Effect of swirl on combustion dynamics in a lean-premixed swirl-stabilized combustor

Abstract The effect of inlet swirl on the flow development and combustion dynamics in a lean-premixed swirl-stabilized combustor has been numerically investigated using a large-eddy-simulation (LES) technique along with a level-set flamelet library approach. Results indicate that when the inlet swirl number exceeds a critical value, a vortex-breakdown-induced central toroidal recirculation zone is established in the downstream region. As the swirl number increases further, the recirculation zone moves upstream and merges with the wake recirculation zone behind the centerbody. Excessive swirl may cause the central recirculating flow to penetrate into the inlet annulus and lead to the occurrence of flame flashback. A higher swirl number tends to increase the turbulence intensity, and consequently the flame speed. As a result, the flame surface area is reduced. The net heat release, however, remains almost unchanged because of the enhanced flame speed. Transverse acoustic oscillations often prevail under the effects of strong swirling flows, whereas longitudinal modes dominate the wave motions in cases with weak swirl. The ensuing effect on the flow/flame interactions in the chamber is substantial.

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

[2]  Joseph C. Oefelein,et al.  Modeling High-Pressure Mixing and Combustion Processes in Liquid Rocket Engines , 1998 .

[3]  Christian Oliver Paschereit,et al.  Excitation of Thermoacoustic Instabilities by Interaction of Acoustics and Unstable Swirling Flow , 2000 .

[4]  Hukam Chand Mongia,et al.  Challenges and Progress in Controlling Dynamics in Gas Turbine Combustors , 2003 .

[5]  T. Lieuwen,et al.  Introduction: Combustion Dynamics in Lean-Premixed Prevaporized (LPP) Gas Turbines , 2003 .

[6]  Y. Chao.  Recirculation structure of the coannular swirling jets in a combustor , 1988 .

[7]  Eli Turkel,et al.  On Central-Difference and Upwind Schemes , 1992 .

[8]  S. Osher,et al.  Regular Article: A PDE-Based Fast Local Level Set Method , 1999 .

[9]  Chi-Wang Shu,et al.  Shock Capturing, Level Sets and PDE Based Methods in Computer Vision and Image Processing: A Review , 2003 .

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

[11]  Suresh Menon,et al.  Swirl control of combustion instabilities in a gas turbine combustor , 2002 .

[12]  S. Menon,et al.  Open-loop control of combustion instabilities in a model gas turbine combustor , 2003 .

[13]  James F. Driscoll,et al.  Effect of Heat Release and Swirl on the Recirculation within Swirl-Stabilized Flames , 1985 .

[14]  V. Yang,et al.  Bifurcation of flame structure in a lean-premixed swirl-stabilized combustor: transition from stable to unstable flame , 2004 .

[15]  Vigor Yang,et al.  An experimental study of combustion dynamics of a premixed swirl injector , 1998 .

[16]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[17]  T. Poinsot.  Boundary conditions for direct simulations of compressible viscous flows , 1992 .

[18]  Fazle Hussain,et al.  COLLAPSE, SYMMETRY BREAKING, AND HYSTERESIS IN SWIRLING FLOWS , 1999 .

[19]  V. Yang,et al.  Unsteady Flow Evolution and Combustion Dynamics of Homogeneous Solid Propellant in a Rocket Motor , 2002 .

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