An experimental investigation of the flow control of a circular cylinder in near wake with parallel plates at Re = 7500

Durhasan T., Ekinci F., Firat E., AKILLI H.

International Journal of Heat and Fluid Flow, cilt.106, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 106
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.ijheatfluidflow.2024.109276
  • Dergi Adı: International Journal of Heat and Fluid Flow
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Applied Science & Technology Source, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: Circular cylinder, Flow control, Parallel plates, POD, Vortex shedding instabilities
  • Çukurova Üniversitesi Adresli: Evet

Özet

The vortex street suppression in the near wake region of the cylinder with parallel plates was investigated using particle image velocimetry (PIV) at Reynolds number of Re = 7500. The rigid plates are designed as flat, parallel with the free-stream direction, and located on both sides of the cylinder. Two different plate lengths (0.5D and 1D based on the cylinder diameter, D) were examined at gap ratios of g/D = 0.1, 0.3, 0.5, 0.7, and 0.9, respectively. Proper Orthogonal Decomposition (POD) analyses were also employed to reveal vortex mechanism in the near wake region. The gap ratio significantly influences the interaction of the vortices. At low gap ratios, the plates directly affect the development of shear layers on both side of the cylinder. The shear layers elongate downstream with a reduction of the vortex shedding frequency. Moreover, Reynolds shear stress, vortex shedding instabilities and vortex street are suppressed in the near wake region with the help of using parallel plates. On the other hand, vortex shedding reinforces instabilities at higher gap ratios. Besides, the most effective gap ratio is different for each the plate lengths to suppress instabilities.