The Doublet-Lattice Method (DLM) based on the Prandtl-Glauert transformation for compressible subsonic flow outlined in Albano and Rodden and ZONA51 outlined in Liu et al. The structural characteristics of the clean wing (defined here as the JSM_ c model) and the wing-pylon-nacelle-engine model (defined here as the JSM_ enp model) are analyzed using NX Nastran Finite Element Method (FEM). for operations at both subsonic and low supersonic flight regimes. on the aeroelastic analysis of a wing-pylon-nacelle configuration based on the geometry of the JAXA Standard Wing Model (JSM) defined for the NASA high lift prediction workshop outlined in Ref. The present study stems from the authors’ earlier work, Yu et al. investigated the aeroelastic behaviour of a wing with a bypass ratio engine and high-lift devices using a reduced-order model where the results indicated heave instabilities can occur at strongly negative angles of attack. analyzed an aeroelastic model of the wing/engine system of a large commercial aircraft by considering the effect of engine inertial force and thrust, static aeroelastic deformation of the wing structure, and load distributions on the aeroelastic response. computed transonic flutter of a wing-pylon-nacelle configuration using a thin-layer approximation compressible Navier–Stokes flow model to show the effect of viscosity on the flow on its flutter boundary. investigated the flutter behaviour of a binary wing-with-engine nacelle system using the inviscid incompressible flow model for a variety of systematic parameter variations. Wing-mounted engine nacelle treated as structural nonlinearity on the flutter and LCO characteristics of the configuration are worthy of an investigation and have been investigated in a number of studies. have shown that the effect of external stores on the flutter boundaries for F16A fighter aircraft with missiles fitted on the wings can be significant for both typical LCO and non-typical LCO cases. For example, the flight test data of Laurenson and Trn and the numerical simulations of Chen et al. Among the various types of structural nonlinearities, an external store could cause a significant effect on the aeroelastic responses of an aircraft wing. , Laurenson and Trn, Lee, Yang and Zhao and Lee and Tron. Most instants of flutter or limit cycle oscillation (LCO) encountered in aircraft flight can be attributed to the presence of multiple structural nonlinearities present in control surface free-plays, underwing or wingtip attached external stores, hysteresis, and cubic stiffness of materials as outlined in Woolston et al. For these reasons, flutter characteristics of aircraft structures in fluid flow are analyzed for mitigating the consequences of flutter. Thereafter, the linearized aeroelastic equations are resolved using the continuation method with adaptive step size, the results of which are matched with those obtained from the traditional p- k method to emphasize that the continuation method exhibits a distinct advantage in achieving better accuracy in estimating the flutter speed and identifying the “mode switching” phenomenon.įlutter is an oscillatory motion resulting from the interaction between aerodynamic forces and structural vibrations which can result in a loss of control or serious damage to the aircraft. The Rational Function Approximation (RFA) method is then utilized for the state-space formulation of the system equations, appended with the continuation method for flutter prediction. The aerodynamic forces relating to different reduced frequencies are assessed using the Doublet Lattice Method (DLM) in the subsonic flow regime and supersonic lifting surface theory relying on the unsteady linearized small-disturbance potential flow model in the low supersonic flow regime. Idealizing the pylon and nacelle as a point mass, the computed effects of a standard structural analysis of the wing together with the pylon and nacelle are compared with those of a clean wing to build a reduced-order model for analysis. In this study, the aeroelastic response of a wing-pylon-nacelle system in subsonic and low supersonic flow regimes is analyzed using the continuation method in conjunction with an adaptive step size control algorithm.
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