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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.
141

Happy Trails

Derby, Elizabeth A 13 May 2016 (has links)
My work uses hair as both a subject depicted in drawings, paintings, and prints; as well as a medium for sculpture, installation, and video created with synthetic hair pieces and wigs. I am interested in deconstructing gendered codes of appearance, and visions of the ideal woman and man as objects. I remove all identifiable traits from my characters, apart from their hair which appears to be consuming or erasing them. In doing so, I force the people viewing my work to rely on cultural stereotypes associated with hair to identify my characters. My work is heavily influenced by Drag culture and Camp, for their ability to mock identity, gender, and cultural stereotypes and portray them as something fluid that can be constructed and changed on a daily basis, instead of a biological trait forced upon them at birth. I view my artwork as my own form of Drag.
142

The determination of form drag coefficient for rigid, emergent objects in open channel flow

Jackson, Kyle Sheldon January 2017 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Engineering Johannesburg, 2017 / The development of methods which are better able to predict the effect of large scale emergent roughness elements on the flow characteristics requires a better understanding of the drag coefficient under conditions likely to occur in the field. A laboratory investigation was carried out with newly developed equipment to quantify the drag force on various shaped cylinders, as well as the drag on an individual cylinder surrounded by an array of cylinders. The relationship between the drag coefficient and cylinder Reynolds number for a single circular cylinder was found to be of similar form but larger in magnitude than the established relationship for an infinitely long cylinder; the relationship departs from the infinite cylinder relationship for low cylinder Reynolds numbers. Contrary to previous research, the results for the multiple cylinder investigation did not reveal a clear relationship between the cylinder density and drag coefficient. Equations were developed and verified with existing laboratory data. These should be improved and extended by further research for field use. / MT2017
143

LES Modeling of Flow through Vegetation with Applications to Wildland Fires

Mueller, Eric Victor 26 April 2012 (has links)
Due to continued outward expansion of industry and community development into the wildland-urban interface (WUI), the threat to life safety and property from wildland fires has become a significant problem. Such fire scenarios can be better understood through the use of computation fluid dynamics based fire-spread models. However, current physical fire models must be specifically adapted to handle the phenomena associated with WUI fires. Only then can they be reliably used as research and decision making tools to help mitigate the problem. In this research, the current standard in wildland fire modeling for representing the effect on wind flow from a porous vegetative medium is examined. The technique used employs basic correlations for object drag, and its validity with respect to real vegetation has yet to be examined in detail by the scientific community. The modeling of vegetation is studied within the framework of the existing Wildland-Urban Interface Fire Dynamics Simulator (WFDS), and the potential need for continued development is assessed. Comparisons are made to both experimental and numerical studies. Additionally, the validity of the model is considered at both the scale of an individual tree, as well as that of a whole forest canopy. Results show that as a first approximation the model is able to perform well in the latter case. At the scale of an individual tree, however, the behavior is governed by theoretical constants. The assumption of cylindrical vegetation elements performs slightly better than the commonly used spherical case, but neither adequately captures experimental tendencies. Accurate flow representation for single trees is crucial to modeling the key driving factors of fire behavior (such as combustion and heat transfer) in small scale WUI scenarios. Ultimately, this study illustrates the need for well-designed experiments, specifically to generate empirical constants which will improve the behavior of the simplified theory.
144

A study of the lift-to-drag ratio capability of caret wing waveriders.

Solomon, Marshall David January 1977 (has links)
Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND AERONAUTICS. / Includes bibliographical references. / M.S.
145

Experimental Investigations of Core-Loc Armour Units

Simpalean, Adrian Raul 25 January 2019 (has links)
In the present study, the influence of geometric scale, unit orientation (alternatively, flow direction), and the dimensionless Reynolds and Keulegan-Carpenter quantities on the hydrodynamic loading of Core-Loc armour units is explored through a series of physical modelling tests under unsteady and oscillatory flow conditions.
146

Drag Reduction in Turbulent Pipe Flow by Transverse Wall Oscillations at Low and Moderate Reynolds Number

January 2019 (has links)
abstract: This work helps to explain the drag reduction mechanisms at low and moderate turbulent Reynolds numbers in pipe flows. Through direct numerical simulation, the effects of wall oscillations are observed on the turbulence in both the near wall and the bulk region. Analysis of the average Reynolds Stresses at various phases of the flow is provided along with probability density functions of the fluctuating components of velocity and vorticity. The flow is also visualized to observe, qualitatively, changes in the total and fluctuating field of velocity and vorticity. Linear Stochastic Estimation is used to create a conditional eddy (associated with stress production) in the flow and visualize the effects of transverse wall oscillations on hairpin growth, auto-generation and structure. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2019
147

