Sat, 26 Jul 2008 07:27:42 BST CiteULike: l-alex's pod http://www.citeulike.org/user/l-alex/tag/pod CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/l-alex/article/2322544 <i>Physics of Fluids, Vol. 10, No. 7. (1998), pp. 1685-1699.</i><br /><br />  Proper orthogonal decomposition and low-dimensional models for driven cavity flows W Cazemier RWCP Verstappen AEP Veldman Physics of Fluids, Vol. 10, No. 7. (1998), pp. 1685-1699. 2008-02-02T09:10:51-00:00 1998 Physics of Fluids 10 7 1685 1699 AIP cavity pod http://www.citeulike.org/user/l-alex/article/1386650 <i>Theoretical and Computational Fluid Dynamics, Vol. 19, No. 2. (1 May 2005), pp. 115-125.</i><br /><br />The topology of large scale structures in a turbulent boundary layer is investigated numerically. Spatial characteristics of the large scale structure are presented through an original method, proper orthogonal decomposition (POD) of the three-dimensional vorticity fields. The DNS results, obtained by Tiselj et al. [23] for a fully developed turbulent flow in a flume, are used in the present work to analyze coherent structures with the proposed methodology. In contrast to the reconstruction methods that use instantaneous flow quantities, this approach utilizes the whole dataset of the numerical simulation. The analysis uses one thousand 3D vorticity fields from 50000 time steps of the simulation for the Reynolds number of 2600 (the turbulent Reynolds number Re*=171). The computational domain is 2146×171×537 wall units and the grid resolution is 128×65×72 points (in streamwise, wall-normal and spanwise directions, respectively). Experimental results obtained by using particle image velocimetry (PIV) in a fully developed turbulent boundary layer in a flume, which were analyzed with the same statistical characterization method, are in agreement with the DNS analysis: the dominant vortical structure appears to have a longitudinal streamwise orientation, an inclination angle of about 8°, streamwise length of several hundred wall units, and a distance between the neighboring structures of about 100 wall units in the spanwise direction. Spatial characterization of the numerically simulated vorticity fields of a flow in a flume Alex Liberzon Roi Gurka Iztok Tiselj Gad Hetsroni doi:10.1007/s00162-004-0156-y Theoretical and Computational Fluid Dynamics, Vol. 19, No. 2. (1 May 2005), pp. 115-125. 2007-06-13T07:08:27-00:00 2005 Theoretical and Computational Fluid Dynamics 19 2 115 125 coherent-structures pod http://www.citeulike.org/user/l-alex/article/1386649 <i>International Journal of Heat and Fluid Flow, Vol. 26, No. 2. (April 2005), pp. 276-288.</i><br /><br />The approach of proper orthogonal decomposition (POD) has been extensively adopted for fluid dynamics in fixed geometries. This technique is examined here for fluid flow with moving boundaries; in the context of cavitating and phase change flows, and fluid-membrane interaction. The purpose is to assess the capability of POD in extracting the salient features and offering a compact representation to the CFD solutions associated with boundary movement. The cavitating flow simulations are investigated to distill the effect of turbulence modeling, between the Launder-Spalding and a filter-based turbulence models. The lower-order eigenmodes of the flow field, for both turbulence models, show different flow structures and global parameters between higher and lower cavitation numbers. The effect of multi-timescales produced by the filter-based turbulence model is discerned by POD analysis. For 3-D, membrane wing flows, very few POD modes seem sufficient for accurate representation of the velocity field. However, reduced-order analysis of the aerodynamic performance, which is strongly dictated by pressure, may be coarsened by moving membrane dynamics. The flow with fusion is further considered for its solid-liquid phase front propagation. While few modes can sufficiently construct the flow field for the later interval of the flow, a larger number of POD modes are required to provide the flow scales for the initial part of the phase change process. Reduced-order description of fluid flow with moving boundaries by proper orthogonal decomposition Yogen Utturkar Baoning Zhang Wei Shyy International Journal of Heat and Fluid Flow, Vol. 26, No. 2. (April 2005), pp. 276-288. 