Results 141 to 150 of about 13,317 (179)

Application of unsteady lifting surface theory to propellers in forward flight

15th Structural Dynamics and Materials Conference, 1974
Development of a theory for determining the aerodynamic forces for unsteady, compressible subsonic flow on a propeller in forward flight. The acceleration potential method is used in developing the basic downwash integral equation which governs the flow.
C. HAMMOND, H. RUNYAN, J. MASON
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Unsteady Propeller Lifting-Surface Theory With Finite Number of Chordwise Modes

Journal of Ship Research, 1968
A continuing investigation at Davidson Laboratory is concerned with improvement of the mathematical model developed for the evaluation of the steady and time-dependent distributions on the blades of marine propellers operating in spatially nonuniform flow.
S. Tsakonas, W. R. Jacobs, P. H. Rank
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Propeller Loading-Induced Velocity Field by Means of Unsteady Lifting Surface Theory

Journal of Ship Research, 1973
An analysis based on the lifting surface theory has been developed for evaluation of the vibratory velocity field induced by the loading of an operating propeller in both uniform and nonuniform inflow fields. The analysis demonstrates that in the case of nonuniform flow the velocity at any field point is made up of a large number of combinations of the
W. R. Jacobs, S. Tsakonas
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Alternative solution of the kernel function in subsonic unsteady lifting surface theory

AIAA Journal, 1995
The purpose is to outline an approach to the approximation of the kernel function. To this end, the kernel function has been approximated with a portion of the integrand in the kernel replaced with a simple curve fit. This curve fit employs functions that render the integrand readily integrable.
Epstein, Ronald J., Bliss, Donald B.
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Application of the Unsteady-Lifting-Surface Theory to the Study of Propeller-Rudder Interaction

Journal of Ship Research, 1970
The propeller-rudder interaction problem is studied by means of the unsteady-lifting- surface theory. Both surfaces of arbitrary geometry are immersed in a non-uniform flow- field (i.e., hull wake) of an ideal incompressible fluid. The boundary-value problem yields a pair of surface integral equations, the inversion of which is achieved by the so ...
S. Tsakonas, W. R. Jacobs, M. R. Ali
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The Difference Property of the Kernel of the Unsteady Lifting Surface Theory

Journal of the Aeronautical Sciences, 1955
The kernel of the integral representation of the general solution of the linearized lifting surface theory has the difference property. This leads to two corresponding forms of solution which give the unsteady reverse-flow theorem. From the difference property a condition of compatibilit}^ is obtained for the characteristic function G of the kernel of ...
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Theory of the lifting surface in unsteady motion in an inviscid fluid

Acta Mechanica, 1977
This paper considers the linearised unsteady motion of a lifting surface in a perfect fluid, proceeding from the fluid mechanics equations written in terms of distributions. A singular integral equation which determines the pressure on the lifting surface is deduced. The particular case of the lifting surface which moves over a (fictitious) cylindrical
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Derivation by a Transform Method of Integral Equations of Unsteady Lifting Surface Theory in Subsonic and Supersonic Flow

Aeronautical Quarterly, 1979
SummaryApplications of “integral transforms of in-plane coordinate variables” in order to formulate unsteady planar lifting surface theories are demonstrated for both sub- and supersonic inviscid flows. It is concise and pithy. Fourier transforms are exclusively used, except for only Laplace transform in the supersonic streamwise direction. It is found
Shigenori Ando, Akio Ichikawa
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Unsteady Lifting Surface Theory for a Marine Propeller of Low Pitch Angle With Chordwise Loading Distribution

Journal of Ship Research, 1965
This study is third in a series of investigations applying the unsteady lifting-surface theory to the marine propeller case. In the present investigation, the surface integral equation is solved for a mathematical model where the chordwise loading is taken as the first term of Birnbaum's lift distribution (flat-plate chordwise distribution), in ...
S. Tsakonas, W. R. Jacobs
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Unsteady Lifting-Surface Theory for Ship Screws: Derivation and Numerical Treatment of Integral Equation

Journal of Ship Research, 1975
In an early stage of studies concerned with lifting-surface theory for ship screws, the Netherlands Ship Model Basin initiated the development of a numerical solution of the mathematical model. To achieve this, a rigorous method was followed consisting of separation of regular and singular parts of the kernel of the integral equation, preparation of ...
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