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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
671

Návrh repliky letounu L-40 "Meta Sokol" - základní rozměry - technologie / Replica design of Aircraft "Meta Sokol" - Basic dimensions - technology

Lipková, Alica January 2008 (has links)
The object of the diploma thesis is a preparation of fundamentals for realization for replica of the aircraft L-40 „Meta Sokol“ matching the requirements of Certification Specification for Very Light Aeroplanes (CS-VLA). The preamble of the work deals with the changes made on the original aircraft necessary to satisfy the criterias of the above-mentioned specification. One of the main contents of the first part of the thesis is the definition of replica’s basic dimensions and preparation of aerostatic fundamentals, including longitudinal stability control. As next a suitable engine is chosen and calculation of corresponding performances is made. A detailed weight analysis and a determination of centre of gravity position (c.g. position), important for solving the stability of an airplane, is also presented. Finally, a brief description of the manufacturing process of individual components and also factors influencing the technology are discussed.
672

Konstrukční návrh letounu Avia BH534 v ultralehkém provedení / Avia BH534 airplane design as ultralight

Kozelský, Martin January 2010 (has links)
The object of the diploma thesis is a preparation of fundamental bases for realization aerofoils of the replica of the biplane aircraft BH534 Avia. The preambule of the work balances replica against the real historic aircraft. As next the basic aerodynamics characteristics, construction of aerofoils and strenght calculation of the aerofoils are described.
673

Návrh základní koncepce air - mobilu / Conceptual design of air- mobil

Podhorský, Matěj January 2014 (has links)
The topic of the thesis is a conceptual design of a roadable aircraft. The comparison of existing concepts is made, as well as description of proposed solution, aircraft mass analysis, basic aerostatic calculations, flight and gust envelope calculation and a design of truss construction of the fuselage. The CS-VLA, alternatively ELSA-K, has been used as a certification base. The compliance to this certification specification is one of the goals of this thesis.
674

Návrh zařízení pro měření aerodynamických sil a momentů v aerodynamickém tunelu / Design of device for measurement of aerodynamic forces and moments in wind tunnel

Brožek, Petr January 2014 (has links)
The masters thesis is focused on design of the device for measurement of the aerodynamic forces and moments acting on radiators mounted in the wind tunnel test section. The thesis also includes the analysis of the aerodynamic drag which is produced by radiators and the LabView application software development.
675

Stanovení hydrodynamického zatížení přelévané mostovky s využitím 2D numerických simulací / Quantification of hydrodynamic load on overflowed bridge deck using 2D numerical simulation

Pavlíček, Michal January 2016 (has links)
The diploma thesis is focused on a quantification of hydrodynamic load of overflowed bridge deck. Solution was pursued by using two–dimensional numerical simulation of open channel flow in vertical plane created in ANSYS 15.0 software (modules: Workbench, Design Modeler, Meshing, Fluent). Values of drag force, lift force, moment, drag coefficient, lift coefficient and moment coefficient is result of computation. Various types of bridge decks were tested in relation to the degree of inundation (inundation ratio) and flow velocity.The thesis provides comparison of numerical simulation with physical experimental testing and result published in accessible resources.
676

Performance Art and Agential Realism: Producing Material-Discursive Knowledge about Class and the Body.

Corbett, Karron January 2021 (has links)
Using new materialist approaches to intersectional theories of gender/sex –particularly Karen Barad’s ethico-onto-epistemological framework, agential realism– this thesis examines how knowledge about class is produced, through feminist performance art practices. Through this lens I will examine how two pieces of performance art by U.K. based artists, Sophie Lisa Beresford and Catherine Hoffmann, can express novel ways in which class is not simply a system acting upon bodies, but inextricably entwined with, and produced through, bodily matter. Furthermore, this essay discusses the ways in which performance art is uniquely positioned to examine this intra-action between discourse and matter; providing a way to bridge the gaps in the current theoretical discourses and creative practices. Keywords: Feminist performance art, agential realism, intersectionality, class, new materialism, class-drag, performativity, class-passing, intra-activity.
677

Stanovení hydrodynamického zatížení přelévané mostovky s využitím numerických simulací / Determination of hydrodynamic load acting on overflowed bridge deck using numerical simulations

