Implicit large-eddy simulation of passive scalar mixing in statistically stationary isotropic turbulence

2013 ◽  
Vol 25 (2) ◽  
pp. 025101 ◽  
Author(s):  
A. J. Wachtor ◽  
F. F. Grinstein ◽  
C. R. DeVore ◽  
J. R. Ristorcelli ◽  
L. G. Margolin
Keyword(s):  
Large Eddy Simulation ◽  
Isotropic Turbulence ◽  
Passive Scalar ◽  
Scalar Mixing ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Implicit Large Eddy Simulation

Implicit Large-Eddy Simulation of Transition and Turbulence Decay

2019 ◽  
Author(s):  
Fernando F. Grinstein
Keyword(s):  
Large Eddy Simulation ◽  
Isotropic Turbulence ◽  
Navier Stokes ◽  
Homogeneous Isotropic Turbulence ◽  
Eddy Simulation ◽  
Numerical Hydrodynamics ◽  
Geometrical Complexity ◽  
Turbulence Decay ◽  
Large Eddy ◽  
Implicit Large Eddy Simulation

Abstract Accurate predictions with quantifiable uncertainties are essential to many practical turbulent flow applications exhibiting extreme geometrical complexity and broad ranges of length and time scales. Under-resolved computer simulations are typically unavoidable in such applications, and implicit large-eddy simulation (ILES) often becomes the effective strategy. We focus on ILES initialized with well-characterized 2563 homogeneous isotropic turbulence datasets generated with direct numerical simulation (DNS). ILES is based on the LANL xRAGE code, and solutions are examined as function of resolution for 643, 1283, 2563, and 5123 grids. The ILES performance of new directionally-unsplit high-order numerical hydrodynamics algorithms in xRAGE is examined. Compared to the initial 2563 DNS, we find longer inertial subranges and higher turbulence Re for directional-split 2563 & 5123 xRAGE — attributed to having linked DNS (Navier-Stokes based) solutions to nominally inviscid (higher Re) Euler based ILES solutions. Alternatively — for fixed resolution, we find that significantly higher simulated turbulence Re can be achieved with unsplit (vs. split) discretizations.

Large-eddy simulation of a passive scalar in isotropic turbulence

1981 ◽  
Vol 104 ◽  
pp. 55-79 ◽  
Author(s):  
M. Antonopoulos-Domis
Keyword(s):  
Large Eddy Simulation ◽  
Isotropic Turbulence ◽  
Passive Scalar ◽  
Scalar Equation ◽  
Eddy Simulation ◽  
Large Eddy

TEMTY, a code for large-eddy simulation of a passive scalar in isotropic turbulence, is developed and proved by successful simulation of experiment. The role of each term in the scalar equation and the concept of prefiltering the scalar equation is examined. The ratio of the exponents in the decay of velocity and temperature intensities is found to parametrize with the ratio Λu/Λ0, where Λu, Λ0, are the velocity and temperature Taylor microscales respectively.

scholarly journals Large Eddy Simulation of Scalar Mixing in Jet in a Cross-Flow

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Asela Uyanwaththa ◽  
Weeratunge. Malalasekera ◽  
Graham Hargrave ◽  
Mark Dubal
Keyword(s):  
Experimental Data ◽  
Velocity Field ◽  
Large Eddy Simulation ◽  
Cross Flow ◽  
Passive Scalar ◽  
Scalar Mixing ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Fuel Mixing ◽  
Good Agreement

Jet in a cross-flow (JICF) is a flow arrangement found in many engineering applications, especially in gas turbine air–fuel mixing. Understanding of scalar mixing in JICF is important for low NOx burner design and operation, and numerical simulation techniques can be used to understand both spatial and temporal variation of air–fuel mixing quality in such applications. In this paper, mixing of the jet stream with the cross-flow is simulated by approximating the jet flow as a passive scalar and using the large eddy simulation (LES) technique to simulate the turbulent velocity field. A posteriori test is conducted to assess three dynamic subgrid scale models in modeling jet and cross-flow interaction with the boundary layer flow field. Simulated mean and Reynolds stress component values for velocity field and concentration fields are compared against experimental data to assess the capability of the LES technique, which showed good agreement between numerical and experimental results. Similarly, time mean and standard deviation values of passive scalar concentration also showed good agreement with experimental data. In addition, LES results are further used to discuss the scalar mixing field in the downstream mixing region.

Implicit large eddy simulation of a scalar mixing layer in fractal grid turbulence

2016 ◽  
Vol 91 (7) ◽  
pp. 074007 ◽  
Author(s):  
Tomoaki Watanabe ◽  
Yasuhiko Sakai ◽  
Kouji Nagata ◽  
Yasumasa Ito ◽  
Toshiyuki Hayase
Keyword(s):  
Large Eddy Simulation ◽  
Mixing Layer ◽  
Grid Turbulence ◽  
Scalar Mixing ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Implicit Large Eddy Simulation

Large eddy simulation of evolution of a passive scalar in plane jet

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 1509-1516 ◽  
Author(s):  
C. Le Ribault ◽  
S. Sarkar ◽  
S. A. Stanley
Keyword(s):  
Large Eddy Simulation ◽  
Passive Scalar ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Plane Jet
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