Mesogranular structure in a hydrodynamical simulation

We analyse mesogranular flow patterns in a three-dimensional hydrodynamical simulation of solar surface convection in order to determine its characteristics. We calculate divergence maps from horizontal velocities obtained with the Local Correlation Tracking (LCT) method. Mesogranules are identified as patches of positive velocity divergence. We track the mesogranules to obtain their size and lifetime distributions. We vary the analysis parameters to verify if the pattern has characteristic scales. The characteristics of the resulting flow patterns depend on the averaging time and length used in the analysis. We conclude that the mesogranular patterns do not exhibit intrinsic length and time scales

Evaluation of Gas Flow at the Proposed Shapes of Scintillation Detector Aperture Sieves

V práci bude nejprve stručně popsána problematika elektronové mikroskopie a fyzikální model proudění tekutiny. Následně bude v systému SolidWorks, pro vytváření 3D objemových modelů, vytvořen zjednodušený trojrozměrný model scintilačního detektoru. Na tomto 3D modelu bude pomocí systému SolidWorks Flow Simulation metodou konečných objemů analyzováno a porovnáváno proudění plynu za clonkou. Tato clonka bude analyzována v několika variantách: clonka s otvorem 0.6 mm a clonky s otvory v podobě sítí. Výsledky analýz budou porovnány vzhledem k uvedeným požadavkům. Z analyzovaných části budou vhodné tvary následně prakticky proměřeny.This work describes briefly electron microscopy issue and physical model of fluid flow. Then the simplified three-dimensional model of scintillation detector will be created in SolidWorks system for 3D cubical models. The gas flow behind the screening in this 3D model will be analyzed and compared by method of finite cube method in SolidWorks Flow Simulation system. This screening will be analyzed in several variants: the screening with 0.6 mm opening and the screening with net-like openings. The results of analyses will be compared according to the requirements. The appropriate shapes from the analyzed parts will be practically measured.

Development Tool for Design of Vehicle Battery Management System

Bakalářská práce se zabývá návrhem a sestavením testovacího HiLu pro vývoj battery management systému elektromobilu. Úvodní část je věnována teoretickému rozboru trakční baterie a její monitorování. Jsou zde popsány konkrétní aplikace a využití v elektromobilech. V druhé části je za pomocí vytipovaných komponent navržen a sestaven testovací HiL, pomocí vývojového prostředí CANoe a programovacího jazyku C# je také zprovozněn. Poslední část se zabývá navrženou a správně namodelovanou konkrétní aplikací, která může být využita pro školní účely jako laboratorní úloha.The bachelor thesis contains the design and compilation of a test HiL for the development of an electric vehicle battery management system. The introductory part is devoted to the theoretical analysis of the traction battery and its monitoring. Specific applications and uses in electric vehicles are described. In the second part, a test HiL is designed and assembled with the help of selected components which is put into operation using the CANoe development environment and the C # programming language. The last part deals with a designed and correctly modeled specific application which can be used for school purposes as a laboratory task.430 - Katedra elektronikyvýborn

Analysis of the supersonic flow of gas in the differentially pumped chamber EREM

V práci bude nejprve stručně popsána problematika elektronové mikroskopie a fyzikální model proudění tekutiny. Následně předložená diplomová práce se bude zabývat analýzou a vyhodnocením vlivu nadzvukového proudění na tlak a hustotu v dráze primárního svazku elektronů v komoře diferenciálního čerpání. Jako nástroje pro analýzu, vyhodnocení a prozkoumání dané problematiky budou použity systémy CAD a CAE (Computer Aided Engineering - počítačová podpora inženýrských prací). Současně bude vytvořena metodika výpočtu uplatnitelná pro nadzvukové proudění v oblasti nízkých tlaku v systému ANSYS CFX.This work describes briefly electron microscopy issue and physical model of fluid flow. Then presented diploma thesis will be describing analysis and evaluation of the impact of supersonic flow on the pressure and density in the path of the primary electron beam in the differential pumping chamber. For analysis, evaluation and examination of the issue will be used CAD and CAE (Computer Aided Engineering) programs. At the same time it will be developed a methodology of calculation applicable to supersonic flow in the low pressure system at ANSYS CFX.

