different conditions. In the second part of this thesis, the study of tire/pavement noise over different surfaces and measured over a timeframe of three seasons is presented. This part presents results about noise reduction potentials of two proposed "quiet" concrete technologies and 3 proposed "quiet" asphalt surfaces when compared with one another, and with control sections. Also the second part of the thesis includes results about the susceptibility of the proposed surfaces to external factors such as: aging (three seasons involved), air temperature differentials and winter maintenance. In general, the findings show trends that tire/pavement noise slightly decreases as air temperature increases. A gradient of approximately -0.05 dBA/"F was found. It was found as well that tire/pavement noise increases an average of 2.5 dBA for every 10 mph of increased speed.   The statistical analysis results for the second part of the thesis shows that all proposed concrete surfaces and asphalt surfaces present benefits in terms of noise reduction, For the asphalt surfaces, it was found that more voids in the surface helps to absorb the noise. In addition, the rubber modified mixes show an improved noise reduction potential. Air temperature normalization was performed an a statistical analysis was conducted; it was found that air temperature has a significant influence in the noise measurements especially for the first months of use. Finally it was found that there is a slightly increase in noise over time after the first months of use. / Master of Science

Energy calculations are used for many purposes, for example during the design andconstruction phase to comply with Boverket’s building regulations, energy declarations or toachieve energy saving in a building. A main problem in the design process of a new building,is to accurately predict the energy performance. The energy calculations require data fromdifferent interacting components, which have been shown to be challenging to measure. Thisproblem arises in particularly for complex buildings, notably office buildings. Due to the lackof detailed energy models and analyses of the differences between the model and reality foroffice buildings in Sweden, this report aims to answer the question: What are the causes ofdeviations between the models and the measurements of energy usage and indoor airtemperature for the studied office building? The office building Sthlm New 04 was modeledas a whole-building within IDA ICE and the simulated data was compared with measureddata from 2021 that was provided by Skanska Fastigheter.During the design of the model, the simulation model was fed with external source files (withmeasured data) to make the model operate at the same time as the real system. Since therewas no logged occupancy data for this office building, it was assumed that occupancy wasdistributed equally in all office zones. The model has a detailed HVAC system to make themodel as accurate as possible.The result showed overall a good agreement with the measured data, especially for thesimulated district heating and cooling. However, a closer look revealed that there were somedifferences that the model did not account for. The building’s three Air-handling units alsoshowed a good agreement with an average of -0.3 °C, -0.2 °C and +0.2 °C. The resultshighlight several problems with modeling and measured data. Under the influence ofassumptions and hard to define input data, there may be misinterpretation by the modeler.Other reasons could be sensor errors or manufacturing errors by most of the errors could becorrected by a more detailed occupancy in the model. However, this study has shown thatthe detailed model can be used for a fair comparison between the simulated model and thereal building, although there may be some discrepancies. Undoubtedly, it is difficult to createa model that exactly matches the real building, but this model is a good representation thatcan be used for future research such as digital twin.