03.1 - Aerodynamics – CFD Methods and Validation
NUMERICAL ANALYSIS OF GENERALIZED AERODYNAMIC FORCES CONSIDERING LAMINAR-TURBULENT TRANSITION ON A NLF WING
C. Sebastia Saez¹, J. Martin Ferres¹, M. Hornung¹; ¹Technical University of Munich, Germany
The wing’s dynamic aeroelastic stability analysis, referred to as flutter analysis, typically involves potential-rnflow-theory-based methods to model unsteady aerodynamics, which do not consider viscous or non-linearrneffects. Modern sailplane wings with Natural-Laminar-Flow (NLF) airfoils present significant chordwise runs ofrnlaminar boundary layer. Assuming an inviscid or completely turbulent flow over the wing chord would result inrncompletely wrong predictions of the unsteady aerodynamic characteristics of the wing and hence an inaccuraternprediction of the dynamic aeroelastic behavior.rnThis study presents a coupled FE beam model of a sailplane with a CFD model to calculate the GeneralizedrnAerodynamic Forces (GAF). The influence of transition on the unsteady aerodynamic response of a modernrnsailplane’s NLF wing is investigated numerically with the Gamma-Transition Model. The GAF are compared tornthe results obtained with the fully turbulent Spalart-Allmaras (SA) model.