Results 181 to 190 of about 1,190 (227)

Unsteady Aerodynamic Forces Measured on a Fluttering Profile

Volume 4: Fluid-Structure Interaction, 2014
The study presents evaluation of optical measurements of the air flow field near the fluttering profile NACA0015 with two-degrees of freedom, Mach number of the flutter occurrence were M=0.21 and M=0.45. Aerodynamic forces (drag and lift components) were evaluated independently on the upper and lower surfaces of the profile.
Igor Zolotarev, Václav Vlček, Jan Kozánek   +2 more
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Aerodynamic Force Modeling for Unsteady Wing Maneuvers

52nd Aerospace Sciences Meeting, 2014
Abstract : We report on the development of an aerodynamic force model for a at-plate wing undergoing unsteady motions of surging, pitching, and the combination thereof in two- dimensional ow. This investigation aims to extend the conventional quasi-steady aero- dynamic theory to account for the influence of large-scale vortices generated from the ...
Ryan T. Jantzen, Kunihiko Taira, Kenneth Granlund, Michael V. Ol   +3 more
openaire   +1 more source

Unsteady supersonic aerodynamic forces on an oscillating circular cylindrical shell.

AIAA Journal, 1971
Unsteady supersonic aerodynamic forces on an oscillating circular cylindrical shell are derived from the linearized equation of a potential flow on the basis of the assumption of circumferential wave number n ^> 1. The generalized aerodynamic forces calculated by the present aerodynamic theory are compared with those of the "exact" theory, the ...
Matsuzaki, Yuji, Kobayashi, Shigeo
openaire   +2 more sources

Modeling the unsteady aerodynamic forces of a maneuvering rotor

Aircraft Engineering and Aerospace Technology, 1999
The details of predicting the aerodynamic forces of maneuvering helicopter rotors are discussed in this paper. A new approach to modeling the unsteady rotor aerodynamic forces is presented based on the insight into nonuniform induced velocity distribution, inflow dynamics and unsteady airfoil behavior. For a specified maneuver, the rotor control inputs
openaire   +1 more source

The 3D Unsteady Aerodynamic Forces: The Forced Vibration of Bladed Discs

1998
The main problem for a bladed disc assembly under running conditions is the response levels when the excitation frequencies coincide natural frequencies of the structure during operation. Generally in the bladed analysis the excitation force are assumed in advance, although there are papers where these forces were calculated from the very simple flow ...
V. Gnesin, R. Rządkowski
openaire   +1 more source

Aerodynamic force by Lamb vector integrals in unsteady compressible flows

International Journal of Numerical Methods for Heat & Fluid Flow
Purpose This study aims to propose an aerodynamic force decomposition which, for the first time, allows for thrust/drag bookkeeping in two-dimensional viscous and unsteady flows. Lamb vector-based far-field methods are used at the scope, and the paper starts with extending recent steady compressible formulas to the unsteady regime.
Mauro Minervino, Renato Tognaccini
openaire   +3 more sources

Parameter identification of unsteady aerodynamic forces for elastic vehicles

Astrodynamics Conference, 1992
In this paper, a method for identifying unsteady aerodynamic forces of elastic vehicles is proposed. We utilize the concept of "indicial function" to establish the practical mathematical model for the consideration of unsteady aerodynamic forces. A standard measurement equation satisfied by aerodynamic indicia1 functions is derived fromlongitudinal ...
CHEN SHILU, XIAOFEI XIONG
openaire   +1 more source

Modeling the Unsteady Aerodynamic Forces on Small-Scale Wings

47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition, 2009
The goal of this work is to develop low order dynamical systems models for the unsteady aerodynamic forces on small wings and to better understand the physical characteristics of unsteady laminar separation. Reduced order models for a fixed, high angle of attack flat plate are obtained through Galerkin projection of the governing Navier-Stokes ...
Steven Brunton, Clarence Rowley
openaire   +1 more source

The computation of second-order accurate unsteady aerodynamic generalized forces

26th Structures, Structural Dynamics, and Materials Conference, 1985
A classical variational statement is used to derive special properties of a weighted residual method. It is shown that some weighted integral of the sought solution can be obtained to second-order accuracy in the solution to the original and adjoint problems.
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Method of Unsteady Aerodynamic Forces Approximation for Aeroservoelastic Interactions

Journal of Guidance, Control, and Dynamics, 2002
Introduction The adverse interactions occurring between the three main disciplines : unsteady aerodynamics, aeroelasticity and servo-controls are called aeroservoelastic interactions. These interactions can be described mathematically by a system of equations in a state space form.
Iulian Cotoi, Ruxandra M. Botez
openaire   +1 more source