Quantifying Swirl Number Effects on Recirculation Zones and Vortex Dynamics in a Dual-Swirl Combustor


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Sehole H. A. H., Mehdi G., Riaz R., Ul Jabbar A., Maqsood A., De Giorgi M. G.

ENERGIES, cilt.18, sa.24, 2025 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 18 Sayı: 24
  • Basım Tarihi: 2025
  • Doi Numarası: 10.3390/en18246568
  • Dergi Adı: ENERGIES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, Directory of Open Access Journals
  • Orta Doğu Teknik Üniversitesi Kuzey Kıbrıs Kampüsü Adresli: Hayır

Özet

Swirl-stabilized combustors are central to gas turbine technology, where the swirl number critically determines flow structure and combustion stability. This work systematically investigates the isothermal flow in a dual-swirl combustor, focusing on two primary objectives: evaluating advanced turbulence models and quantifying the impact of geometric-induced swirl number variations. Large Eddy Simulation (LES), Detached Eddy Simulation (DES), Scale-Adaptive Simulation (SAS), and the k-omega SST RANS model are compared against experimental data. The results suggest that while all models capture the mean recirculation zones, the scale-resolving approaches (LES, DES, SAS) more accurately predict the unsteady dynamics, such as shear layer fluctuations and the precessing vortex core, which are challenging for the RANS model. Furthermore, a parametric study of vane angles (60 degrees to 70 degrees) reveals a non-monotonic relationship between geometry and the resulting swirl number, attributed to internal flow separation. An intermediate swirl number range (S approximate to 0.79) was found to promote stable and coherent recirculation zones, whereas higher swirl numbers led to more intermittent flow structures. These findings may provide practical guidance for selecting turbulence models and optimizing swirler geometry in the design of modern combustors.