Romit Maulik, 2017 CADRE conference poster
Graduate Student, Mechanical & Aerospace Engineering
Oklahoma State University
Poster Title: "Implicit LES Modeling of Stratified Shear Layer Turbulence"
Romit Maulik, Omer San (advisor)
Abstract: Solving two-dimensional compressible turbulence problems up to a resolution of $16384^2$, this paper investigates the characteristics of two promising computational approaches: (i) an implicit or numerical large eddy simulation (ILES) framework using upwind-based fifth-order weighted essentially non-oscillatory (WENO) reconstruction algorithms equipped with several Reimann solvers, and (ii) a central sixth-order reconstruction framework combined with various linear and nonlinear explicit low-pass spatial filtering processes. Our primary aim is to quantify the dissapative behavior, resolution characteristics, shock capturing ability and computational expenditure for each approach utilizing a systematic analysis with respect to its modeling parameters or parameterizations. The relative advantages and disadvantages of both approaches are addressed for solving a stratified Kelvin-Helmholtz instability shear layer problem as well as a canonical Riemann problem with the interaction of four shocks. The comparisons are both qualitative and quantitative, using visualizations of the spatial structure of the flow and energy spectra, respectively. We observe that the central scheme, with relaxation filtering, offers a competitive approach to ILES and is much more computationally efficient than WENO-based schemes.