Effect of Acoustic Slat Modifications on Aerodynamic Properties of High-Lift Systems

Abstract

The objective of this document is the determination of the effect of brush-like devices at the slat trailing edge on the aerodynamic properties of a high-lift system. Such devices show promising results with respect to significant noise reduction. But, up to now the effect of these devices on the aerodynamic properties have not been considered. This study shows that all investigated cylindrical brush hairs affect the aerodynamic properties of a high-lift system adversely since the influenced slat wake reduces the aerodynamic performance. But, cutting many small gaps into the slat trailing edge, resulting in brushes of rectanular cross section, the effect on the global coefficients is minor, sometimes slightly favourable.