Papers Published

  1. Romanowski, Michael C. and Dowell, Earl H., Using eigenmodes to form an efficient Euler based unsteady aerodynamics analysis, American Society of Mechanical Engineers, Aerospace Division (Publication) AD, vol. 44 (1994), pp. 147 - 160 .
    (last updated on 2007/04/10)

    Abstract:
    Fluid eigenmodes are used to created an efficient unsteady aerodynamics analysis for a 2D isolated airfoil immersed in a compressible flow field. For the first time, the eigenmodes are used to transform the large set of coupled, primitive variable (density, velocity, etc) equations, obtained from a time marching finite difference approximation of the Euler equations, into a much smaller set of decoupled (modal) equations. These reduced order models are shown to accurately predict unsteady load histories for harmonically pitching and plunging motions, as well as for step changes in angle of attack.

    Keywords:
    Unsteady flow;Eigenvalues and eigenfunctions;Airfoils;Compressible flow;Approximation theory;Finite difference method;Aerodynamic loads;Damping;