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A SUBGRID-SCALE MODEL FOR LARGE-EDDY SIMULATION BASED ON THE PHYSICS OF INTERSCALE ENERGY TRANSFER IN TURBULENCE by Brian Wayne Anderson A Dissertation Presented to the FACULTY OF THE USC GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Ful llment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (AEROSPACE ENGINEERING) May 2012 Copyright 2012 Brian Wayne Anderson
|Title||A subgrid-scale model for large-eddy simulation based on the physics of interscale energy transfer in turbulence|
|Author||Anderson, Brian Wayne|
|Degree||Doctor of Philosophy|
|Degree program||Aerospace Engineering|
|School||Viterbi School of Engineering|
|Advisor (committee chair)||Domaradzki, Julian A.|
|Advisor (committee member)||
Blackwelder, Ron F.
Shiflett, Geoffrey R.
Wellford, Carter L.
Pottebaum, Tait S.
Wilcox, David C.
|Abstract||In large-eddy simulation (LES) various subgrid-scale models have been proposed, all of which attempt to account for the unknown effects of the unresolved scales of turbulence on the resolved flow-field. The scale-similarity model is one such model, which is formulated using a secondary filter applied to components of the resolved velocity and its products. The scale-similarity model is based on the assumption that the velocities associated with neighboring scales in the flow produce turbulent stresses that are similar in character. The model uses an expression that weights the scales just below the LES cutoff in its approximation of the stresses of the unresolved scales. It is well-known, however, that the similarity model fails to accurately predict some of the most fundamental quantities in turbulent flows, perhaps the most important being the global energy transfer and the associated subgrid-scale dissipation. In previous research, additional dissipative terms have been added to the similarity model to improve the model's performance. ❧ In the present research, considerations of interscale energy transfer have been used to identify the deficiencies of the energy transfer role of the similarity model, specifically its inadequate removal of terms contributing energy to the smallest scales and its duplication of terms producing effects in the largest scales. These considerations are then used in the development of a new model, which shows more favorable characteristics of energy transfer. In this approach, partial nonlinear terms are used to decompose the nonlinear transfer present in LES and to formulate an expression capable of removing small-scale production terms depositing energy near the LES cutoff. The proposed model is formulated in the same vein as the scale-similarity model, consisting of test-filtered velocities and their products, but the new interscale transfer model offers improvements in its predictions of mean flow quantities and the global energy flux from the resolved to subgrid scales. The current research demonstrates that by implementing this model in a posteriori LES testing of wall-bounded flows, improved LES predictions are possible without the need for additional terms to augment subgrid-scale energy dissipation.|
|Keyword||large-eddy; large-eddy simulation; les; subgrid; subgrid-scale; subgrid scale; subgrid-scale model; subgrid scale model; interscale energy transfer model;interscale-energy transfer; interscale transfer model; interscale energy transfer; interscale transfer; interscale energy; itm; scale-similarity model; similarity model; subgrid scale dissipation; subfilter scale; differential filter; discrete filter|
|Part of collection||University of Southern California dissertations and theses|
|Publisher (of the original version)||University of Southern California|
|Place of publication (of the original version)||Los Angeles, California|
|Publisher (of the digital version)||University of Southern California. Libraries|
|Provenance||Electronically uploaded by the author|
|Legacy record ID||usctheses-m|
|Rights||Anderson, Brian Wayne|
|Access conditions||The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the author, as the original true and official version of the work, but does not grant the reader permission to use the work if the desired use is covered by copyright. It is the author, as rights holder, who must provide use permission if such use is covered by copyright. The original signature page accompanying the original submission of the work to the USC Libraries is retained by the USC Libraries and a copy of it may be obtained by authorized requesters contacting the repository e-mail address given.|
|Repository name||University of Southern California Digital Library|
|Repository address||USC Digital Library, University of Southern California, University Park Campus MC 7002, 106 University Village, Los Angeles, California 90089-7002, USA|
|Full text||A SUBGRID-SCALE MODEL FOR LARGE-EDDY SIMULATION BASED ON THE PHYSICS OF INTERSCALE ENERGY TRANSFER IN TURBULENCE by Brian Wayne Anderson A Dissertation Presented to the FACULTY OF THE USC GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Ful llment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (AEROSPACE ENGINEERING) May 2012 Copyright 2012 Brian Wayne Anderson|