Large-Eddy Simulation of Bluff-Body Flame Using the Equilibrium Combustion Model

2015 ◽  
Vol 29 (1) ◽  
pp. 179-189 ◽  
Author(s):  
Shafiq R. Qureshi ◽  
Waqar A. Khan ◽  
Robert Prosser
Keyword(s):  
Large Eddy Simulation ◽  
Bluff Body ◽  
Combustion Model ◽  
Eddy Simulation ◽  
Large Eddy

scholarly journals Large Eddy Simulation of a Bluff Body Stabilized Lean Premixed Flame

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
A. Andreini ◽  
C. Bianchini ◽  
A. Innocenti
Keyword(s):  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Turbulent Combustion ◽  
Bluff Body ◽  
Sensitivity Study ◽  
Flame Stabilization ◽  
Combustion Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Lean Premixed

The present study is devoted to verify current capabilities of Large Eddy Simulation (LES) methodology in the modeling of lean premixed flames in the typical turbulent combustion regime of Dry LowNOxgas turbine combustors. A relatively simple reactive test case, presenting all main aspects of turbulent combustion interaction and flame stabilization of gas turbine lean premixed combustors, was chosen as an affordable test to evaluate the feasibility of the technique also in more complex test cases. A comparison between LES and RANS modeling approach is performed in order to discuss modeling requirements, possible gains, and computational overloads associated with the former. Such comparison comprehends a sensitivity study to mesh refinement and combustion model characteristic constants, computational costs, and robustness of the approach. In order to expand the overview on different methods simulations were performed with both commercial and open-source codes switching from quasi-2D to fully 3D computations.

Large Eddy Simulation of Bluff Body Stabilised Turbulent Premixed Flames

1993 ◽  
Author(s):  
Roland Rydén ◽  
Lars-Erik Eriksson ◽  
Stefan Olovsson
Keyword(s):  
Large Eddy Simulation ◽  
Bluff Body ◽  
Laser Doppler Anemometry ◽  
Measurement Data ◽  
Reaction Rates ◽  
Combustion Model ◽  
Reacting Flow ◽  
Flame Holder ◽  
Eddy Simulation ◽  
Large Eddy

Flow calculations for a premixed flame behind a bluff body flame holder using a conventional finite difference code with a standard k-ε turbulence model have been found to give poor predictions of the overall flow field. A major factor is believed to be the inadequately modelled large scale turbulence in the wake region. In order to improve the numerical prediction capability a large eddy simulation (LES) technique, which has recently given very good predictions for the non-reacting flow around the same flame holder, has been extended to handle reacting flow. This paper presents a combustion model which considers the influence of turbulence on the effective chemical reaction rates and which is adapted to the LES framework. The combustion model is of the “eddy dissipation type” previously developed by Magnussen. The present flow simulation code has been applied on the premixed bluff body flow case and results are compared with measurement data from gas analysis, LDA (Laser Doppler Anemometry) and CARS techniques. Significant improvements in the overall predictions are demonstrated even on a coarse mesh.

scholarly journals A Fractal Dynamic SGS Combustion Model for Large Eddy Simulation of Turbulent Premixed Flames

2016 ◽  
Vol 188 (9) ◽  
pp. 1472-1495 ◽  
Author(s):  
Katsuhiro Hiraoka ◽  
Yuki Minamoto ◽  
Masayasu Shimura ◽  
Yoshitsugu Naka ◽  
Naoya Fukushima ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Premixed Flames ◽  
Combustion Model ◽  
Turbulent Premixed Flames ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Turbulent Premixed

Large Eddy Simulation of the Flow Around a Diffuser-Equipped Bluff Body in Ground Effect

2011 ◽  
Author(s):  
Lara Schembri Puglisevich ◽  
Gary Page
Keyword(s):  
Large Eddy Simulation ◽  
Bluff Body ◽  
Vortex Formation ◽  
Ground Effect ◽  
Vortical Flow ◽  
Navier Stokes ◽  
Flow Structures ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flow Features

Unsteady Large Eddy Simulation (LES) is carried out for the flow around a bluff body equipped with an underbody rear diffuser in close proximity to the ground, representing an automotive diffuser. The goal is to demonstrate the ability of LES to model underbody vortical flow features at experimental Reynolds numbers (1.01 × 106 based on model height and incoming velocity). The scope of the time-dependent simulations is not to improve on Reynolds-Averaged Navier Stokes (RANS), but to give further insight into vortex formation and progression, allowing better understanding of the flow, hence allowing more control. Vortical flow structures in the diffuser region, along the sides and top surface of the bluff body are successfully modelled. Differences between instantaneous and time-averaged flow structures are presented and explained. Comparisons to pressure measurements from wind tunnel experiments on an identical bluff body model shows a good level of agreement.

Very Large Eddy Simulation of Passive Drag Control for a D-Shaped Cylinder

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Xingsi Han ◽  
Siniša Krajnović
Keyword(s):  
Large Eddy Simulation ◽  
Flow Control ◽  
Control Problem ◽  
Bluff Body ◽  
Numerical Study ◽  
Numerical Results ◽  
Complex Flow ◽  
Local Disturbance ◽  
Eddy Simulation ◽  
Large Eddy

The numerical study reported here deals with the passive flow control around a two-dimensional D-shaped bluff body at a Reynolds number of Re=3.6×104. A small circular control cylinder located in the near wake behind the main bluff body is employed as a local disturbance of the shear layer and the wake. 3D simulations are carried out using a newly developed very large eddy simulation (VLES) method, based on the standard k − ε turbulence model. The aim of this study is to validate the performance of this method for the complex flow control problem. Numerical results are compared with available experimental data, including global flow parameters and velocity profiles. Good agreements are observed. Numerical results suggest that the bubble recirculation length is increased by about 36% by the local disturbance of the small cylinder, which compares well to the experimental observations in which the length is increased by about 38%. A drag reduction of about 18% is observed in the VLES simulation, which is quite close to the experimental value of 17.5%. It is found that the VLES method is able to predict the flow control problem quite well.

Sign in / Sign up

Export Citation Format

Share Document