FLUTTER SPEED LIMITS OF SUBSONIC WINGS

Flutter is a phenomenon resulting from the interaction between aerodynamic and structural dynamic forces may lead to destructive instability. The on an oscillating airfoil combination of two independent degrees freedom have been determined. problem resolves itself into solution certain definite integrals, which identified as Theodorsen functions. theory, being based potential flow Kutta condition, fundamentally equivalent conventional wing-ection theory relating steady case. mechanism instability has analyzed in detail. An exact solution, involving adoption simple form expressed by means auxiliary parameter K. use finite element modeling technique unsteady with V-G method for flutter speed prediction was used fixed rectangular tapered wing determine boundaries. To build Ansys 5.4 program extract values were substituted Matlab designed then predicted various effects speed. gave us approximately identical results referred researches. following design parameters investigated skin shell thickness, material properties, cross section area beams, changing altitude. Results these calculations indicate that mode shape variation plays significant role determination boundary.