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.

Comparison of Partially Averaged Navier–Stokes and Large-Eddy Simulations of the Flow Around a Cuboid Influenced by Crosswind

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Siniša Krajnović ◽  
Per Ringqvist ◽  
Branislav Basara
Keyword(s):  
Experimental Data ◽  
Large Eddy Simulation ◽  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Better Than ◽  
Good Agreement ◽  
Near Wall

The paper presents a partially averaged Navier–Stokes (PANS) simulation of the flow around a cuboid influenced by crosswind. The results of the PANS prediction are validated against experimental data and results of a large-eddy simulation (LES) made using the same numerical conditions as PANS. The PANS shows good agreement with the experimental data. The prediction of PANS was found to be better than that of the LES in flow regions where simulations suffered from poor near-wall resolution.

scholarly journals Large-eddy simulation of twin impinging jets in cross-flow

2007 ◽  
Vol 111 (1117) ◽  
pp. 195-206 ◽  
Author(s):  
Q. Li ◽  
G. J. Page ◽  
J. J. McGuirk
Keyword(s):  
Large Eddy Simulation ◽  
Cross Flow ◽  
Jet Impingement ◽  
Impinging Jets ◽  
Scale Model ◽  
Mean Flow ◽  
Eddy Simulation ◽  
Suitable Tool ◽  
Large Eddy ◽  
Good Agreement

The flow-field beneath a jet-borne vertical landing aircraft is highly complex and unsteady. large-eddy simulation is a suitable tool to predict both the mean flow and unsteady fluctuations. This work aims to evaluate the suitability of LES by applying it to two multiple jet impingement problems: the first is a simple twin impinging jet in cross-flow, while the second includes a circular intake. The numerical method uses a compressible solver on a mixed element unstructured mesh. The smoothing terms in the spatial flux are kept small by the use of a monitor function sensitive to vorticity and divergence. The WALE subgrid scale model is utilised. The simpler jet impingement case shows good agreement with experiment for mean velocity and normal stresses. Analysis of time histories in the jet shear layer and near impingement gives a dominant frequency at a Strouhal number of 0·1, somewhat lower than normally observed in free jets. The jet impingement case with an intake also gives good agreement with experimental velocity measurements, although the expansion of the grid ahead of the jets does reduce the accuracy in this region. Turbulent eddies are observed entering the intake with significant swirl. This is in qualitative agreement with experimental visualisation. The results show that LES could be a suitable tool when applied to multiple jet impingement with realistic aircraft geometry.

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

Assessment of the capabilities of FireFOAM to model large-scale fires in a well-confined and mechanically ventilated multi-compartment structure

2017 ◽  
Vol 36 (1) ◽  
pp. 3-29 ◽  
Author(s):  
Duy Le ◽  
Jeffrey Labahn ◽  
Tarek Beji ◽  
Cecile B Devaud ◽  
Elizabeth J Weckman ◽  
...  
Keyword(s):  
Experimental Data ◽  
Large Eddy Simulation ◽  
Large Scale ◽  
Detailed Comparison ◽  
Equation Model ◽  
Mechanically Ventilated ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Experimental Values ◽  
Good Agreement

This article presents a large eddy simulation study of a pool fire in a well-confined and mechanically ventilated multi-room configuration. The capabilities of FireFOAM are assessed by comparing the numerical results to a well-documented set of experimental data available from Propagation d’un Incendie pour des Scénarios Multi-locaux Elémentaires. The eddy dissipation concept, finite volume discrete ordinate method, and one k-equation model are used for combustion, thermal radiation, and sub-grid scale closure, respectively. The main boundary conditions are imposed based on the experimental profiles. A detailed comparison is made with available experimental data. Good agreement between the large eddy simulation results and experimental values is achieved for temperatures, velocity, CO2 volume concentrations, and pressures for most compartments. There are some noticeable underpredictions of temperature in the outlet room. Overall, FireFOAM is shown to have good predictive capabilities for the present confined large-scale fire scenario.

LES and PANS of Turbulent Flow Through a Staggered Tube Bundle

2017 ◽  
Author(s):  
G. Minelli ◽  
S. Krajnović ◽  
B. Basara
Keyword(s):  
Experimental Data ◽  
Large Eddy Simulation ◽  
Tube Bundle ◽  
Dominant Frequency ◽  
Navier Stokes ◽  
Numerical Techniques ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flow Through ◽  
Good Agreement

Two unsteady numerical techniques, Partially-Averaged Navier Stokes (PANS) and Large Eddy Simulation (LES), are used to predict the flow in a tube bundle. The results were compared with the existing experimental data. Both methods predicted the flow in a relatively good agreement with the experimental data although the PANS simulation used only fifty percent of the computational nodes compared to the LES. The results of the simulations are used to study the unsteadiness in the flow and identify a dominant frequency of the flow.

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

Large Eddy Simulation of a Supercritical Fuel Jet in Cross Flow using GPU-Acceleration

2016 ◽  
Author(s):  
Kalyana C. Gottiparthi ◽  
Ramanan Sankaran ◽  
Anthony M. Ruiz ◽  
Guilhem Lacaze ◽  
Joseph C. Oefelein
Keyword(s):  
Large Eddy Simulation ◽  
Cross Flow ◽  
Gpu Acceleration ◽  
Eddy Simulation ◽  
Jet In Cross Flow ◽  
Fuel Jet ◽  
Large Eddy
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