Ph.D. Proposal

Scott Theuerkauf

(Advisor: Prof. Oefelein)

"Explicit Residual Filtering for Reacting Flows"

Friday, April 14 at

12:00 p.m.

Montgomery Knight Building 325
 

Abstract

Large Eddy Simulation (LES) is a useful tool for modeling turbulent, non-statistically stationary flow without resolving the entire range of turbulent scales. Explicitly defining the filter applied to the Navier-Stokes equations is one way to control the range of scales present in the solution. This method seeks to decouple the LES solution from the grid and numerical method in order to effectively eliminate competition between the required subfilter-scale (SFS) models and the numerical discretization errors. Several methods for Explicitly Filtered (EF) LES have been attempted in the past with this goal and others in mind. The proposed work for this dissertation seeks to apply a familiar method, grounded in novel derivation from the Navier-Stokes equations governing compressible, reacting flows. By filtering the numerical residual of each equation through a discrete, commuting filter that is sufficiently sharp and wide relative to the filtering effects of the underlying numerical scheme, the implicit filtering effects of the numerical scheme and mesh can be minimized, replacing them with those of the explicitly-defined filter. Additionally, by applying the filter once to each equation, the cost of successive filter operations is minimized, reducing the cost of EF LES compared to some prior implementations. Finally, the structure of this method allows existing Implicitly-Filtered (IF) LES numerical methods to be adapted to EF LES in a straightforward and computationally efficient manner. The proposed work seeks to validate this EF method on a Taylor-Green Vortex before further validating with a compressible, reacting turbulent mixing layer. Identifying the computational costs of this approach in context with its advantages will provide the advanced knowledge necessary to achieve grid- and scheme-independent results using LES.

Committee

• Prof. Joseph Oefelein – School of Aerospace Engineering (advisor), Georgia Institute of Technology
• Prof. Vigor Yang – School of Aerospace Engineering, Georgia Institute of Technology
• Prof. Pui Kuen Yeung – School of Aerospace Engineering, Georgia Institute of Technology
• Prof. Yingjie Liu – School of Mathematics, Georgia Institute of Technology