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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.
1

Aerodynamic pitch-up of cranked arrow wings : estimation, trim, and configuration design /

Benoliel, Alexander M., January 1994 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 51-56). Also available via the Internet.
2

Numerical prediction of the impact of non-uniform leading edge coatings on the aerodynamic performance of compressor airfoils /

Elmstrom, Michael E. January 2004 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Knox Millsaps. Includes bibliographical references (p. 69-72). Also available online.
3

Interactions of a quasi-two-dimensional vortex with a stationary and oscillating leading-edge /

Jefferies, Rhett William, January 1996 (has links)
Thesis (Ph. D.)--Lehigh University, 1996. / Includes vita. Bibliography: leaves 155-158.
4

Impact of leading-edge orientation and shape on performance of a compressor blade

Powell, Jonathan D. 06 1900 (has links)
Approved for public release, distribution unlimited / This thesis presents a Computation Fluid Dynamics (CFD) analysis of the aerodynamic performance of circular and elliptical leading edges of compressor blades, with a range of leading-edge droop angles. Specifically, simulations were conducted, with a free stream Mach number of 0.65 to quantify the change in pressure distributions and boundary layer momentum thickness in the leading edge region for a range of incidences on a flat plate with various leading-edge ellipticity ratios, ranging from unity (circular) to 5.5. In addition, the impact of drooping the leading edge was analyzed over a range of incidence angles from zero to 13 degrees. Pressure distributions indicate that elliptical leading edges can eliminate separation bubbles at zero incidence. The results indicated that the minimum loss occurred at an ellipticity ratio of about 3 and elliptical leading edges with a droop slightly greater than the average incidence can significantly decreased aerodynamic losses over a wider range of incidences.
5

A Method for Computing Spectral Reflectance

Yuille, A. 01 December 1984 (has links)
Psychophysical experiments show that the perceived colour of an object is relatively independent of the spectrum of the incident illumination and depends only on the surface reflectance. We demonstrate a possible solution to this undetermined problem by expanding the illumination and surface reflectance in terms of a finite number of basis functions. This yields a number of nonlinear equations for each colour patch. We show that given a sufficient number of surface patches with the same illumination it is possible to solve these equations up to an overall scaling factor. Generalizations to the spatial dependent situation are discussed. We define a method for detecting material changes and illustrate a way of detecting the colour of a material at its boundaries and propagating it inwards.
6

Numerical investigation of the effect of leading edge geometry on dynamic stall of airfoils

Grohsmeyer, Steven P. January 1990 (has links) (PDF)
Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Ekaterinaris, John A. ; Platzer, Max. "September 1990." Description based on title screen as viewed on December 21, 2009. DTIC Identifier(s): Dynamics, leading edges, airfoils, dynamic stall, oscillating airfoil, pitching airfoil, leading edge geometry, pressure gradient, theses. Author(s) subject terms: Dynamic stall, oscillating airfoil, pitching airfoil, leading edge geometry, pressure gradient. Includes bibliographical references (p. 111-112). Also available in print.
7

Impact of leading-edge orientation and shape on performance of a compressor blade /

Powell, Jonathan D. January 2005 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Knox T. Millsaps. Includes bibliographical references (p. 73-74). Also available online.
8

Aerodynamics of transonic turbine trailing edges

Melzer, Andrew Philip January 2018 (has links)
No description available.
9

Zpracování vybraných částí techniky a metodiky carvingu formou DVD \\ / Selected Methods and Techniques of Ski Carving on a DVD

KRATOCHVÍL, Petr January 2009 (has links)
Almost 15 years are carving ski on the market. They differ from ordinary skis by great side carve. Regardless the public still ski with the normal techniques and skiers are not able to enjoy the new dimension of skiing which is carving. The aim of my Diploma Thesis is to make a DVD with selected methods and techniques o ski carving. Clarify the differences between the old-school-skiing and the new modern style. By use of simple exercises gain the first feelings of ride on the edges and step by step improve it until the full control of each type of carving like for example Fun carving or the ride reminding the racers in the giant slalom.
10

Influence of Afterbody Rounding on the Aerodynamics of a Fastback Vehicle / Influence des montants arrières arrondis sur l'aérodynamique des véhicules bicorps

Rossitto, Giacomo 07 September 2016 (has links)
Pendant les dernières décennies les constructeurs automobiles ont été confrontés à la tâche difficile de réduire la consommation de carburant et les émissions de CO2. En réponse à cela, des processus d'optimisation ont été appliquées pour générer de nouvelles formes de véhicule pour réduire la traînée aérodynamique. Malheureusement, les formes optimales obtenues n’ont aucun signe distinctif pour se différentier entre les différentes marques. Les stylistes tentent aujourd'hui de redonner une signature de marque en proposant des formes «non-conventionnelles» caractérisés par des montants arrières fortement arrondis.Ce travail de thèse quantifié expérimentalement l'influence des montants arrondis sur l’aérodynamique des véhicules bi-corps (fastback). Rayonner l’arrêt entre le pavillon et la lunette du corps d’Ahmed s’avère efficace pour réduire la trainée. Ajouter un rayon de courbure sur les montants arrière latéraux ne modifie pas davantage la traînée. Cependant, l'effet net nul sur la trainée est dû à des modifications de traînée opposée.L'organisation du sillage proche et le transport de vorticité ont été analysés et relié à l'augmentation locale de la traînée. Pour augmenter encore la complexité et de la fidélité du modèle, un modèle a été réalisé en partenariat avec le département du style de PSA. La sensibilité au vent latéral a également été étudiée. Il a été montré que les montants arrières arrondis détériorent les performances en vent latéral. La compréhension des effets d'arrondi de la partie arrière des modèles de véhicule s’avère être valide malgré la complexité croissante des modèles. Enfin, des tests à l’échelle 1 on confirme les tendances observées sur les modèles à échelle réduite. / For the last decades car manufacturers have been facing the challenging task of reducing fuel consumption and CO2 emissions. In response to that, optimization processes have been applied to generate new vehicle shapes minimizing the aerodynamic drag. Since the obtained optimal shapes have no brand differentiating details, stylists are nowadays trying to give back a brand signature by proposing "non-conventional" shapes characterized by important rear pillars rounding. The present PhD work experimentally quantifies the influence of such afterbody rounding on the aerodynamic loads and on the flow field development over fastback vehicle models.Rounding the roof/backlight of the well-known Ahmed body intersection is shown to reduce drag. Surprisingly, additional rear curvature associated with side pillars rounding does not further modify the drag. However, the zero net effect is found to result from opposite drag effects. To further increase the complexity and fidelity of the model, a model is realized in partnership with the style department of PSA. Crosswind sensitivity is also investigated by means of yaw angle variation. It is shown that the rear ends with rounded edges deteriorate the lateral. The understanding of the afterbody rounding effects is shown to be valid even for increasing complexity of the models. Finally, full scale test confirms the trends observed with the scaled models.

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