mirage   mirage   mirage

Experiments on a low aspect ratio wing at low Reynolds numbers

DSpace/Manakin Repository

Show simple item record

dc.creator Morse, Daniel R.
dc.date.accessioned 2009-01-05T18:06:00Z
dc.date.available 2009-01-05T18:06:00Z
dc.date.copyright 2008-11-20
dc.date.issued 2008-11-20
dc.identifier.uri http://hdl.handle.net/1957/10009
dc.description Graduation date: 2009 en_US
dc.description.abstract At the start of the 21st century much of the focus of aircraft design has been turned to unmanned aerial vehicles (UAVs) which generally operate at much lower speeds in higher risk areas than manned aircraft. One subset of UAVs are Micro Air Vehicles (MAVs) which usually are no larger than 20cm and rely on non-traditional shapes to generate lift at very low velocities. This purpose of this work is to describe, in detail with experimental methods, the flow field around a low aspect ratio wing operating at low Reynolds numbers and at high angles of attack. Quantitative measurements are obtained by Three Component Time Resolved Particle Image Velocimetry (3C TR PIV) which describe the mean and turbulent flow field. This research focuses on the leading edge separation zone and the vortex shedding process which occurs at the leading edge. Streamwise wing tip vortices which dominate the lift characteristics are described with flow visualization and 3C TR PIV measurements. Turbulent Kinetic Energy (TKE) is described at the leading edge over several angles of attack. Turbulent Reynolds stresses in all three directions are described over the wing span and several Reynolds numbers. Two primary cyclic processes are observed within the flow field; one low frequency oscillation in the separated region and one high frequency event associated with leading edge vortex formation and convection. Two length scales are proposed and are shown to match well with each other, one based on leading edge vortex shedding frequency and convective velocity and the other based on mean vortex separation distance. A new method of rendering velocity frequency content over large data sets is proposed and used to illustrate the different frequencies observed at the leading edge. en_US
dc.language.iso en_US en_US
dc.subject Time Resolved en_US
dc.subject PIV en_US
dc.subject Low Reynolds en_US
dc.subject Low Aspect Ratio en_US
dc.subject Wing en_US
dc.subject Vortex Shedding en_US
dc.subject.lcsh Airplanes -- Wings -- Fluid dynamics en_US
dc.subject.lcsh Aerofoils -- Aerodynamics en_US
dc.subject.lcsh Vortex shedding en_US
dc.subject.lcsh Reynolds number en_US
dc.subject.lcsh Flow visualization en_US
dc.title Experiments on a low aspect ratio wing at low Reynolds numbers en_US
dc.type Thesis en_US
dc.degree.name Doctor of Philosophy (Ph. D.) in Mechanical Engineering en_US
dc.degree.level Doctoral en_US
dc.degree.discipline Engineering en_US
dc.degree.grantor Oregon State University en_US
dc.contributor.committeemember Narayanan, Vinod
dc.contributor.committeemember Apte, Sourabh
dc.contributor.committeemember Zhang, Eugene
dc.contributor.committeemember Higdon, Robert


The following license files are associated with this item:

This item appears in the following Collection(s)

Show simple item record

Search ScholarsArchive@OSU


Advanced Search

Browse

My Account

Statistics