Stoklas, Jan Unknown Date (has links)
The subjekt of this diploma thesis is a quantification of hydrodynamic load of the overflow bridge deck using numerical simulations. The simulation was performe for eight different discharges, which correspond to different degrees of inundation of the bridge deck using different turbulent models in Flow-3D software. The result of the calculation are the values of the hydrodynamic load– the horizontal force, the vertical force and the moment acting on the bridge deck. Furthermore, drag coefficient, lift coefficient and moment coefficient were quantified. Finally, the results of turbulent models were compared with each other and with result of physical experimental testing.
678

PIV Measurements of Turbulent Flow in a Rectangular Channel over Superhydrophobic Surfaces with Riblets

Perkins, Richard Mark 01 September 2014 (has links) (PDF)
In this thesis I investigate characteristics of turbulent flow in a channel where one of the walls has riblets, superhydrophobic microribs, or a hybrid surface with traditional riblets built on a superhydrophobic microrib surface. PIV measurements are used to find the velocity profile, the turbulent statistics, and shear stress profile in the rectangular channel with one wall having a structured test surface. Both riblets and superhydrophobic surfaces can each provide a reduction in the wall shear stress in a turbulent channel flow. Characterizing the features of the flow using particle image velocimetry (PIV) is the focus of this research. Superhydrophobicity results from the combination of a hydrophobic coating applied to a surface with microrib structures, resulting in a very low surface energy, such that the fluid does not penetrate in between the structures. The micro-rib structures are aligned in the streamwise flow direction. The riblets are larger than the micro-rib structure by an order of magnitude and protrude into the flow. All the test surfaces were produced on silicon wafers using photolithographic techniques. Pressure in the channel is maintained below the Laplace pressure for all testing, creating sustainable air pockets between the microribs. Velocity profiles, turbulent statistics, shear stress profiles, and friction factors are presented. Measurements were acquired for Reynolds numbers ranging from 4.5x10^3 to 2.0x10^4. Modest drag reductions were observed for the riblet surfaces. Substantial drag increase occurred over the superhydrophobic surfaces. The hybrid surfaces showed the greatest drag reduction. Turbulence production was strongly reduced during riblet and hybrid tests.
679

Soft Surface Roll Mechanics Parameters for Light Vehicle Rollover Accident Reconstruction

Henry, Kevin Claude 18 July 2007 (has links) (PDF)
Light vehicle rollover accidents on soft surfaces can be modeled assuming constant drag with linear motion equations and other engineering principles. The concept of using segment average results to evaluate roll mechanics parameters throughout a roll sequence, and specifically, segment duration to evaluate vehicle trajectory between ground impacts is developed. The trajectory model is presented, explained and compared to values obtained by analyzing digital video of rollover crash tests. Detailed film analysis procedures are developed to obtain data from rollover crash tests that are not otherwise documented. Elevation of the center of gravity of vehicles is obtained where instrumentation does not explicitly yield this data. Instantaneous center of gravity elevation data throughout a roll sequence provides the opportunity to calculate descend distances as a vehicle travels from one ground contact to another. This data is used to quantify severity of ground impacts as a vehicle interact with the ground throughout a roll sequence. Segment average analysis is a reasonable method for determining general roll mechanics parameters. Because of the chaotic nature of rollover accidents, the range of effective drag factors for a given roll surface may be quite large. Choosing an average of typical drag factors is a reasonable approach for a first-order approximation although certain parameters may be predicted less accurately than if actual values were known. The trajectory results demonstrate the influence of drag factor descent height calculations. Typical constant drag factors tend to overestimate descent height early in a roll sequence and underestimate descent height later in the sequence. The trajectory model is a useful tool to aid in understanding rollover mechanics although a rolling vehicle may be in contact with the ground for a significant fraction of a roll segment. The model should not be used at locations in roll sequences where there are extremes in translational center of gravity decelerations. These extremes include the segments immediately following overturn where there are large angular accelerations and large differences between the tangential velocity of the vehicle perimeter and the translational velocity of the center of gravity, as well as segments that include vehicle impacts with irregular topography.
680

Regression Models to Predict Coastdown Road Load for Various Vehicle Types

Singh, Yuvraj January 2020 (has links)
No description available.

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