Large-Eddy Simulation of Complex Geometry Jets

2012 ◽  
Vol 28 (2) ◽  
pp. 235-245 ◽  
Author(s):  
Simon Eastwood ◽  
Hao Xia ◽  
Paul G. Tucker
Keyword(s):  
Large Eddy Simulation ◽  
Complex Geometry ◽  
Eddy Simulation ◽  
Large Eddy

The Characteristics Research of Tube Vortex Based on Large Eddy Simulation

2011 ◽  
Vol 121-126 ◽  
pp. 3657-3661
Author(s):  
Dun Zhang ◽  
Yuan Zheng ◽  
Ying Zhao ◽  
Jian Jun Huang
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Complex Geometry ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Computational Method ◽  
Francis Turbine ◽  
Eddy Simulation ◽  
Large Eddy

Numerical simulation of three-dimensional transient turbulent flow in the whole flow passage of a Francis turbine were based upon the large eddy simulation(LES) technique on Smargorinsky model and sliding mesh technology. The steady flow data simulated with the standard k-εmodel was used as the initial conditions for the unsteady simulation. The results show that LES can do well transient turbulent flow simulation in a Francis turbine with complex geometry. The computational method provides some reference for exploring the mechanism of eddy formation in a complex turbulent of hydraulic machinery.

scholarly journals Large-Eddy Simulation of Light-Round in an Annular Combustor With Liquid Spray Injection and Comparison With Experiments

2017 ◽  
Author(s):  
Théa Lancien ◽  
Kevin Prieur ◽  
Daniel Durox ◽  
Sébastien Candel ◽  
Ronan Vicquelin
Keyword(s):  
Large Eddy Simulation ◽  
Flame Propagation ◽  
High Speed ◽  
Complex Geometry ◽  
Numerical Study ◽  
Ignition Process ◽  
Two Phase ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Annular Combustor

A combined experimental and numerical study of light-round, defined as the flame propagation from burner to burner in an annular combustor, under perfectly premixed conditions has previously demonstrated the ability of large-eddy simulation (LES) to predict such ignition processes in a complex geometry using massively parallel computations. The present investigation aims at developing light-round simulations in a configuration closer to real applications by considering liquid n-heptane injection. The large-eddy simulation of the ignition sequence of a laboratory scale annular combustion chamber comprising sixteen swirled two-phase injectors is carried out with a mono-disperse Eulerian approach for the description of the liquid phase. The objective is to assess this modeling approach to describe the two-phase reactive flow during the ignition process. The simulation results are compared in terms of flame structure and light-round duration to the corresponding experimental images of the flame front recorded by a high-speed intensified CCD camera. The dynamics of the flow is also analyzed to identify and characterize mechanisms controlling flame propagation during the light-round process.

Large eddy simulation applications in gas turbines

2009 ◽  
Vol 367 (1899) ◽  
pp. 2827-2838 ◽  
Author(s):  
Kevin Menzies
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Complex Geometry ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Wide Range ◽  
Large Eddy ◽  
Design Cycle ◽  
Flow Phenomena

The gas turbine presents significant challenges to any computational fluid dynamics techniques. The combination of a wide range of flow phenomena with complex geometry is difficult to model in the context of Reynolds-averaged Navier–Stokes (RANS) solvers. We review the potential for large eddy simulation (LES) in modelling the flow in the different components of the gas turbine during a practical engineering design cycle. We show that while LES has demonstrated considerable promise for reliable prediction of many flows in the engine that are difficult for RANS it is not a panacea and considerable application challenges remain. However, for many flows, especially those dominated by shear layer mixing such as in combustion chambers and exhausts, LES has demonstrated a clear superiority over RANS for moderately complex geometries although at significantly higher cost which will remain an issue in making the calculations relevant within the design cycle.

scholarly journals Large eddy simulation of flows in industrial compressors: a path from 2015 to 2035

2014 ◽  
Vol 372 (2022) ◽  
pp. 20130323 ◽  
Author(s):  
N. Gourdain ◽  
F. Sicot ◽  
F. Duchaine ◽  
L. Gicquel
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flows ◽  
Complex Geometry ◽  
Current Status ◽  
Navier Stokes ◽  
Future Research ◽  
Phase Lag ◽  
Eddy Simulation ◽  
Large Eddy ◽  
High Reynolds

A better understanding of turbulent unsteady flows is a necessary step towards a breakthrough in the design of modern compressors. Owing to high Reynolds numbers and very complex geometry, the flow that develops in such industrial machines is extremely hard to predict. At this time, the most popular method to simulate these flows is still based on a Reynolds-averaged Navier–Stokes approach. However, there is some evidence that this formalism is not accurate for these components, especially when a description of time-dependent turbulent flows is desired. With the increase in computing power, large eddy simulation (LES) emerges as a promising technique to improve both knowledge of complex physics and reliability of flow solver predictions. The objective of the paper is thus to give an overview of the current status of LES for industrial compressor flows as well as to propose future research axes regarding the use of LES for compressor design. While the use of wall-resolved LES for industrial multistage compressors at realistic Reynolds number should not be ready before 2035, some possibilities exist to reduce the cost of LES, such as wall modelling and the adaptation of the phase-lag condition. This paper also points out the necessity to combine LES to techniques able to tackle complex geometries. Indeed LES alone, i.e. without prior knowledge of such flows for grid construction or the prohibitive yet ideal use of fully homogeneous meshes to predict compressor flows, is quite limited today.

Soot prediction by Large-Eddy Simulation of complex geometry combustion chambers

2013 ◽  
Vol 341 (1-2) ◽  
pp. 230-237 ◽  
Author(s):  
Guillaume Lecocq ◽  
Ignacio Hernández ◽  
Damien Poitou ◽  
Eléonore Riber ◽  
Bénédicte Cuenot
Keyword(s):  
Large Eddy Simulation ◽  
Complex Geometry ◽  
Combustion Chambers ◽  
Eddy Simulation ◽  
Large Eddy

Extending Seventh-Order Dissipative Compact Scheme Satisfying Geometric Conservation Law to Large Eddy Simulation on Curvilinear Grids

2015 ◽  
Vol 7 (4) ◽  
pp. 407-429 ◽  
Author(s):  
Yi Jiang ◽  
Meiliang Mao ◽  
Xiaogang Deng ◽  
Huayong Liu
Keyword(s):  
Large Eddy Simulation ◽  
Conservation Law ◽  
Numerical Solutions ◽  
Complex Geometry ◽  
Delta Wing ◽  
Hybrid Cell ◽  
Compact Scheme ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Seventh Order

AbstractSeventh-order hybrid cell-edge and cell-node dissipative compact scheme (HDCS-E8T7) is extended to a new implicit large eddy simulation named HILES on stretched and curvilinear meshes. Although the conception of HILES is similar to that of monotone integrated LES (MILES), i.e., truncation error of the discretization scheme itself is employed to model the effects of unresolved scales, HDCS-E8T7 is a new high-order finite difference scheme, which can eliminate the surface conservation law (SCL) errors and has inherent dissipation. The capability of HILES is tested by solving several benchmark cases. In the case of flow past a circular cylinder, the solutions of HILES fulfilling the SCL have good agreement with the corresponding experiment data, however, the flowfield is gradually contaminated when the SCL error is enlarged. With the help of fulling the SCL, ability of HILES for handling complex geometry has been enhanced. The numerical solutions of flow over delta wing demonstrate the potential of HILES in simulating turbulent flow on complex configuration.

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