A Numerical Study on the Unsteady Aerodynamic Characteristics of Thick Aerofoils with Wavy Leading Edges

Abstract

Numerical simulations are performed over a Wavy Leading Edge (WLE) aerofoil using a
NACA0021 section with a WLE wavelength of 11% and an WLE amplitude of 3% of the
mean chord. The results obtained match the experimental data available in literature with
better accuracy than previous publications. Nevertheless it is observed that, in contrast
to what has been shown in previous literature the flow over a WLE is not periodic in
every wavelength when the angle of attack is very high. Instead Laminar Separation
Bubbles (LSB) appear at every second trough that eventually transition to turbulence
and enables partial reattachment for a small percentage of the chord length. On the other
troughs however, the flow suffers from laminar separation at the leading edge. It is also
found out that the regions with the LSBs give an increased aerodynamic efficiency with
respect the other trough sections of roughly 6% for the tested WLE parameters at angle of attack of 20 ? . Furthermore the WLE are able to debilitate the strength of the vortex
shedding mechanism because of the heterogeneity that promote to the flow across the
span.

More information

Identifiers

Catalogue record

Export record