Development of a Communication Gateway for Controlling the Demonstration Car Model

Práce se zabývá návrhem a realizací komunikační brány pro bezdrátové ovládání demonstračního modelu automobilu. Návrh komunikační brány zahrnuje jak HW část tak i SW. Práce se také věnuje návrhu simulace zjednodušeného automobilového systému ve vývojovém prostředí Vector CANoe, která zahrnuje tvorbu databázového souboru s definicí CAN zpráv a signálů potřebných pro ovládání demonstračního modelu.The thesis is focused on the design and implementation of a communication gateway for wireless control of a demonstration car model. The design of the communication gateway includes both the HW part and the SW part. The thesis also includes the design of a simulation of a simplified automotive system in the Vector CANoe development environment, which includes the creation of a database file with the definition of CAN messages and signals needed to control the demonstration model.430 - Katedra aplikované elektronikyvýborn

Individual Professional Practice in the Company

V této práci je obsaženo shrnutí mého působení ve firmě ABB s.r.o, do které jsem nastoupil z důvodu absolvování individuální odborné praxe. Zmíněná práce obsahuje mé seznámení s programy, které jsem následně využil pro práci na ať už interních, nebo externích projektech, které mi byly během mé praxe zadány. Projekty, na kterých jsem působil v rámci mé odborné praxe se týkaly především úpravy. Nebo tvorbou rozvaděčů. Taktéž tato činnost byla doprovázena tvorbou technické dokumentace. Cílem mé bakalářské praxe je vzdělat se v oblasti praktického využití projektování a osvojit si práci ve firmě působící v oblasti elektrotechniky a automatizace.This work contains a summary of my functioning at ABB s.r.o, where I joined to fulfill the requirement of individual professional practice. The mentioned work encompasses my familiarization with programs that I subsequently utilized for tasks on both internal and external projects assigned to me during my work. The projects I participated in during my professional practice primarily focused on modification or creation of switchboards. Additionally, this activity was accompanied by the creation of technical documentation. The aim of my bachelor's practice is to gain education in the practical application of designing and to acquire skills for working in a company operating in the field of electrical engineering and automation.410 - Katedra elektroenergetikyvýborn

Assessment of a mature hydrocarbon field in SE Czech Republic for a CO2 storage pilot

Preparation and execution of a CO2 storage pilot project is one of the first logical steps in the effort to kick-start CCS in the region of Central & Eastern Europe, utilizing onshore geological structures for permanent CO2 storage. The main aims of this activity are to test the suitability of local geological structures and demonstrate the feasibility and safety of the technology to local stakeholders. The Czech-Norwegian CO2-SPICER project is an example of such developments. The target structure of CO2-SPICER – Zar−3 – is a hydrocarbon field situated in an erosional relict of fractured carbonates of Jurassic age on the SE slopes of the Bohemian Massif, covered by Paleogene deposits and Carpathian flysch nappes. The first stage of site assessment has been completed, and the article provides an overview of its results. Construction of a 3D geological model of the storage complex was the first important step on the route, preparing input for subsequent reservoir simulations of the field history and planned CO2 injection. Reservoir assessment is also focusing on specific features of the fractured-vuggy reservoir and accounting for the effects associated with CO2 injection, including geochemistry and geomechanics. Geochemical studies focus on fluid-rock interactions, and geomechanical ones on formation integrity and fracture mechanics under reservoir pressure build-up and cooling of the formation by injected CO2. Risk assessment is another component of the project, aiming at identifying potential leakage pathways and assessing consequences for the area of interest. Preparatory work for the site monitoring plan includes applicability analysis of various monitoring methods, supported by execution of baseline monitoring of selected phenomena, in particular composition of soil gas, natural and induced seismicity and properties of shallow groundwater. The project also includes evaluation of advanced reservoir containment monitoring technologies including time-lapse pressure transient analysis. While the key actions are directed towards the piloting activities, the project also looks beyond to full-field implementation and potential to establish a regional CCS cluster.acceptedVersio

