東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Kinematics of vortices in turbulent ...

Chakraborty, Pinaki.

Linked to FindBook

Google Book

Amazon

博客來

Kinematics of vortices in turbulent flows.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Kinematics of vortices in turbulent flows./
Author:	Chakraborty, Pinaki.
Description:	124 p.
Notes:	Advisers: Ronald J. Adrian; S. Balachandar.
Contained By:	Dissertation Abstracts International67-07B.
Subject:	Applied Mechanics. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3223556
ISBN:	9780542773457

Kinematics of vortices in turbulent flows.
Chakraborty, Pinaki.

Kinematics of vortices in turbulent flows. - 124 p.

Advisers: Ronald J. Adrian; S. Balachandar.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.

We analyze the currently popular vortex-identification criteria that are based on point-wise analysis of the velocity gradient tensor. We introduce a new measure of spiraling compactness of material orbits in vortices and use this measure to propose a new local vortex-identification criterion and requirements for a vortex core. Using both zero and non-zero thresholds for the identification parameter, we explore analytically the interrelationships between the different criteria. These interrelationships provide a new interpretation of the various criteria in terms of the local flow kinematics. We study three canonical turbulent flow examples and observe that all the criteria, given the proposed usage of threshold, result in remarkably similar-looking vortical structures. We offer a unified interpretation based on local flow kinematics for the conditions under which similarity or differences can be expected in the vortical structures educed using the different criteria.

ISBN: 9780542773457Subjects--Topical Terms:

1018410
Applied Mechanics.

Kinematics of vortices in turbulent flows.
LDR:03267nam 2200301 a 45 001 967523
005 20110915
008 110915s2006 eng d
020 $a 9780542773457
035 $a (UMI)AAI3223556
035 $a AAI3223556
040 $a UMI $c UMI
100 1 $a Chakraborty, Pinaki. $3 1291393
245 1 0 $a Kinematics of vortices in turbulent flows.
300 $a 124 p.
500 $a Advisers: Ronald J. Adrian; S. Balachandar.
500 $a Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3884.
502 $a Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.
520 $a We analyze the currently popular vortex-identification criteria that are based on point-wise analysis of the velocity gradient tensor. We introduce a new measure of spiraling compactness of material orbits in vortices and use this measure to propose a new local vortex-identification criterion and requirements for a vortex core. Using both zero and non-zero thresholds for the identification parameter, we explore analytically the interrelationships between the different criteria. These interrelationships provide a new interpretation of the various criteria in terms of the local flow kinematics. We study three canonical turbulent flow examples and observe that all the criteria, given the proposed usage of threshold, result in remarkably similar-looking vortical structures. We offer a unified interpretation based on local flow kinematics for the conditions under which similarity or differences can be expected in the vortical structures educed using the different criteria.
520 $a The commonly used local vortex-identification criteria are formulated based on some characteristics of a vortex that is isolated from any effects of other vortical and strain fields. Nevertheless, these criteria have been frequently used for extracting vortical structures in complex flows in which the vortices are curved (self-interaction) and/or are in close proximity to each other (mutual-interaction). We study the effects of such interactions on the validity of the usage of local criteria for extracting the vortices. Our study is a posteriori in nature: we construct flow fields based on vortex interactions and then use vortex criteria to extract the constituent vortices. We find that self-interaction does not drastically affect vortex identification, whereas mutual interaction may significantly affect the extracted vortex structure. We propose a simple model that may be used to predict the effects of mutual interaction on the vortex structure extracted by the different vortex criteria.
520 $a The concept of a hierarchy of vortices in the physical space of turbulent flows is commonly extended to Fourier space. Through an analysis of Gaussian vortices, we explore the concept a vortex in Fourier space in terms of local flow kinematics. We find that interpreting a hierarchy of vortices in Fourier space may lead to incorrect results.
590 $a School code: 0090.
650 4 $a Applied Mechanics. $3 1018410
690 $a 0346
710 2 0 $a University of Illinois at Urbana-Champaign. $3 626646
773 0 $t Dissertation Abstracts International $g 67-07B.
790 $a 0090
790 1 0 $a Adrian, Ronald J., $e advisor
790 1 0 $a Balachandar, S., $e advisor
791 $a Ph.D.
792 $a 2006
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3223556