Effect of large distributed roughness near an airfoil leading edge on boundary layer development and transition

"An experimental study of the effects of large distributed roughness located near the leading-edge of an airfoil has been performed to determine the effect on boundary-layer development and transition. Boundary-layer measurements were carried out on a two-dimensional NACA 0012 airfoil with a 21"" chord. The distributed roughness used was in the form of densely packed large hemispherical elements applied to the leading-edge region of the airfoil section. The size of the distributed roughness was greater than or on the order of the laminar boundary-layer thickness. The roughness used is of the type and density observed to occur during the initial glaze ice accretion process. Detailed boundary-layer measurements were obtained through the use of hot-wire anemometry at Reynolds numbers of 0.75 $\times$ 10$\sp6$, 1.25 $\times$ 10$\sp6$, and 2.25 $\times$ 10$\sp6$. These measurements included mean and fluctuating velocity, turbulence intensity, flowfield intermittency, frequency content, and associated integral parameters. Both the clean model and roughness induced transitional boundary-layers were studied in great detail."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Kerho, Michael Fort

Contributors dc:contributor

• Bragg, Michael B.

• Engineering, Aerospace

Statement dc:rights

• Copyright 1995 Kerho, Michael Fort

Language dc:language

eng

Identifier

AAI9522129
(UMI)AAI9522129

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21430