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Fluid flow analysis in the open cylindrical container with the free surface vortex
Illík, Jakub ; Klas, Roman (referee) ; Štigler, Jaroslav (advisor)
This master's thesis analyses fluid flow in an open cylindrical tank with vortex using numerical simulation. The theoretical part introduces a set of equations governing fluid flow and relations used to describe vortex motion. A general overview of terms used in computational fluid dynamics is presented. The experimental section consists of three parts. The vortex modelling is performed using ANSYS Fluent software. Data are consequently analysed within ANSYS CFD-Post software tool. Special focus is put on the vortex shape that is fitted with a curve corresponding to a probability density function of the Cauchy distribution. Results are then plotted in MATLAB software.
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Manufacturing inaccuracies influence on an appearence of the additional moment on a sailboat rudder
Kazda, Adam ; Fic, Miloslav (referee) ; Štigler, Jaroslav (advisor)
This Master’s thesis is dedicated to a generation of an additional torque, which can occur due to the inaccuracy of the manufacturing. This issue is inspired by a real case from 2013. In this work CFD modeling is used to investigate three different sources of the additional torque: misalignment of the rudder, deviation of the propeller shaft and asymmetry of the rudder. A simplified 2D simulation is done for all three cases. This simulation is more suitable for a jet powered boat. Therefore the asymmetry of the rudder is investigated also in a 3D case, where the rotational component of the flow behind the propeller is included.
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Feasibility study pumped storage hydropower plant in a particular locality
Vaněk, Michal ; Štigler, Jaroslav (referee) ; Hudec, Martin (advisor)
Electric energy storage represents an area, which needs to be further developed in order to accommodate more installed capacity of wind and solar power plants in the electric grids. Pumped hydro energy storage still remains ahead of other storage technologies in terms of achievable storage capacity. However, environment protection which is one of the obstacles for further PHES development in Europe causes significant reduction of suitable sites. It is therefore useful to examine also those sites, which seem to be less favourable for PHES at the first glance. This thesis deals with a feasibility study of a PHES on place of a former graphite surface mine. The thesis includes computation of basic capacities, choice of a suitable machine arrangement and introduction into PHES feasibility issues in electric grids. Two possible solutions of a smaller PHES that differ in their capacities were suggested based on available materials about the site as well as on available materials from Francis pump turbine model research. In case of both solutions a binary machine set is used and the available capacities are in small tens of megawatts. However, there is a wide head variation at the site, which causes significant power variation. Concerning the feasibility of the PHES, it is very uncertain that the participation in the day-ahead electricity market, would provide enough revenue to cover operation and capital costs. A following economic analysis investigating the capital costs of this particular PHES would be beneficial, as well as more detailed design of the reservoirs.
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Analogies in fluid dynamics: vortex as a black hole
Staňo, Šimon ; Štigler, Jaroslav (referee) ; Illík, Jakub (advisor)
This bachelor thesis discusses the various analogous connections of fluid dynamics with the fields of electricity, electromagnetism, quantum mechanics and gravity. Par- ticular attention has been focused on a certain similarity between rotating black holes and the draining bathtub vortex. At first sight different phenomena that can be ex- plored by simulating known phenomena. The behaviour around real black holes can, with some simplification, be studied within the hydraulic laboratory. The pioneer of this idea is W. G. Unruh, whose work was followed up and continued with research by Silke Weinfurtner. Her research served as the inspiration for the exploration of this field in this bachelor thesis. It is possible to visualize the event horizon of a black hole or the boundaries of the ergosphere, it is also possible to observe more complex phenomena such as superradiance, backreaction or ringdown. The analogy is not completely precise, but it allows a very complex system to be studied with a simple experiment and can lead to a better understanding of these phenomena. A simple experimental setup was created in the laboratory of Victor Kaplan’s Department of Fluid Engineering.
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Design of cleaning robot for industrial air conditioning based on dry ice blasting technology
Novotný, Viktor ; Haltof, Vladimír (referee) ; Štigler, Jaroslav (advisor)
The aim of this work is to design cleaning robot for industrial air conditioning based on dry ice blasting technology, which will be able to clean different types and sizes of pipes. The versatility of the robot was achieved by the adjustability of the different parts and the possibility to add additional components for vertical movement. The possibility of inserting the robot into pipes with entrance holes of different sizes is solved by a modular system. Ease of cleaning was achieved by covering the body. Focus was also placed on the ergonomics of the robot.
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Irrigation systems in the past and nowadays
Slinčák, Andrej ; Fialová, Simona (referee) ; Štigler, Jaroslav (advisor)
The bachelor thesis is focused on general overview of problematics of irrigation systems for large agricultural fields, as well as micro-rrigations for gardens. It includes pros and cons of every system and elucidate appropriate aplication of irrigation to certain conditions. Thesis describes elements of irrigation system and conditions for its proper functioning. In the first part is described brief history of irrigation systems, afterwards its division by use and the way they work. I also added short introduction to gravitation (surface) irrigation. It is these techniques, which are used in developing countries with sufficient water resources. The second part is a description of a specific irrigation system from my neighborhood. I have chosen our automatic irrigation system from firm TORO, which is used for lawn irrigation.
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Microplastics removing from water
Ermis, Martin ; Himr, Daniel (referee) ; Štigler, Jaroslav (advisor)
This thesis deals with the occurrence of microplastics in water, the reasons for their potential elimination, and the possibilities leading to that. More specifically, it focuses on flotation as a process for removing microplastics from water. Flotation is further described from a theoretical point of view and its mathematical model is developed. The wettability of selected polymers is measured. The experiment performed to determine the efficiency of flotation as a process of treating water from microplastics is described. This efficiency is further compared to measured wettability.
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