LES of temporally evolving mixing layers by an eighth‐order filter scheme

Sjögreen

Hadjadj

2012

Commun. comput. phys.

Self Cite

Three high order shock-capturing schemes are compared for large eddy simulations (LES) of temporally evolving mixing layers for different convective Mach numbers ranging from the quasi-incompressible regime to highly compressible supersonic regime. The considered high order schemes are fifth-order WENO (WENO5), seventh-order WENO (WENO7) and the associated eighth-order central spatial base scheme with the dissipative portion of WENO7 as a nonlinear post-processing filter step (WENO7fi). This high order nonlinear filter method of Yee & Sjögreen is designed for accurate and efficient simulations of shock-free compressible turbulence, turbulence with shocklets and turbulence with strong shocks with minimum tuning of scheme parameters. The LES results by WENO7fi using the same scheme parameter agree well with experimental results compiled by Barone et al., and published direct numerical simulations (DNS) work of Rogers & Moser and Pantano & Sarkar, whereas results by WENO5 and WENO7 compare poorly with experimental data and DNS computations.

Section: Objective and Outlinementioning

confidence: 99%

Comparative Study of Three High Order Schemes for LES of Temporally Evolving Mixing Layers

Sjögreen

Hadjadj

2012

Commun. comput. phys.

Self Cite

“…The main difference when using the constant κ parameter is that one has to know the flow structure of the entire evolution a priori in order to select the proper constant κ parameter. Contrary to the considered low speed flow test cases, our previous investigations [4,30,3,31,5,32,1,6] for various complex high speed shock-turbulence interaction flows, employing the local κ l j+1/2 would provide an automatic selection of the amount of numerical dissipation needed at each flow location, thus, leading to a more accurate DNS and LES simulation with less tuning of parameters. The local flow sensors for high order nonlinear filter schemes are particularly important for flows with a time varying random forcing and a wide range of flow speed regimes during time-accurate evolution.…”

Section: Discussionmentioning

confidence: 91%

“…It is noted that the nonlinear filter step described above should not be confused with the LES filtering operation. For previous studies on the performance of this filter scheme in DNS and LES simulations, see [4,30,3,31,5,32,1,6]. This scheme has been validated for DNS of a 3D channel flow, 2D temporal and spatial evolving mixing layers, Richtmyer-Meshkov instability, 3D Taylor-Green vortex, 3D isotropic turbulence with shocklets, extreme condition flows, and a 3D supersonic LES of temporal evolving mixing layers comparing with experimental data.…”

Section: Local Flow Sensor For a Wide Spectrum Of Flow Speed And Shocmentioning

confidence: 91%

Numerical dissipation control in high order shock-capturing schemes for LES of low speed flows

Kotov

Journal of Computational Physics

Wray

et al. 2016

The Yee & Sjögreen adaptive numerical dissipation control in high order scheme (High Order Filter Methods for Wide Range of Compressible Flow Speeds, ICOSAHOM 09, 2009) is further improved for DNS and LES of shock-free turbulence and low speed turbulence with shocklets. There are vastly different requirements in the minimization of numerical dissipation for accurate turbulence simulations of different compressible flow types and flow speeds. Traditionally, the method of choice for shock-free turbulence and low speed turbulence are by spectral, high order central or high order compact schemes with high order linear filters. With a proper control of a local flow sensor, appropriate amount of numerical dissipation in high order shock-capturing schemes can have spectral-like accuracy for compressible low speed turbulent flows. The development of the method includes an adaptive flow sensor with automatic selection on the amount of numerical dissipation needed at each flow location for more accurate DNS and LES simulations with less tuning of parameters for flows with a wide range of flow speed regime during the time-accurate evolution, e.g., time varying random forcing. An automatic selection of the different flow sensors catered to the different flow types is constructed. A Mach curve and high-frequency oscillation indicators are used to reduce the tuning of parameters in controlling the amount of shock-capturing numerical dissipation to be employed for shockfree turbulence, low speed turbulence and turbulence with strong shocks. In Kotov et al. (High Order Numerical Methods for LES of Turbulent Flows with Shocks, ICCFD8, Chengdu, Sichuan, China, July 14-18, 2014) the LES of a turbulent flow with a strong shock by the Yee & Sjögreen scheme indicated a good agreement with the filtered DNS data. A work in progress for the application of the adaptive flow sensor for compressible turbulence with time-varying random forcing is forthcoming. The present study examines the versatility of the Yee & Sjögreen scheme for DNS and LES of traditional low speed flows without forcing. Special attention is focused on the accuracy performance of this scheme using the Smagorinsky and the Germano-Lilly SGS models.Published by Elsevier Inc.

“…For a description of the algorithms and their performance, including results of a detailed LES computation of temporal-evolving mixing layers, see e.g. [1][2][3][4][5][6]8 Furthermore, AD-PDIS3D contains three choices of solvers: standard compressible flow, compressible non-ideal MHD, 2 and chemical nonequilibrium hypersonic flows. 6 For a more detailed description see.…”

Section: Motivation Objectives and Validation Processmentioning

confidence: 99%

Variable High-Order Multiblock Overlapping Grid Methods for Mixed Steady and Unsteady Multiscale Viscous Flows, Part II: Hypersonic Nonequilibrium Flows

Lani

Sjögreen

et al. 2013

Commun. comput. phys.

The variable high-order multiblock overlapping (overset) grids method of Sjögreen & Yee [CiCP, Vol. 5, 2009] for a perfect gas has been extended to nonequilibrium flows. This work makes use of the recently developed high-order well-balanced shock-capturing schemes and their filter counterparts [Wang et al., J. Comput. Phys., 2009, 2010] that exactly preserve certain non-trivial steady state solutions of the chemical nonequilibrium governing equations. Multiscale turbulence with strong shocks and flows containing both steady and unsteady components is best treated by mixing of numerical methods and switching on the appropriate scheme in the appropriate subdomains of the flow fields, even under the multiblock grid or adaptive grid refinement framework. While low dissipative sixth- or higher-order shock-capturing filter methods are appropriate for unsteady turbulence with shocklets, second- and third- order shock-capturing methods are more effective for strong steady or nearly steady shocks in terms of convergence. It is anticipated that our variable high-order overset grid framework capability with its highly modular design will allow for an optimum synthesis of these new algorithms in such a way that the most appropriate spatial discretizations can be tailored for each particular region of the flow. In this paper some of the latest developments in single block high-order filter schemes for chemical nonequilibrium flows are applied to overset grid geometries. The numerical approach is validated on a number of test cases characterized by hypersonic conditions with strong shocks, including the reentry flow surrounding a 3D Apollo-like NASA Crew Exploration Vehicle that might contain mixed steady and unsteady components, depending on the flow conditions.