Large-Eddy Simulation and Experimental Observation of Combustion-Induced Vortex Breakdown

2010 ◽  
Vol 182 (4-6) ◽  
pp. 505-516 ◽  
Author(s):  
E. Tangermann ◽  
M. Pfitzner ◽  
M. Konle ◽  
T. Sattelmayer
Keyword(s):  
Large Eddy Simulation ◽  
Experimental Observation ◽  
Vortex Breakdown ◽  
Eddy Simulation ◽  
Large Eddy

Large-Eddy Simulation of a Swirl-Stabilized, Lean Direct Injection Spray Combustor

2006 ◽  
Author(s):  
Mehmet Kırtas¸ ◽  
Nayan Patel ◽  
Vaidyanathan Sankaran ◽  
Suresh Menon
Keyword(s):  
Large Eddy Simulation ◽  
Vortex Breakdown ◽  
Direct Injection ◽  
Reacting Flow ◽  
Mean Velocity ◽  
Recirculation Bubble ◽  
Lean Direct Injection ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Recirculation Zones

Large-eddy simulation (LES) of a lean-direct injection (LDI) combustor is reported in this paper. The full combustor and all the six swirl vanes are resolved and both cold and reacting flow simulations are performed. Cold flow predictions with LES indicate the presence of a broad central recirculation zone due to vortex breakdown phenomenon near the dump plane and two corner recirculation zones at the top and bottom corner of the combustor. These predicted features compare well with the experimental non-reacting data. Reacting case simulated a liquid Jet-A fuel spray using a Lagrangian approach. A three-step kinetics model that included CO and NO is used for the chemistry. Comparison of mean velocity field predicted in the reacting LES with experiments shows reasonable agreement. Comparison with the non-reacting case shows that the centerline recirculation bubble is shorter but more intense in the reacting case.

Trailing Edge 3D Free Shear Layers

2000 ◽  
Author(s):  
N. Schröder ◽  
G. Hofmann ◽  
J. Hourmouziadis
Keyword(s):  
Flow Field ◽  
Large Eddy Simulation ◽  
Vortex Breakdown ◽  
Mixing Layer ◽  
Streamwise Vortex ◽  
Two Dimensional ◽  
Development Length ◽  
Trailing Edge ◽  
Eddy Simulation ◽  
Large Eddy

This paper reports on an investigation of coherent structures and the characteristic flow field of trailing edge shed vorticity, which can be found downstream of blade rows as well as behind lobed exhaust mixers. The corresponding, fundamental flow case of a free, skewed mixing layer was studied both experimentally in a low-speed test facility and numerically using Standard k,ε-Model and Large Eddy Simulation (LES). The investigation gave a new insight into the flow structure. Along the complete development length there is a coexistence of the streamwise vortices generated by cross-shear with the spanwise vorticity of Von-Karman vortex street or two-dimensional Kelvin-Helmholtz instability. This was confirmed by extensive flow-field measurements using five-hole probes and X-wire anemometry as well as by CFD. The measurement of the mixing layer spreading resulted in a growth rate of the skewed mixing layer very similar to that of the two-dimensional flow. The development of energy thickness downstream of the trailing edge, representing the mixing losses, was found to be practically independent of skewing angle. The spacing and the fluctuation of the streamwise vortex cores were not accessible to probe measurement, but were determined by visualization and large eddy simulation. The separation of vorticity-components gave stable distributions in streamwise and spanwise direction until vortex breakdown, which appears to be independent of the initial state of the boundary layer. A criterion for streamwise vortex breakdown was identified by correcting the development length with the equivalent shear layer parameter. The content of turbulent kinetic energy as a measure for turbulence production and mixing efficiency is discussed.

Large-Eddy Simulation of Swirling Turbulent Jet Flows in Absence of Vortex Breakdown

AIAA Journal ◽  
2009 ◽  
Vol 47 (12) ◽  
pp. 3011-3021 ◽  
Author(s):  
Celestin P. Zemtsop ◽  
Michael K. Stöllinger ◽  
Stefan Heinz ◽  
Dan Stanescu
Keyword(s):  
Large Eddy Simulation ◽  
Vortex Breakdown ◽  
Turbulent Jet ◽  
Jet Flows ◽  
Eddy Simulation ◽  
Large Eddy

Large eddy simulation of vortex breakdown/flame interaction

2007 ◽  
Vol 19 (7) ◽  
pp. 075103 ◽  
Author(s):  
Christophe Duwig ◽  
Laszlo Fuchs
Keyword(s):  
Large Eddy Simulation ◽  
Vortex Breakdown ◽  
Eddy Simulation ◽  
Large Eddy
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