Samara-Seed Aerodynamics

Limacher, Eric

Samara-Seed Aerodynamics

atmire.migration.oldid	2897
dc.contributor.advisor	Rival, David Emory
dc.contributor.advisor	Wood, David
dc.contributor.author	Limacher, Eric
dc.date.accessioned	2015-01-26T17:05:21Z
dc.date.available	2015-02-23T08:00:39Z
dc.date.issued	2015-01-26
dc.date.submitted	2015	en
dc.description.abstract	Samaras are tree seeds that spontaneously rotate about the vertical axis as they fall. This flight pattern, referred to as autorotation, generates aerodynamic lift to slow a samara’s descent. In this thesis, samara flight is studied in steady-state and during a transient gust-response. In steady-state autorotation, the circulation and topology of the flow over samaras are investigated using particle image velocimetry (PIV). The stable attachment of leading-edge vortices - a lift-enhancing mechanism - is shown to depend on tip speed ratio. Leading-edge circulation, however, is insensitive to changes in tip speed ratio. The dynamic gust-response of samaras is studied using high-speed video. A linear dynamic model is developed based on momentum theory, and is shown to adequately predict the post-gust acceleration of an Acer negundo samara. The model predicts that axial gusts of sufficient strength or frequency can disrupt autorotation by compromising pitch-stability.	en_US
dc.identifier.citation	Limacher, E. (2015). Samara-Seed Aerodynamics (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27706	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/27706
dc.identifier.uri	http://hdl.handle.net/11023/2028
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Ecology
dc.subject	Fluid and Plasma
dc.subject	Engineering--Mechanical
dc.subject.classification	samara	en_US
dc.subject.classification	Leading-edge vortex	en_US
dc.subject.classification	autorotation	en_US
dc.title	Samara-Seed Aerodynamics
dc.type	master thesis
thesis.degree.discipline	Mechanical and Manufacturing Engineering
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.item.requestcopy	true