scholarly journals Aerodynamic Interference between Oscillating Lifting Surfaces and Fuselage. Part 3: Some Applications of Oscillating Lifting Surface Theory to the Flapping Wing

2014 ◽  
Vol 6 (2) ◽  
pp. 15-24
Author(s):  
BUTOESCU Valentin Adrian Jean ◽  
Keyword(s):  
Flapping Wing ◽  
Surface Theory ◽  
Lifting Surface ◽  
Aerodynamic Interference ◽  
Lifting Surfaces

Application of the Unsteady-Lifting-Surface Theory to the Study of Propeller-Rudder Interaction

1970 ◽  
Vol 14 (03) ◽  
pp. 181-194
Author(s):  
S. Tsakonas ◽  
W. R. Jacobs ◽  
M. R. Ali
Keyword(s):  
Numerical Procedure ◽  
Ideal Incompressible Fluid ◽  
Operator Technique ◽  
Surface Integral ◽  
New Approach ◽  
Surface Theory ◽  
Lifting Surface ◽  
Harmonic Components ◽  
Lifting Surfaces ◽  
Interaction Problem

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- called "generalized lift operator" technique, a new approach developed by the authors, in conjunction with the presently used "mode-collocation" method. The analysis demonstrates the mechanism of the interaction phenomenon by exhibiting the filtering effects of the propeller on the harmonic constituents of the wake which allow the rudder to be exposed only to the blade harmonic and multiples thereof. A numerical procedure adaptable to the CDC 6600 computer has been developed which furnishes information about (i) the steady and time-dependent pressure distribution on both lifting surfaces, and (ii) the resultant hydrodynamic forces and moments. A limited number of calculations exhibit the importance of some parameters such as axial clearance, number of blades, and harmonic components of the hull wake.

Continuity of lifting surface theory in subsonic and supersonic flow

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 1788-1791
Author(s):  
Tetsuhiko Ueda
Keyword(s):  
Supersonic Flow ◽  
Surface Theory ◽  
Lifting Surface

Unsteady Lifting Surface Theory for a Rotating Cascade of Swept Blades

1989 ◽  
Author(s):  
Hidekazu Kodama ◽  
Masanobu Namba
Keyword(s):  
Three Dimensional ◽  
Acoustic Power ◽  
Aerodynamic Characteristics ◽  
Blade Loading ◽  
Surface Theory ◽  
Numerical Examples ◽  
Lifting Surface ◽  
Blade Flutter ◽  
Annular Cascade ◽  
Remarkable Reduction

A lifting surface theory is developed to predict the unsteady three-dimensional aerodynamic characteristics for a rotating subsonic annular cascade of swept blades. A discrete element method is used to solve the integral equation for the unsteady blade loading. Numerical examples are presented to demonstrate effects of the sweep on the blade flutter and on the acoustic field generated by interaction of rotating blades with a convected sinusoidal gust. It is found that increasing the sweep results in decrease of the aerodynamic work on vibrating blades and also remarkable reduction of the modal acoustic power of lower radial orders for both forward and backward sweeps.

Lift Control Using MEMS-Based Moving Trailing-Edge Tabs

2002 ◽  
Author(s):  
C. P. van Dam ◽  
C. Bauer ◽  
D. T. Yen Nakafuji
Keyword(s):  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Trailing Edge ◽  
Aircraft Wings ◽  
Lifting Surface ◽  
Lifting Surfaces ◽  
Lift Control

Micro-electro-mechanical (MEM) translational tabs are introduced for active lift control on aircraft. These tabs are mounted near the trailing edge of lifting surfaces such as aircraft wings and tails, deploy approximately normal to the surface, and have a maximum deployment height on the order of one percent of the section chord. Deployment of the tab effectively changes the sectional camber, thereby changing the aerodynamic characteristics of a lifting surface. Tabs with said deployment height generate a change in the section lift coefficient of approximately ±0.3. The microtab design and the techniques used to fabricate and test the tabs are presented.

Lifting-Surface Theory for an Oscillating T-Tail

AIAA Journal ◽  
1974 ◽  
Vol 12 (1) ◽  
pp. 28-37 ◽  
Author(s):  
KOJI ISOGAI
Keyword(s):  
Surface Theory ◽  
Lifting Surface

New directions in lifting surface theory

1964 ◽  
Author(s):  
H. ASHLEY ◽  
M. LANDAHL
Keyword(s):  
Surface Theory ◽  
Lifting Surface ◽  
New Directions

Derivation by a Transform Method of Integral Equations of Unsteady Lifting Surface Theory in Subsonic and Supersonic Flow

1979 ◽  
Vol 30 (4) ◽  
pp. 529-543
Author(s):  
Shigenori Ando ◽  
Akio Ichikawa
Keyword(s):  
Fourier Transforms ◽  
Integral Transforms ◽  
Physical Models ◽  
Streamwise Direction ◽  
Fourier Inversion ◽  
Transform Method ◽  
Inviscid Flows ◽  
Surface Theory ◽  
Method Of Integral Equations ◽  
Lifting Surface

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 that the streamwise Fourier inversion in the subsonic case requires some caution. Concepts based on the theory of distributions seem to be essential, in order to solve the convergence difficulties of integrals. Apart from this caution, the method of integral transforms of in-plane coordinate variables makes it be pure-mathematical to formulate the lifting surface problems, and makes aerodynamicist’s experiences and physical models such as vortices or doublets be useless.

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