Large Eddy Simulation Study of Flow Dynamics in a Multiswirler Model Combustor at Elevated Pressure and High Temperature

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Weijie Liu ◽  
Qian Yang ◽  
Ranran Xue ◽  
Huiru Wang
Keyword(s):  
High Temperature ◽  
Large Eddy Simulation ◽  
Elevated Pressure ◽  
Dominant Frequency ◽  
Flow Dynamics ◽  
Main Stage ◽  
Eddy Simulation ◽  
Precessing Vortex Core ◽  
Flow Interaction ◽  
Large Eddy

Large eddy simulation (LES) of nonreacting turbulent flow in a multiswirler model combustor is carried out at elevated pressure and high temperature. Flow interaction between the main stage and the pilot stage is discussed based on the time-averaged and instantaneous flowfield. Flow dynamics in the multiswirling flow are analyzed using a phase-averaged method. Proper orthogonal decomposition (POD) is used to extract dominant flow features in the multiswirling flow. Numerical results show that the main stage and the pilot stage flows interact with each other generating a complex flowfield. Flow interaction can be divided into three regions: converging region, merging region, and combined region. A precessing vortex core (PVC) is successfully captured in the pilot stage. PVC rotates with a first dominant frequency of 2756 Hz inducing asymmetric azimuthal flow instabilities in the pilot stage. POD analyses for the velocity fields also show dominant high-frequency modes (mode 1 and mode 2) in the pilot stage. However, the dominant energetic flow is damped rapidly downstream of the pilot stage such that it has a little effect on the main stage flow.

Flow Dynamics in a Multi-Swirler Model Combustor Based on LES and POD Analysis

2019 ◽  
Author(s):  
Weijie Liu ◽  
Huiru Wang ◽  
Qian Yang ◽  
Ranran Xue ◽  
Bing Ge ◽  
...  
Keyword(s):  
Coherent Structures ◽  
Swirling Flow ◽  
Flow Instability ◽  
Dominant Frequency ◽  
Flow Dynamics ◽  
Main Stage ◽  
Eddy Simulation ◽  
Precessing Vortex Core ◽  
Close Relationship ◽  
Pod Analysis

Abstract Swirling flow is often employed in gas turbine combustion chambers for the sake of improving flame stability. Swirling flow induces not only recirculation zones but also large coherent structures which show close relationship with flow dynamics and combustion instability. The flow dynamics including Precessing Vortex Core (PVC) in simple swirlers are extensively studied, while the flow instability characteristics in a multi-swirler combustor are not fully reported. In the present paper, Large Eddy Simulation (LES) of non-reacting turbulent swirling flow is conducted in a multi-swirler burner which comprises a pilot stage and a main stage. Flow dynamics in the multi-swirler combustor are analyzed based on phase-averaged evolution of instantaneous flowfield. Proper Orthogonal Decomposition (POD) is employed to identify the coherent structures in the multi-swirling flow. Results show that the main stage and pilot stage flow interact with each other generating highly turbulent swirling flow. PVC is successfully captured at the boundary of Main recirculation zone (MRZ) in the pilot stage with a dominant frequency of 1915 Hz. The PVC leads to periodic azimuthal flow instability. POD analyses for the velocity fields show dominant high-frequency modes (mode 1 and mode 2) in the pilot stage. However, the dominant energetic flow is damped rapidly downstream of the pilot stage that it has little effect on the main stage flow.

Large-Eddy Simulation of Single-Phase Flow Dynamics and Mixing in an Industrial Crystallizer

2007 ◽  
Vol 85 (2) ◽  
pp. 169-179 ◽  
Author(s):  
J.J. Derksen ◽  
K. Kontomaris ◽  
J.B. McLaughlin ◽  
H.E.A. Van den Akker
Keyword(s):  
Large Eddy Simulation ◽  
Single Phase ◽  
Flow Dynamics ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Eddy Simulation ◽  
Large Eddy

Large Eddy Simulation of Turbulent Axial Flow Along an Array of Rods

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
F. Abbasian ◽  
S. D. Yu ◽  
J. Cao
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flows ◽  
Large Scale ◽  
Axial Flow ◽  
Dominant Frequency ◽  
Turbulence Structure ◽  
Circular Array ◽  
Central Difference ◽  
Eddy Simulation ◽  
Large Eddy

Large eddy simulation (LES) is employed in this paper to model the axial flow along a circular array of rods with a focus on anisotropic large-scale turbulence. The circular array consists of four whole rods and eight half rods, with a pitch-to-diameter ratio of 1.08. A dynamic Smagorinsky model with SIMPLE coupling method and a bounded central difference scheme are used to reduce numerical errors. The high demands for computations of the three-dimensional turbulent flows are afforded through parallel processing and utilization of 20 processors. The numerical results obtained using LES are compared with independent experimental data available in the literature; good agreement is achieved. The LES model was developed to accurately predict (i) the dependence of turbulence intensity and dominant frequency on the gap size and (ii) the turbulence structure in different directions.

Evaluation of large Eddy simulation and Euler-Euler CFD models for solids flow dynamics in a stirred tank reactor

AIChE Journal ◽  
2008 ◽  
Vol 54 (3) ◽  
pp. 766-778 ◽  
Author(s):  
Debangshu Guha ◽  
P. A. Ramachandran ◽  
M. P. Dudukovic ◽  
J. J. Derksen
Keyword(s):  
Large Eddy Simulation ◽  
Flow Dynamics ◽  
Stirred Tank ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Eddy Simulation ◽  
Cfd Models ◽  
Large Eddy
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