Large-eddy simulation and acoustic analysis of a turbulent flow field in a swirl-stabilized combustor

To conduct a comprehensive study on the flow characteristics and acoustic oscillation in a gas turbine combustor, a 3D large-eddy simulation (LES) was implemented. The formulation consists of the Favre-filtered conservation equations of mass, momentum, and energy. The subgrid-scale dynamics are modeled using a compressible flow version of the Smagorinsky model. To investigate the dominant coherent structure, the proper orthogonal decomposition (POD) method was used for post-processing. The combustor of concern is the LM6000, lean-premixed dry low-NOx annular combustor, developed by General Electric Aircraft Engines (GEAE). Four important characteristics of swirl flow are visualized: vortex breakdown, procession and dissipation of vortical structures, recirculation zones, and helical waves immediately downstream of the swirl injector. It is shown that the turbulent motion of swirl flow directly affects acoustic oscillation through the cycle and spectral analysis. The four most dominant acoustic modes are extracted from the flow field by the POD analysis. The transverse modes in the y and z directions are dominant in all four modes, since the pressure fields are significantly affected by swirl flow.

[1]  T. Poinsot,et al.  Studies of mean and unsteady flow in a swirled combustor using experiments, acoustic analysis, and large eddy simulations , 2005 .

[2]  R. Koch,et al.  Compressible large eddy simulation of turbulent combustion in complex geometry on unstructured meshes , 2004 .

[3]  G.,et al.  TOWARD THE LARGE-EDDY SIMULATION OF COMPRESSIBLE TURBULENT FLOWS , 2022 .

[4]  N. A. Chigier,et al.  Vortex mixing for supersonic combustion , 1969 .

[5]  Christer Fureby,et al.  LES studies of the flow in a swirl gas combustor , 2005 .

[6]  T. Colonius,et al.  Turbulence and Sound-Field POD Analysis of a Turbulent Jet , 2009 .

[7]  Hong-Gye Sung.  Unsteady flowfield in an integrated rocket ramjet engine and combustion dynamics of a gas turbine swirl-stabilized injector , 1999 .

[8]  L. Rossi,et al.  Investigation of wall normal electromagnetic actuator for seawater flow control , 2002 .

[9]  Vigor Yang,et al.  Large-Eddy Simulation of Combustion Dynamics of Lean-Premixed Swirl-Stabilized Combustor , 2003 .

[10]  Christer Fureby,et al.  LES of a Multi-burner Annular Gas Turbine Combustor , 2010 .

[11]  H. Mongia,et al.  Large-Eddy Simulation of a Gas Turbine Combustor Flow , 1999 .

[12]  Thierry Poinsot,et al.  Large Eddy Simulation of self excited azimuthal modes in annular combustors , 2009 .

[13]  Vigor Yang,et al.  Large Eddy Simulation of the Turbulent Flowfield in a Swirl Stabilized Annular Combustor , 2009 .

[14]  Vigor Yang,et al.  Systematic analysis of lean-premixed swirl-stabilized combustion , 2006 .

[15]  Hong-Gye Sung.  Combustion dynamics in a model lean-premixed gas turbine with a swirl stabilized injector , 2007 .

[16]  Ephraim Gutmark,et al.  Flow dynamics in a swirl combustor , 2002 .

[17]  Hanzhuang Liang,et al.  An experimental investigation of swirling jets , 2005, Journal of Fluid Mechanics.

[18]  Tim Lieuwen,et al.  Combustion Instabilities In Gas Turbine Engines: Operational Experience, Fundamental Mechanisms, and Modeling , 2006 .

[19]  T. Poinsot,et al.  Theoretical and numerical combustion , 2001 .