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You searched for +publisher:"Georgia Tech" +contributor:("Poulson, Jack"). Showing records 1 – 2 of 2 total matches.

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1. Wang, Xiaolin. A numerical study of vorticity-enhanced heat transfer.

Degree: PhD, Mathematics, 2014, Georgia Tech

In this work, we have numerically studied the effect of the vorticity on the enhancement of heat transfer in a channel flow. In the first part of the work, we focus on the investigation of a channel flow with a vortex street as the incoming flow. We propose a model to simulate the fluid dynamics. We find that the flow exhibits different properties depending on the value of four dimensionless parameters. In particularly, we can classify the flows into two types, active and passive vibration, based on the sign of the incoming vortices. In the second part of the work, we discuss the heat transfer process due to the flows just described and investigate how the vorticity in the flow improves the efficiency of the heat transfer. The temperature shows different characteristics corresponding to the active and passive vibration cases. In active vibration cases, the vortex blob improves the heat transfer by disrupting the thermal boundary layer and preventing the decay of the wall temperature gradient throughout the channel, and by enhancing the forced convection to cool down the wall temperature. The heat transxfer performance is directly related to the strength of the vortex blobs and the background flow. In passive vibration cases, the corresponding heat transfer process is complicated and varies dramatically as the flow changes its properties. We also studied the effect of thermal parameters on heat transfer performance. Finally, we propose a more realistic optimization problem which is to minimize the maximum temperature of the solids with a given input energy. We find that the best heat transfer performance is obtained in the active vibration case with zero background flow. Advisors/Committee Members: Zhou, Haomin (advisor), Silas, Alben (advisor), Liu, Yingjie (committee member), Chow, Edmond (committee member), Poulson, Jack (committee member).

Subjects/Keywords: Vorticity; Heat transfer; Enhancement

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APA (6th Edition):

Wang, X. (2014). A numerical study of vorticity-enhanced heat transfer. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/54017

Chicago Manual of Style (16th Edition):

Wang, Xiaolin. “A numerical study of vorticity-enhanced heat transfer.” 2014. Doctoral Dissertation, Georgia Tech. Accessed October 15, 2019. http://hdl.handle.net/1853/54017.

MLA Handbook (7th Edition):

Wang, Xiaolin. “A numerical study of vorticity-enhanced heat transfer.” 2014. Web. 15 Oct 2019.

Vancouver:

Wang X. A numerical study of vorticity-enhanced heat transfer. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2019 Oct 15]. Available from: http://hdl.handle.net/1853/54017.

Council of Science Editors:

Wang X. A numerical study of vorticity-enhanced heat transfer. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/54017

2. Turnes, Christopher Kowalczyk. Efficient solutions to Toeplitz-structured linear systems for signal processing.

Degree: PhD, Electrical and Computer Engineering, 2014, Georgia Tech

This research develops efficient solution methods for linear systems with scalar and multi-level Toeplitz structure. Toeplitz systems are common in one-dimensional signal-processing applications, and typically correspond to temporal- or spatial-invariance in the underlying physical phenomenon. Over time, a number of algorithms have been developed to solve these systems economically by exploiting their structure. These developments began with the Levinson-Durbin recursion, a classical fast method for solving Toeplitz systems that has become a standard algorithm in signal processing. Over time, more advanced routines known as superfast algorithms were introduced that are capable of solving Toeplitz systems with even lower asymptotic complexity. For multi-dimensional signals, temporally- and spatially-invariant systems have linear-algebraic descriptions characterized by multi-level Toeplitz matrices, which exhibit Toeplitz structure on multiple levels. These matrices lack the same algebraic properties and structural simplicity of their scalar analogs. As a result, it has proven exceedingly difficult to extend the existing scalar Toeplitz algorithms for their treatment. This research presents algorithms to solve scalar and two-level Toeplitz systems through a constructive approach, using methods devised for specialized cases to build more general solution methods. These methods extend known scalar Toeplitz inversion results to more general scalar least-squares problems and to multi-level Toeplitz problems. The resulting algorithms have the potential to provide substantial computational gains for a large class of problems in signal processing, such as image deconvolution, non-uniform resampling, and the reconstruction of spatial volumes from non-uniform Fourier samples. Advisors/Committee Members: McClellan, James (advisor), Romberg, Justin (committee member), Barnes, Christopher (committee member), Hayes, Monson H. (committee member), Poulson, Jack (committee member), Balcan, Doru (committee member).

Subjects/Keywords: Multi-level toeplitz; Superfast algorithms; Structured linear algebra; Toeplitz inversion; Digital resampling; Non-uniform FFTs; 3-D MRI; Signal processing; Toeplitz matrices; Algorithms

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Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Turnes, C. K. (2014). Efficient solutions to Toeplitz-structured linear systems for signal processing. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/51878

Chicago Manual of Style (16th Edition):

Turnes, Christopher Kowalczyk. “Efficient solutions to Toeplitz-structured linear systems for signal processing.” 2014. Doctoral Dissertation, Georgia Tech. Accessed October 15, 2019. http://hdl.handle.net/1853/51878.

MLA Handbook (7th Edition):

Turnes, Christopher Kowalczyk. “Efficient solutions to Toeplitz-structured linear systems for signal processing.” 2014. Web. 15 Oct 2019.

Vancouver:

Turnes CK. Efficient solutions to Toeplitz-structured linear systems for signal processing. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2019 Oct 15]. Available from: http://hdl.handle.net/1853/51878.

Council of Science Editors:

Turnes CK. Efficient solutions to Toeplitz-structured linear systems for signal processing. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/51878

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