R.G.A. Silva, O.A.F. Mello, J.L.F. Azevedo, P.C. Chen, D.D. Liu

The work presents a study of correction techniques to compute unsteady transonic pressure distributions and aeroelastic stability in this flow regime. The methodologies herein investigated are based on corrections of pressure distributions by the weighting of the lifting surface self-induced downwash, resulting from aeroelastic structural displacements or prescribed motions. A number approaches were investigated. An investigation into the linear/nonlinear behavior of unsteady transonic flows was also conducted. It was concluded from such investigation that unsteady transonic flows present a linear behavior with respect to small aeroelastic structural displacements around a steady nonlinear mean flow. Such behavior is the basis for further development of downwash correction methods. The correction of pressure distributions through the weighting of the lifting surface self-induced downwash is also known as downwash weighting method. This method has been enhanced leading to a new downwash correction technique. This extended downwash correction method led to a rational formulation named as "successive kernel expansion method" (SKEM), also named as ZTAW method, as it is implemented in ZAERO software system. The unsteady pressures and aeroelastic stability boundaries computations using such method led to good agreement with experimental measurements. This procedure is a rapid form to compute the transonic flutter speed boundaries, compared to computational aeroelasticity and experimental techniques.

International Forum on Aeroelasticity and Structural Dynamics, 2005, München

Conference Paper

englisch

21,0 x 29,7 cm, 21 Seiten

DGLR-Bericht, 2005, 2005-04, International Forum on Aeroelasticity and Structural Dynamics 2005; S.1-21; 2005; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

transonic flows, flutter

Bibliothek

2005