Tracking magnetic bright point motions through the solar atmosphere

High-cadence, multiwavelength observations and simulations are employed for the analysis of solar photospheric magnetic bright points (MBPs) in the quiet Sun. The observations were obtained with the Rapid Oscillations in the Solar Atmosphere (ROSA) imager and the Interferometric Bidimensional Spectrometer at the Dunn Solar Telescope. Our analysis reveals that photospheric MBPs have an average transverse velocity of approximately 1 km s−1, whereas their chromospheric counterparts have a slightly higher average velocity of 1.4 km s−1. Additionally, chromospheric MBPs were found to be around 63 per cent larger than the equivalent photospheric MBPs. These velocity values were compared with the output of numerical simulations generated using the MURAM code. The simulated results were similar, but slightly elevated, when compared to the observed data. An average velocity of 1.3 km s−1 was found in the simulated G-band images and an average of 1.8 km s−1 seen in the velocity domain at a height of 500 km above the continuum formation layer. Delays in the change of velocities were also analysed. Average delays of ∼4 s between layers of the simulated data set were established and values of ∼29 s observed between G-band and Ca II K ROSA observations. The delays in the simulations are likely to be the result of oblique granular shock waves, whereas those found in the observations are possibly the result of a semi-rigid flux tube

Inquiry into the temperature changes of rock massif used in energy production in relation to season

This research was undertaken to perform and evaluate the temperature measurement in the ground utilized as an energy source with the goal to determine whether significant temperature variations occur in the subsurface during the heating season. The research infrastructure situated on our University campus was used to assess any variations. The observations were made at the so called "Small Research Polygon " that consists of 8 monitoring boreholes (Borehole Heat Exchangers) situated around a borehole used as an energy source. During the heating season, a series of monthly measurements are made in the monitoring boreholes using a distributed temperature system (DTS). Raman back-scattered light is analysed using Optical Frequency Time Domain Reflectometry (OTDR). Our results indicate that no noticeable changes in temperature occur during the heating season. We have observed an influence of long-term variations of the atmospheric conditions up to the depth of a conventional BHE (& AP;100 m). The resulting uncertainty in related design input parameters (ground thermal conductivity) was evaluated by using a heat production simulation. Production data during one heating season at our research facilities were evaluated against the design of the system. It is possible to construct smaller geothermal installations with appropriate BHE design that will have a minimal impact on the temperature of the surrounding rock mass and the system performance.Web of Science2121art. no. 702

Comparisons of Supergranule Characteristics During the Solar Minima of Cycles 22/23 and 23/24

Supergranulation is a component of solar convection that manifests itself on the photosphere as a cellular network of around 35 Mm across, with a turnover lifetime of 1-2 days. It is strongly linked to the structure of the magnetic field. The horizontal, divergent flows within supergranule cells carry local field lines to the cell boundaries, while the rotational properties of supergranule upflows may contribute to the restoration of the poloidal field as part of the dynamo mechanism that controls the solar cycle. The solar minimum at the transition from cycle 23 to 24 was notable for its low level of activity and its extended length. It is of interest to study whether the convective phenomena that influences the solar magnetic field during this time differed in character to periods of previous minima. This study investigates three characteristics (velocity components, sizes and lifetimes) of solar supergranulation. Comparisons of these characteristics are made between the minima of cycles 22/23 and 23/24 using MDI Doppler data from 1996 and 2008, respectively. It is found that whereas the lifetimes are equal during both epochs (around 18 h), the sizes are larger in 1996 (35.9 +/- 0.3 Mm) than in 2008 (35.0 +/- 0.3 Mm), while the dominant horizontal velocity flows are weaker (139 +/- 1 m/s in 1996; 141 +/- 1 m/s in 2008). Although numerical differences are seen, they are not conclusive proof of the most recent minimum being inherently unusual.Comment: 22 pages, 5 figures. Solar Physics, in pres