2007-06-13T07:07:58-00:00 2005 International Journal of Heat and Fluid Flow 26 2 276 288 moving-boundaries pod http://www.citeulike.org/user/l-alex/article/248820 <i>Nonlinear Dynamics, Vol. 41, No. 1-3. (August 2005), pp. 275-307.</i> Low-Dimensional Modelling of Turbulence Using the Proper Orthogonal Decomposition: A Tutorial Troy Smith Jeff Moehlis Philip Holmes doi:10.1007/s11071-005-2823-y Nonlinear Dynamics, Vol. 41, No. 1-3. (August 2005), pp. 275-307. 2005-07-07T12:30:07-00:00 2005 Nonlinear Dynamics 0924-090X 41 1-3 275 307 Kluwer Academic Publishers coherent-structures pod http://www.citeulike.org/user/l-alex/article/634878 <i>Alex Liberzon, Roi Gurka, Iztok Tiselj, Gad Hetsroni, Spatial, Vol. 19, No. s2. (2005), pp. 115-125.</i> Spatial characterization of the numerically simulated vorticity fields of a flow in a flume A Liberzon R Gurka I Tiselj G Hetsroni Alex Liberzon, Roi Gurka, Iztok Tiselj, Gad Hetsroni, Spatial, Vol. 19, No. s2. (2005), pp. 115-125. 2006-05-14T21:47:54-00:00 2005 Alex Liberzon, Roi Gurka, Iztok Tiselj, Gad Hetsroni, Spatial 19 s2 115 125 coherent-structures flume pod vorticity http://www.citeulike.org/user/l-alex/article/634877 <i>International Journal of Heat and Fluid Flow, Vol. 27, No. 3. (June 2006), pp. 416-423.</i><br /><br />We present a method to identify large scale coherent structures, in turbulent flows, and characterize them. The method is based on the linear combination of the proper orthogonal decomposition (POD) modes of vorticity. Spanwise vorticity is derived from the two-dimensional and two-component velocity fields measured by means of particle image velocimetry (PIV) in the streamwise-wall normal plane of a fully developed turbulent boundary layer in a flume. The identification method makes use of the whole data set simultaneously, through the two-point correlation tensor, providing a statistical description of the dominant coherent motions in a turbulent boundary layer. The identified pattern resembles an elongated, quasi-streamwise, vortical structure with streamwise length equal to the water height in the flume and inclined upwards in the streamwise-wall normal plane at angle of approximately 8[deg]. POD of vorticity fields: A method for spatial characterization of coherent structures Roi Gurka Alexander Liberzon Gad Hetsroni doi:10.1016/j.ijheatfluidflow.2006.01.001 International Journal of Heat and Fluid Flow, Vol. 27, No. 3. (June 2006), pp. 416-423. 2006-05-14T21:33:47-00:00 2006 International Journal of Heat and Fluid Flow 27 3 416 423 coherent-structures pod http://www.citeulike.org/user/l-alex/article/592380 <i>Vol. 12 (1970)</i> Stochastic Tools in Turbulence JL Lumley Vol. 12 (1970) 2006-04-20T15:40:14-00:00 1970 12 Academic Press pod turbulence http://www.citeulike.org/user/l-alex/article/592295 <i>Physical Rev, Vol. A 36 (1987), pp. 340-346.</i> Singular-Value Decomposition and Embedding Dimension AI Mees PE Rapp LS Jennings Physical Rev, Vol. A 36 (1987), pp. 340-346. 2006-04-20T15:40:10-00:00 1987 Physical Rev A 36 340 346 image-processing pod http://www.citeulike.org/user/l-alex/article/592278 <i>J. Fluid Mech., Vol. 192 (1988)</i> The Dynamics of Coherent Structures in the Wall Region of a Turbulent Boundary Layer N Aubry P Holmes JL Lumley E Stone J. Fluid Mech., Vol. 192 (1988) 2006-04-20T15:40:10-00:00 1988 J. Fluid Mech. 192 coherent-structures pod http://www.citeulike.org/user/l-alex/article/592275 <i>Physica, Vol. D, No. 37. (1989)</i> Chaotic dynamics of coherent structures L Sirovich Physica, Vol. D, No. 37. (1989) 2006-04-20T15:40:09-00:00 1989 Physica D 37 coherent-structures pod