Aerodynamics and aeroacoustics of wings and rotors via BEM - unsteady, transonic, and viscous effects

Abstract Recent developments on a general boundary integral formulation for the aerodynamic and aeroacoustic analyses of lifting bodies (e.g., wings and rotors) are reviewed. The emphasis is on recent numerical results, specifically on the effects of the unsteadiness, of the viscosity, and of the transonic nonlinearities. The boundary-element full-potential formulation for bodies in arbitrary motion is outlined along with the its extension to viscous/inviscid interaction. The effects of viscosity are taken into account through a coupled boundary-layer/full-potential technique similar to that used in the CFD community. Numerical results obtained with the present formulation are compared against numerical and experimental results available in literature. They include (i) aerodynamics and aeroacoustics of helicopter rotors in hover and forward flight in subsonic flows; (ii) transonic aerodynamics/acoustics results for steady potential flows around airfoils and hovering rotors, and (iii) viscous flows (subsonic and transonic) around airfoils.

[1]  Massimo Gennaretti,et al.  A Velocity Decomposition for Viscous Flows: Lighthill Equivalent-Source Method Revisited , 1997 .

[2]  L. Morino,et al.  Boundary integral equation for wave equation with moving boundary and applications to compressible potential aerodynamics of airplanes and helicopters , 1989 .

[3]  Anton J. Landgrebe,et al.  An Analytical and Experimental Investigation of Helicopter Rotor Hover Performance and Wake Geometry Characteristics , 1971 .

[4]  U. Iemma,et al.  Boundary integral equations and conservative dissipation schemes for full potential transonic flows , 1993, Computational Mechanics.

[5]  M. Lighthill.  On displacement thickness , 1958, Journal of Fluid Mechanics.

[6]  Massimo Gennaretti,et al.  Recent Developments on a BEM for Aerodynamics and Aeroacoustics of Rotors , 1995 .

[7]  Umberto Iemma,et al.  STEADY TWO-DIMENSIONAL TRANSONIC ANALYSIS USING A BOUNDARY INTEGRAL EQUATION METHOD , 1997 .

[8]  B. Thwaites,et al.  Approximate Calculation of the Laminar Boundary Layer , 1949 .

[9]  Luigi Morino,et al.  Boundary Integral Equations in Aerodynamics , 1993 .

[10]  Manuel D. Salas,et al.  Recent developments in transonic Euler flow over a circular cylinder , 1983 .

[11]  James D. Baeder,et al.  A Computational Study of the Aeroacoustics of Rotors in Hover , 1993 .

[12]  M. Costes,et al.  Aerodynamic and Acoustic Calculations of Transonic Nonlifting Hovering Rotors , 1996 .

[13]  Massimo Gennaretti,et al.  A Unified Boundary Integral Methodology for Aerodynamics and Aeroacoustics of Rotors , 1997 .

[14]  Jean-Claude Le Balleur.  Numerical Viscous-Inviscid Interaction in Steady and Unsteady Flows , 1984 .