Gust Response for Flexibly Suspended High-Aspect Ratio Wings

Abstract

A theoretical aeroelastic study for a flexibly suspended high-aspect ratio wing aeroelastic model excited by gust loads is presented along with a companion wind-tunnel test. A flexible support system at the wing root has been constructed to simulate a rigid body mode. Structural equations of motion based on a nonlinear beam theory are combined with the ONERA aerodynamic model. Also, a dynamic perturbation analysis about a nonlinear static equilibrium is used to determine the small perturbation flutter boundary and structural natural frequencies. The effects of the flexible support system (bi-beam system) on the wing structural dynamics, the static aeroelastic displacement at root, nonlinear flutter, and gust response to a harmonic or a frequency sweep excitation are discussed. Also the effect of gust distribution along the span on the response is described based upon computations. The fair to good quantitative agreement between theory and experiment demonstrates that the present analysis method has reasonable accuracy.

Experimental Aeroelastic Models Design and Wind Tunnel Testing for Correlation with New Theory

“…They include: (1) A high aspect ratio wing model. Several correlation studies for flutter and limit cycle oscillation (LCO) [1], limit cycle hysteresis response [2], gust response for clamped and flexibly suspended models [3,4] and Flutter/LCO suppression [5] were performed. (2) Wing like plate models, delta wing-store, flapping flag, yawed plate and folding wing.…”

“…(3) Airfoil section with control surface freeplay. The wing tunnel tests were used to evaluate new approaches for the freeplay nonlinear and gust responses including Duke computational codes using the Peter's finite state airload aerodynamic theory, harmonic balance method, and the time marching integration based on state space equations [20][21][22][23][24] and the ZAERO code [25] based on the computational fluid dynamic (CFD) theory conducted by ZONA Technology, Inc. (4) All-movable tail with freeplay model at the root [26,27] to similar horizontal tail in the actuating mechanism freeplay nonlinearity of aircraft. Based on this model a computational code has been developed and evaluated.…”

Transfer Function Method for the Nonlinear Flutter of a High-aspect-ratio Wing

“…Z Sotoudeh [6] developed aeroelastic analysis of a flexible UAV at high altitude, A set of computer programs specially designed for such UAVs can be used to obtain the results of aeroelastic analysis in a short period of time, which is convenient for the design of flexible UAVs. D Tang [7] combined the aeroelastic analysis of flexible wings with the wind Hole test, a theoretical aeroelastic model of aeroelastic model with flexible large aspect ratio airfoil under elastic load is introduced. MJ Patil et al [8,9] proposed the aeroelastic behavior of a complete aircraft model and the results obtained from the analysis of the overall flight dynamics.…”

Effects of a Free-to-Roll Fuselage on Wing Flutter: Theory and Experiment

“…These are suitable for studying computational and experimental correlation for linear and nonlinear aeroelastic response. In [10], an experimental high-aspect-ratio wing model with a root flexible suspension system has been studied. Comparing [9,10], there are different flutter/LCO trends and gust responses due to the different boundary conditions at the wing root.…”

“…In [10], an experimental high-aspect-ratio wing model with a root flexible suspension system has been studied. Comparing [9,10], there are different flutter/LCO trends and gust responses due to the different boundary conditions at the wing root. These different results are observed in the subsonic tunnel test as well as in the computational simulations.…”