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Performance analysis and prediction of high speed planing craftBate, John January 1994 (has links)
A comprehensive and critical review of literature pertaining to the study of planing craft is given within this work. This study includes monohull design, analysis and performance prediction for flat water; many features of the planing characteristics, including dynamic stability, the use of stepped hullforms, re-entrant transoms and flow characteristics are detailed. Work on the rough water seakeeping analysis of planing craft is also given, and furthermore, literature pertaining to planing catamaran design and performance prediction, and on the ground effect is cited. Mathematical modelling approaches are discussed and it is explained that there is still much progress to be made in this area before accurate and reliable analytical prediction methods become available. The method of matched asymptotic expansions and also a proposed force-mathematical model are shown to be particularly suitable to the prediction of planing craft forces and moments, the first method being highly analytical and the latter requiring a semi-empirical approach to be adopted. A discussion is given of the physical phenomena responsible for the characteristics of planing craft and their interrelation. It is also discussed how modem craft are attaining higher and higher speeds, and a result of this is that the dynamic characteristics of the craft, including the flow conditions, are substantially different to those of more conventional craft. This modem very high speed regime of planing has been analysed and identified in this study under the new title of 'Alto-planing'. Further discussion of planing craft form and design concepts are persued, including details of the design of catamarans and more novel forms. A new computer-based prediction method is presented, which includes prediction methods for trim tabs and an aero foil. The ability of the program to allow the designer to vary given inputs of the hull data is explained, and a systematic variation of all the input characteristics is detailed. An optimisation procedure is offered and it is observed that this new prediction method can provide the designer with as much data as required for analysis of the form, a distinct advantage over current planing craft prediction software. Validation is undertaken by comparison with data from trials results, model test data and comparison with other prediction techniques. A discussion of current prediction methods is given. Finally, the aerodynamic characteristics of alto-planing craft are researched in detail, by means of a systematic series of model tests. Analysis of the results have extended the previous empirical limits and have furthermore segregated and quantified the components of the aerodynamic effects, including the aerodynamic resistance and the change in hydrodynamic running conditions due to the aerodynamic effects. An enhanced and novel prediction method is given, which is used to provide illustrative examples of the aerodynamic characteristics of alto-planing craft.
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Unsteady low Reynolds number aerodynamic forcesStevens, Patrick Robert Robbie James January 2015 (has links)
No description available.
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The effects of pulsing and blowing ratio on a 45�� inclined jet in cross flowStander, Arjan 29 October 2002 (has links)
The effect of jet flow pulsing and blowing ratio on a jet in cross flow has
been investigated. Preliminary jet flow studies were performed without cross flow
and an extensive study of jet with cross flow was done for a total of nine test
cases. The effect of velocities ratios of 0.85 and 3.4, as well as pulsing the jet flow
at 20Hz, was investigated in the near and far field of the jet. A comparison
between the jet in cross flow and an inclined cylinder in cross flow was also
performed.
Hot film measurements were taken within a grid of the flow field in the jet
symmetry plane and out of the symmetry plane. Instantaneous velocities were
generated at each location and mean velocity, RMS values, Reynolds stresses and
mean vorticity were calculated and compared for each case.
The higher velocity ratio case (VR=3.4) caused the jet flow to lift up
from the wall penetrating into the cross flow compared to the lower velocity ratio
case (VR=0.85) where the jet fluid remained attached to the wall and no lift off
was observed. The higher velocity ratio case resulted in increased mean
velocities, RMS values, Reynolds stresses and mean vorticity throughout the flow
field compared to the low velocity ratio case. Secondary turbulent structures were
discovered in the wake region of the inclined cylinder. Similar structures were
absent in the downstream flow region during the jet in cross flow experiments.
There was no significant effect on the jet trajectory as a result of jet
pulsing. For both velocity ratio cases the jet trajectory remained similar to the
steady cases. Jet pulsing increased the instantaneous velocity RMS levels and
Reynolds stresses in the near field of the jet, but did not seem to affect the RMS
levels and Reynolds stresses beyond x/d=4.
Jet pulsing had a significant effect on the distribution of spectral energy.
Distinct energy peaks are generated at the pulsing frequency and its harmonics.
The distinct spectral peaks were largest close to the jet exit and within the jet
flow, but were detectable throughout the entire flow field. / Graduation date: 2003
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Electric propulsion and controller design for drag-free spacecraft operation in low earth orbitMarchetti, Paul J. January 2006 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords:Spacecraft; electric propulsion; LEO; GRACE; Drag-free. Includes bibliographical references (leaves 111-112).
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Aerodynamic drag of a two-dimensional external compression inlet at supersonic speed /Esterhuyse, J. C. January 1997 (has links)
Thesis (D.Tech.-Mechanical engineering)--Cape Technikon, 1997. / Includes bibliography. Also available online.
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Unsteady boundary layer separation /Zalutsky, Konstantin E., January 2000 (has links)
Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 186-192).
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Verfahren zur Berechnung des Auftriebes gegebener Tragflächen-ProfileHöhndorf, Fritz, January 1926 (has links)
Thesis (doctoral)--Friedrich-Wilhelms-Universität zu Berlin, 1926. / "Sonderabdruck aus: Zeitschrift für angewandte Mathematik und Mechanik, Band 6, 1926, Seite 265 bis 283"--P. [1]. Vita. Includes bibliographical references.
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On the formation of vortex breakdown over delta wings /Sutthiphong Srigrarom. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 185-191).
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Hessert transonic free shear layer facilityChouinard, Mitchell. January 2004 (has links)
Thesis (M.S.)--University of Notre Dame, 2004. / Thesis directed by Eric J. Jumper for the Department of Aerospace and Mechanical Engineering. "April 2004." Includes bibliographical references (leaves 66-68).
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Aerodynamic coefficients of a symmetrical airfoil in an oscillating flowChamberlain, George A. January 1990 (has links) (PDF)
Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Miller, James A. Second Reader: Schmidt, Louis V. "September 1990." Description based on title screen viewed on December 17, 2009. DTIC Descriptor(s): Velocity, angles, air flow, angle of attack, airfoils, cycles, time, surfaces, three dimensional, flow rate, coefficients, symmetry, pressure, axes, aerodynamic characteristics, value, unsteady flow, drag, oscillation, free stream, static pressure, pressure distribution, plotting, steady flow, control. DTIC Identifier(s): Airfoils, oscillating flow, pressure measurement, turbulence, moments, aerodynamic lift, aerodynamic drag, aerodynamic coefficients, wind tunnel tests, rotor blades(rotary wings), random variables, symmetrical airfoils, theses. Author(s) subject terms: Oscillating flow, aerodynamic coefficients, symmetrical airfoil. Includes bibliographical references (p. 94). Also available in print.
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