scholarly journals Large eddy simulations of differential molecular diffusion in non-reacting turbulent jets of H2/CO2mixing with air

2014 ◽  
Vol 26 (2) ◽  
pp. 025102 ◽  
Author(s):  
G. Maragkos ◽  
P. Rauwoens ◽  
D. Fauconnier ◽  
B. Merci
Keyword(s):  
Molecular Diffusion ◽  
Turbulent Jets ◽  
Large Eddy Simulations ◽  
Large Eddy

Large eddy simulations of sound radiation from subsonic turbulent jets

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 1469-1477
Author(s):  
W. Zhao ◽  
S. H. Frankel ◽  
L. Mongeau
Keyword(s):  
Sound Radiation ◽  
Turbulent Jets ◽  
Large Eddy Simulations ◽  
Large Eddy

A strategy for large-scale scalar advection in large eddy simulations that use the linear eddy sub-grid mixing model

2018 ◽  
Vol 28 (10) ◽  
pp. 2463-2479 ◽  
Author(s):  
Salman Arshad ◽  
Bo Kong ◽  
Alan Kerstein ◽  
Michael Oevermann
Keyword(s):  
Turbulent Mixing ◽  
Large Scale ◽  
Molecular Diffusion ◽  
Passive Scalar ◽  
Mixing Model ◽  
Large Eddy Simulations ◽  
High Flux ◽  
Scalar Mixing ◽  
Content Type ◽  
Large Eddy

PurposeThe purpose of this numerical work is to present and test a new approach for large-scale scalar advection (splicing) in large eddy simulations (LES) that use the linear eddy sub-grid mixing model (LEM) called the LES-LEM.Design/methodology/approachThe new splicing strategy is based on an ordered flux of spliced LEM segments. The principle is that low-flux segments have less momentum than high-flux segments and, therefore, are displaced less than high-flux segments. This strategy affects the order of both inflowing and outflowing LEM segments of an LES cell. The new splicing approach is implemented in a pressure-based fluid solver and tested by simulation of passive scalar transport in a co-flowing turbulent rectangular jet, instead of combustion simulation, to perform an isolated investigation of splicing. Comparison of the new splicing with a previous splicing approach is also done.FindingsThe simulation results show that the velocity statistics and passive scalar mixing are correctly predicted using the new splicing approach for the LES-LEM. It is argued that modeling of large-scale advection in the LES-LEM via splicing is reasonable, and the new splicing approach potentially captures the physics better than the old approach. The standard LES sub-grid mixing models do not represent turbulent mixing in a proper way because they do not adequately represent molecular diffusion processes and counter gradient effects. Scalar mixing in turbulent flow consists of two different processes, i.e. turbulent mixing that increases the interface between unmixed species and molecular diffusion. It is crucial to model these two processes individually at their respective time scales. The LEM explicitly includes both of these processes and has been used successfully as a sub-grid scalar mixing model (McMurtry et al., 1992; Sone and Menon, 2003). Here, the turbulent mixing capabilities of the LES-LEM with a modified splicing treatment are examined.Originality/valueThe splicing strategy proposed for the LES-LEM is original and has not been investigated before. Also, it is the first LES-LEM implementation using unstructured grids.

A Tabulated, Flamelet Based No Model for Large Eddy Simulations of Non Premixed Turbulent Jets with Enthalpy Loss

2015 ◽  
Vol 94 (4) ◽  
pp. 691-729 ◽  
Author(s):  
Carlo Locci ◽  
Olivier Colin ◽  
Damien Poitou ◽  
Fabian Mauss
Keyword(s):  
Turbulent Jets ◽  
Large Eddy Simulations ◽  
Large Eddy

Large Eddy Simulations of Sound Radiation from Subsonic Turbulent Jets

AIAA Journal ◽  
2001 ◽  
Vol 39 (8) ◽  
pp. 1469-1477 ◽  
Author(s):  
W. Zhao ◽  
S. H. Frankel ◽  
L. Mongeau
Keyword(s):  
Sound Radiation ◽  
Turbulent Jets ◽  
Large Eddy Simulations ◽  
Large Eddy

scholarly journals Large-eddy simulations of variable-density turbulent jets

2018 ◽  
Vol 1128 ◽  
pp. 012016
Author(s):  
V Ivashchenko ◽  
V Ryzhenkov ◽  
R Mullyadzhanov
Keyword(s):  
Turbulent Jets ◽  
Variable Density ◽  
Large Eddy Simulations ◽  
Large Eddy

Full-Field Dependence on Inlet Modeling of Non-Isothermal Turbulent Jets Using Validated Large Eddy Simulations

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Sasan Salkhordeh ◽  
Mark L. Kimber
Keyword(s):  
Near Field ◽  
Turbulent Jets ◽  
Vital Role ◽  
Large Eddy Simulations ◽  
Turbulent Jet ◽  
Far Field ◽  
Current Effort ◽  
Full Field ◽  
Large Eddy ◽  
Inlet Conditions

Inlet conditions for a turbulent jet are known to affect the near field behavior but eventually lose their significance downstream. Metrics of importance are often derived from mean and fluctuating velocity components, but little has been done to explore inlet effects on transport of a scalar quantity (e.g., temperature). This paper aims to provide fundamental understanding in this regard and employs large eddy simulations (LES) of a nonisothermal round turbulent jet (Reynolds number of 16,000) with geometry and boundary conditions mimicked after a well-known experimental study. The jet inlet is first modeled with a standard Blasius profile and next by performing a simulation of the upstream flow modeled with either detached eddy simulations (DES) or LES for the second and third approaches, respectively. Only the model employing LES for both upstream nozzle and downstream jet is found to completely capture the root-mean-square (RMS) temperature behavior, namely, a distinct hump when normalized by the local mean centerline temperature at roughly five diameters downstream. Regarding the far field conditions, all three inlet conditions converge for the centerline values, but the radial distributions still portray non-negligible differences. Not surprisingly, the complete LES modeling approach agrees the best with experimental data for mean and RMS distributions, suggesting that the inlet condition plays a vital role in both the near and far field of the jet. The current effort is the very first LES study to successfully capture flow physics for a nonisothermal round turbulent jet in near and far field locations.

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