The literature concerning bluff-body flows in two-dimensional, incompressible, sheared and unsheared streams is reviewed. It is found that no theory yet exists which can predict the form drag of a bluff body without some recourse to experimental data, even for the simple case of an isolated bluff-plate in an unsheared stream. In the present state of knowledge, and considering the complexity of turbulent shear flows, a theory for the form drag of bluff-plates immersed in turbulent boundary-layers seems remote. A correlation scheme is proposed to relate the form drag of a bluff-plate which is attached to a smooth-wall with the mean-flow characteristics of the naturally-developed, turbulent boundary-layer in which it is immersed. The investigation is limited to smooth-wall flows of the type described by Coles (1956). It is suggested that, for bluff-plates which are small compared with the boundary-layer thickness, the drag might depend only on the “wall variables”: wall shear-stress, fluid density and viscosity, and the plate height.

Thesis (M.E.) -- University of Adelaide, Dept. of Mechanical Engineering, 1980. / Typescript (photocopy).

Thesis (M.S.)--Ohio University, March, 1989. / Title from PDF t.p.

Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 2002. / Thesis advisor(s): Kevin D. Jones, Max F. Platzer. Includes bibliographical references (p. 93-94). Also available online.

Thesis (Ph.D.)--University of Wyoming, 2008. / Title from PDF title page (viewed on June 25, 2009). Includes bibliographical references (p. 87-91).

Thesis (M.S.)--University of Wisconsin--La Crosse, 2002. / Includes bibliographical references.

Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xix, 167 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 148-151).

Submitted by Felipe Lapenda (felipe.lapenda@ufpe.br) on 2015-03-12T12:21:56Z No. of bitstreams: 2 DISSERTAÇÃO Marina Leitão Mesquita.pdf: 2312436 bytes, checksum: 85b0655d5663e7f4d1a6eb061ff73c84 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-12T12:21:56Z (GMT). No. of bitstreams: 2 DISSERTAÇÃO Marina Leitão Mesquita.pdf: 2312436 bytes, checksum: 85b0655d5663e7f4d1a6eb061ff73c84 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013 / Programa de Apoio a Planos de Reestruturação e Expansão das Universidades Federais / O objetivo deste trabalho consiste em analisar a prática do amadrinhamento entre transformistas e drag queens, buscando compreender os significados atribuídos ao estabelecimento de laços socioafetivos e às suas experiências concernentes a vivência transgênero. Para compreender tais questões, a metodologia empregada nesta pesquisa consistiu em descrever densamente os fenômenos relativos às experiências e às práticas das integrantes da família investigada, com o intuito de construir uma etnografia do amadrinhamento. Nesse sentido, observei seus processos de montagem corporal, que precedem a realização de espetáculos; compareci aos ensaios preparatórios para suas performances; acompanhei todo o planejamento e preparação de um importante espetáculo e compareci aos seus shows noturnos, atentando para as reações do público. Foram realizadas, também, entrevistas em profundidade semiestruturadas com seis membros do grupo. Foi possível observar que o amadrinhamento se configura em um tipo de relacionamento complexo, que se estabelece entre uma transgênero experiente e uma iniciante. A relação é principiada a partir do repasse do sobrenome e sugere que a preceptora auxilie, conceda apoio e ensine seus conhecimentos sobre as técnicas de montagem e performance. Reciprocamente, à iniciada caberá demonstrar sua gratidão e adotar uma série de exigências estéticas e comportamentais consideradas ideais pelo grupo. Portanto, há uma convergência entre práticas tradicionais e subversivas, no que tange às similitudes com o compadrio e à performance de gênero das artistas trans, que não se adequa a uma matriz heteronormativa, Engendram-se, ainda, relações de poder evidenciadas pela busca do prestígio e pela capacidade de proporcioná-lo através da doação do nome, articulando-se a relações recíprocas de transmissão de saberes e apoio mútuo.

Includes bibliographical references. / This thesis deals with a system that reduces the oncoming boundary layer displacement thickness in a wind tunnel. The device is then used to examine the effect that this boundary layer has on the aerodynamic drag of a standard truck, which is classified as a bluff body with a high ground clearance and the same truck fitted with skirts all round, which is then classified as a bluff body with a low ground clearance. To gain insight into this field of industrial aerodynamics, an extensive literature survey was done in which all the relevant SAE papers onwards from the late sixties were studied and summarised in the first section of this report. The second section deals with a system that can limit the boundary layer displacement thickness in the test section of the 3/4 open jet wind tunnel. Through investigations and an extensive literature research a suction device was designed and built. This boundary layer removal system was then tested to ensure that the main flow indicators are not influenced by the suction and thus lie within internationally accepted limits. Included in this section are a description of the truck model and the other instruments or devices used to complete the testing. The third section deals with the aerodynamic drag experienced by the bluff body with a high ground clearance. Included in the third section is an investigation that deals with the aerodynamic drag of the same truck model, when skirting has been added which considerably lowers the ground clearance. The results obtained from the above investigations indicate that the drag of the Ground Simulation model without skirts is increased by about 3.8% with the removal of the boundary layer and up to 10% for the model with the skirts. It is thus shown that the farther the object protrudes into the boundary layer, the larger the increase in drag will be once this boundary layer has been removed. These figures were obtained from testing the model at 22.2m/s free stream velocity and a 6mm wheel-ground clearance, with the wheels rotating.

The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the sphere. The formation of superhydrophobic sphere and attached air cavity reaches a steady state during the free fall. In this thesis we further explore this novel phenomenon to quantify the drag on streamlined shape cavities. The drag on the sphere-cavity formation is then compared with the drag on solid projectile which were designed to have self-similar shape to that of the cavity. The solid projectiles of adjustable weight were produced using 3D printing technique. In a set of experiments on the free fall of projectile we determined the variation of projectiles drag coefficient as a function of the projectiles length to diameter ratio and the projectiles specific weight, covering a range of intermediate Reynolds number, Re ~ 104 – 105 which are characteristic for our streamlined cavity experiments. Parallel free fall experiment with sphere attached streamlined air cavity and projectile of the same shape and effective weight clearly demonstrated the drag reduction effect due to the stress-free boundary condition at cavity liquid interface. The streamlined cavity experiments can be used as the upper bound estimate of the drag reduction by air layers naturally sustained on superhydrophobic surfaces in contact with water. In the final part of the thesis we design an experiment to test the drag reduction capacity of robust superhydrophobic coatings deposited on the surface of various model vessels.