On the non-equilibrium models for subfilter scalar variance in large eddy simulation of turbulent mixing and combustion

2019 ◽  
Vol 31 (2) ◽  
pp. 025112 ◽  
Author(s):  
Abhishek Jain ◽  
Seung Hyun Kim
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Mixing ◽  
Equilibrium Models ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Scalar Variance ◽  
Non Equilibrium

scholarly journals Implicit large eddy simulation of shock-driven material mixing

2013 ◽  
Vol 371 (2003) ◽  
pp. 20120217 ◽  
Author(s):  
F. F. Grinstein ◽  
A. A. Gowardhan ◽  
J. R. Ristorcelli
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Mixing ◽  
Initial Conditions ◽  
Spatial Scales ◽  
Late Time ◽  
Eddy Simulation ◽  
Geometrical Complexity ◽  
Planar Shock ◽  
Large Eddy ◽  
Implicit Large Eddy Simulation

Under-resolved computer simulations are typically unavoidable in practical turbulent flow applications exhibiting extreme geometrical complexity and a broad range of length and time scales. An important unsettled issue is whether filtered-out and subgrid spatial scales can significantly alter the evolution of resolved larger scales of motion and practical flow integral measures. Predictability issues in implicit large eddy simulation of under-resolved mixing of material scalars driven by under-resolved velocity fields and initial conditions are discussed in the context of shock-driven turbulent mixing. The particular focus is on effects of resolved spectral content and interfacial morphology of initial conditions on transitional and late-time turbulent mixing in the fundamental planar shock-tube configuration.

scholarly journals Stably Stratified Flows: A Model with No Ri(cr)*

2008 ◽  
Vol 65 (7) ◽  
pp. 2437-2447 ◽  
Author(s):  
V. M. Canuto ◽  
Y. Cheng ◽  
A. M. Howard ◽  
I. N. Esau
Keyword(s):  
Numerical Simulation ◽  
Large Eddy Simulation ◽  
Direct Numerical Simulation ◽  
Turbulent Mixing ◽  
Stratified Flows ◽  
The Other ◽  
Large Set ◽  
Eddy Simulation ◽  
Stably Stratified Flows ◽  
Large Eddy

Abstract A large set of laboratory, direct numerical simulation (DNS), and large eddy simulation (LES) data indicates that in stably stratified flows turbulent mixing exists up to Ri ∼ O(100), meaning that there is practically no Ri(cr). On the other hand, traditional local second-order closure (SOC) models entail a critical Ri(cr) ∼ O(1) above which turbulence ceases to exist and are therefore unable to explain the above data. The authors suggest how to modify the recent SOC model of Cheng et al. to reproduce the above data for arbitrary Ri.

Analysis and Optimization of Turbulent Mixing With Large Eddy Simulation

2006 ◽  
Author(s):  
Ying Huai ◽  
Amsini Sadiki
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Mixing ◽  
Optimization Procedure ◽  
Impinging Jet ◽  
Computational Domain ◽  
Original Design ◽  
Mixing Processes ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Practical Engineering

In this work, Large Eddy Simulation (LES) has been carried out to analyze the turbulent mixing processes in an impinging jet configuration. To characterize and quantify turbulent mixing processes, in terms of scalar structures and degree of mixing, three parameters have been basically introduced. They are “mixedness parameter”, which represents the probability of mixed fluids in computational domain, the Spatial Mixing Deficiency (SMD) and the Temporal Mixing Deficiency (TMD) parameters for characterizing the mixing at different scalar scale degrees. With help of these parameters, a general mixing optimization procedure has then been suggested and achieved in an impinging jet configuration. An optimal jet angle was estimated and the overall mixing degree with this jet angle reached around six times more than the original design. It turns out that the proposed idea and methodology can be helpful for practical engineering design processes.

An improved dynamic non-equilibrium wall-model for large eddy simulation

2014 ◽  
Vol 26 (1) ◽  
pp. 015108 ◽  
Author(s):  
George Ilhwan Park ◽  
Parviz Moin
Keyword(s):  
Large Eddy Simulation ◽  
Wall Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Non Equilibrium
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