Effect of End-Plate Tabs on Drag Reduction of a 3D Bluff Body with a Blunt Base

Pinn, Jarred Michael 01 March 2012 (has links)
This thesis involves the experimental testing of a bluff body with a blunt base to evaluate the effectiveness of end-plate tabs in reducing drag. The bluff body is fitted with interchangeable end plates; one plate is flush with the rest of the exterior and the other plate has small tabs protruding perpendicularly into the flow. The body is tested in the Cal Poly 3ft x 4ft low speed wind tunnel. Testing is conducted in three phases. The first phase was the hot-wire measurement of streamwise velocity of the near wake behind the bluff body. An IFA300 thermal anemometry system with a hot-wire probe placed behind the model measures the wake velocity fluctuations. The power spectral density on the model without tabs shows large spikes at Strouhal numbers of 0.266, 0.300, and 0.287 at corresponding Re = 41,400, 82,800, 124,200 where vortex shedding occurs. The model with tabs shows no such peaks in power and therefore has attenuated vortex generation in the wake flow at that location. The second phase of testing was pressure testing the model through the use of pressure ports on the exterior of the bluff body. A Scanivalve pressure transducer measured multiple ports almost simultaneously through tubing that was connected to the model internally and routed through the model’s strut mount and outside of the wind tunnel. This pressure testing shows that the model with tabs is able to achieve up to 36% increase in Cp at Reh = 41,400 on the base region of the bluff body and no negative pressure spikes that occur as a result of vortex shedding. The last phase of testing is the measurement of total drag on the model through a sting balance mount. This testing shows that the drag on the model is reduced by 14% at Re = 41,400. However it also shows that as velocity increased, the drag reduction is reduced and ultimately negated at Re = 124,200 with no drag loss at all. The addition of tabs as a passive flow control device did eliminate vortex shedding and alter the base pressure of the bluff body. This particular model however showed no reduction in total drag on the model at high Reynolds numbers higher than 124,000. Further study is necessary to isolate the exact geometry and flow velocities that should be able to produce more favorable drag results for a bluff body with this type of passive flow control device.
148

"Yo soy una drag queen, no soy cualquier loco". Representaciones del dragqueenismo en Lima, Perú / "I am a drag queen, Not Just a Crazy Man". Representations of dragqueenism in Lima, Peru

Villanueva Jordán, Iván 07 1900 (has links)
El estudio exploratorio sostiene que el dragqueenismo surge de procesos de representación por parte de las drag queens, mediante sus prácticas discursivas y la manera en que se exhiben frente a un público. Estas representaciones les permiten, en su dimensión productiva, establecer una base identitaria que, en una dimensión reactiva, las diferencia de otras identidades transgénero. El análisis de los datos obtenidos mediante entrevistas semiestructuradas a drag queens de Lima (Perú) permitirá identificar la manera en que articulan las representaciones en torno a la tradición, la poética y el arte del dragqueenismo. / Revisión por pares
149

An investigation of flow structure interactions on a finite compliant surface using computational methods

Pitman, Mark William January 2007 (has links)
A study of the interaction of one-sided flow over a compliant surface is presented. When fluid passes over a flexible surface the simultaneous interaction between the flow and structure gives rise to vibrations and instabilities on the surface as well as in the fluid. The fluid-structure interaction (FSI) has potential to be used in the control of boundary layer dynamics to achieve drag reduction through transition delay. The modelling and control of FSI systems apply to many fields of engineering beyond drag reduction, for example: the modelling and analysis of biomechanical systems; natural environmental systems; aero-elastics; and other areas where flow interacts moving or compliant boundaries. The investigation is performed through numerical simulation. This returns more detail than could be resolved through experiments, while also permitting the study of finite compliant surfaces that are prohibitively difficult, or impossible, to study with analytical techniques. In the present work, novel numerical modelling methods are developed from linear system analysis through to nonlinear disturbances and viscous effects. / Two numerical modelling techniques are adopted to approach the analysis of the FSI system. A potential-flow method is used for the modelling of flows in the limit of infinite Reynolds numbers, while a grid-free Discrete Vortex Method (DVM) is used for the modelling of the rotational boundary-layer flow at moderate Reynolds numbers. In both inviscid and viscous studies, significant contributions are made to the numerical modelling techniques. The application of these methods to the study of flow over compliant panels gives new insight to the nature of the FSI system. In the linear inviscid model, a novel hybrid computational/theoretical method is developed that evaluates the eigenvalues and eigenmodes from a discretised FSI system. The results from the non-linear inviscid model revealed that the steady-state of the non-linear wall motion is independent of initial excitation. For the viscous case, the first application of a DVM to model the interaction of a viscous, rotational flow with a compliant surface is developed. This DVM is successfully applied to model boundary-layer flow over a finite compliant surface.
150

CROSS[DRESS]ING BOUNDARIES : En tematisk queeranalys av Sarah Waters Tipping the Velvet och Jeanette Wintersons Written on the Body

Säfwenberg, Nike Linn January 2007 (has links)
<p>The aim of this essay is to answer the question of how – in what ways – Jeanette Wintersons Written on the Body and Sarah Waters’ Tipping the Velvet are queer texts. My method is that of a thematic analysis, focusing on words and phenomenon related to definitions of the multi facetted term “queer”. The analysis covers themes of lesbian focus, performativity, performance, speech-acts, and heteronormative and queer relationships. My results are presented in a dialogue between the novels themes and queer theory, foremost represented by Judith Butler. My conclusion is that the literary texts are indeed queer, in several ways, and that both of them, although different, serve important queer purposes.</p>

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