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Proposal of shaft alignment method for small rotors using digital image correlation
Hrůza, Vlastimil ; Pokorný, Jan (referee) ; Ščerba, Bořek (advisor)
The presented thesis deals with the design of a method for aligning small rotors, for which commonly available methods are not suitable. This is due to space restrictions around the coupling, which often do not allow installation of conventional alignment systems on the shafts. The proposed method therefore utilizes non-contact measurement of the surface of the shafts using digital image correlation (DIC). Calculation of misalignment and corrective moves is based on fitting the points measured on individual shafts with cylinders and evaluating the mutual position of their axes. To determine the area of applicability of the proposed method, sensitivity analysis was performed, which showed that the method gives good results for surface-accurate shafts with a uniformly applied speckle pattern for DIC measurement. Validation of the method was then carried out by measuring on a designed test rig using a commonly available laser alignment system. The validation measurement proved the functionality of the method and confirmed the conclusions of the sensitivity analysis.
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Modification of a multi-recess hydrostatic bearing pad geometry
Šimara, Vít ; Robenek, Dětřich (referee) ; Svoboda, Petr (advisor)
In the design of a hydrostatic bearing, basic analytical expressions assuming parallelism of sliding surfaces and simple geometry can be employed. In this study, the properties of a specific pocket shape were investigated even under conditions of tilt, which can arise from assembly errors or asymmetric loading. Based on experimental data, a Computational Fluid Dynamics (CFD) model of hydrostatic lubrication has been developed and validated. A constant flow through all recesses was considered and conditions of no movement of the sliding surface were assumed. The model was subsequently modified to a variant with discharge grooves separating individual recesses and a variant with variable recess position relative to the centre of the pocket. The results demonstrated that the pocket's ability to carry asymmetric loading increases mainly with increasing distance of the recess from the centre, followed by their size. However, this ability comes at the cost of higher performance losses in hydrostatic lubrication. The results of this work can be used for the design of pockets with different methods of pocket support or alignment.
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The Constitution and the Subversion of the Exotic Myth
Binarová, Moe ; Voldřichová - Beránková, Eva (advisor) ; Hrbata, Zdeněk (referee) ; Kyloušek, Petr (referee)
The present dissertation outlines the main phases of the development of exoticism: its evolution from the discovery of Tahiti and its basic manifestations and transformations in French and Czech literature from the end of the eighteenth century to the 1930's. It focuses on the birth of the myth of Tahiti as a heavenly place (Bougainville), on its immediate philosophical interpretation in the period of Enlightenment (Diderot) and on its transposition to literature in a broader shape. At times, the island of Tahiti was gradually vanishing from the exotic myth behind another, more indefinite, exotic and ideal place, culture etc., while at other times, the presence of Tahiti was absolutely crucial. In the first half of the nineteenth century, the myth of the exotic paradise renewed literature and enriched it with new themes and motives (Chateaubriand, Romanticism), which, however, led progressively to the creation of simplified schemes and clichés. These, due to their repetitive nature, degraded the image of the myth (Loti). Although the superficial and unsophisticated adaptation of exoticism lasted until the twentieth century (Havlasa, Novák), in the meantime, from the second half of the nineteenth century, the myth of Tahiti was being radically reassessed and transposed to literature in a new way....
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