A Numerical Study of Flow Dynamics in an Annular Combustor with Multiple Swirl Injectors

2010 ◽  
Author(s):  
Hong-Gye Sung ◽  
Jong-Chan Kim ◽  
Liwei Zhang ◽  
Vigor Yang ◽  
Kwang-Hee Yoo
Keyword(s):  
Numerical Study ◽  
Flow Dynamics ◽  
Swirl Injectors ◽  
Annular Combustor

Study of Flow and Convective Heat Transfer in a Simulated Scaled Up Low Emission Annular Combustor

2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Sunil Patil ◽  
Teddy Sedalor ◽  
Danesh Tafti ◽  
Srinath Ekkad ◽  
Yong Kim ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Convective Heat ◽  
Swirling Flow ◽  
Numerical Study ◽  
Swirl Number ◽  
Maximum Heat ◽  
Number Range ◽  
Maximum Heat Transfer ◽  
Annular Combustor

Modern dry low emissions (DLE) combustors are characterized by highly swirling and expanding flows that makes the convective heat load on the gas side difficult to predict and estimate. A coupled experimental–numerical study of swirling flow inside a DLE annular combustor model is used to determine the distribution of heat transfer on the liner walls. Three different Reynolds numbers are investigated in the range of 210,000–840,000 with a characteristic swirl number of 0.98. The maximum heat transfer coefficient enhancement ratio decreased from 6 to 3.6 as the flow Reynolds number increased from 210,000 to 840,000. This is attributed to a reduction in the normalized turbulent kinetic energy in the impinging shear layer, which is strongly dependent on the swirl number that remains constant at 0.98 for the Reynolds number range investigated. The location of peak heat transfer did not change with the increase in Reynolds number since the flow structures in the combustors did not change with Reynolds number. Results also showed that the heat transfer distributions in the annulus have slightly different characteristics for the concave and convex walls. A modified swirl number accounting for the step expansion ratio is defined to facilitate comparison between the heat transfer characteristics in the annular combustor with previous work in a can combustor. A higher modified swirl number in the annular combustor resulted in higher heat transfer augmentation and a slower decay with Reynolds number.

Flow Dynamics of Vibrated Dense Granular Materials in the Presence of Ambient Gas

Volume 2 ◽  
2004 ◽  
Author(s):  
Azita Soleymani ◽  
Piroz Zamankhan ◽  
Hassan Yousefi ◽  
William Polashenski ◽  
Vesa Tanskanen
Keyword(s):  
Granular Materials ◽  
Numerical Study ◽  
Vertical Direction ◽  
Critical Value ◽  
Flow Dynamics ◽  
Particle Phase ◽  
Narrow Gap ◽  
Sinusoidal Oscillation ◽  
Interfacial Drag ◽  
The Continuum

Results are presented from a numerical study examining the flow dynamics of condensed granular materials in the presence of an interstitial gas in a narrow gap between two concentric cylindrical buckets subjected to sinusoidal oscillation in the vertical direction of the form z = Asin(ωt), where the parameter Γ = Aω2/g exceeds a critical value, Γc, above which the system becomes fluidized. Using a recently developed expression for the stress tensor of particle phase, a set of conservation equations were derived for the particle and fluid phases interacting via an interfacial drag force. Numerical integration of the continuum equations for the granular material in buckets revealed that above Γc, granular materials may exhibit liquid-like behavior and convection can occur creating a heap similar to that previously observed experimentally.

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.

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