Show simple item record

dc.contributor.authorRaben, Samuel Gilloolyen_US
dc.date.accessioned2015-04-25T08:04:45Z
dc.date.available2015-04-25T08:04:45Z
dc.date.issued2013-09-10en_US
dc.identifier.othervt_gsexam:1630en_US
dc.identifier.urihttp://hdl.handle.net/10919/51818
dc.description.abstractTime varying flow structures are involved in a large percentage of fluid flows although there is still much unknown regarding their behavior. With the development of high spatiotemporal resolution measurement systems it is becoming more feasible to measure these complex flow structures, which in turn will lead to a better understanding of their impact. One method that has been developed for studying these flow structures is finite time Lyapunov exponents (FTLEs). These exponents can reveal regions in the fluid, referred to as Lagragnian coherent structures (LCSs), where fluid elements diverge or attract. Better knowledge of how these time varying structures behave can greatly impact a wide range of applications, from aircraft design and performance, to an improved understanding of mixing and transport in the human body. This work provides the development of new methodologies for measuring and studying three-dimensional time varying structures. Provided herein is a method to improve replacement of erroneous measurements in particle image velocimetry data, which leads to increased accuracy in the data. Also, a method for directly measuring the finite time Lyapunov exponents from particle images is developed, as well as an experimental demonstration in a three-dimensional flow field. This method takes advantage of the information inherently contained in these images to improve accuracy and reduce computational requirements. Lastly, this work provides an in depth look at the flow field for developing wall jets across a wide range of Reynolds numbers investigating the mechanisms that contribute to their development.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectParticle Image Velocimetryen_US
dc.subjectProper Orthogonal Decompositionen_US
dc.subjectFinite Time Lyapunov Exponentsen_US
dc.subjectLagrangian Coherent Structuresen_US
dc.titleDetermination of Three Dimensional Time Varying Flow Structuresen_US
dc.typeDissertationen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMechanical Engineeringen_US
dc.contributor.committeechairVlachos, Pavlos P.en_US
dc.contributor.committeechairRoss, Shane D.en_US
dc.contributor.committeememberStremler, Mark A.en_US
dc.contributor.committeememberPaul, Mark R.en_US
dc.contributor.committeememberBall, Kenneth S.en_US


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record