Computational and experimental investigations of the vortical flow structures in the near wake region downstream of the Ahmed vehicle model

Tunay T., Yaniktepe B., ŞAHİN B.

JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS, cilt.159, ss.48-64, 2016 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 159
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1016/j.jweia.2016.10.006
  • Dergi Adı: JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.48-64
  • Anahtar Kelimeler: Ahmed vehicle model, LES, PIV, Spectral analysis, Wake flow, NUMERICAL-SIMULATION, SIMPLIFIED CAR, BLUFF-BODY, REAR SLANT, NEAR-WAKE, AERODYNAMICS, TURBULENT, DRAG, BODIES
  • Çukurova Üniversitesi Adresli: Evet

Özet

The present study aims to investigate flow characteristics downstream of the Ahmed vehicle model using both experimental and computational methods. Ahmed vehicle model having 1/4 scale and 25 slant angle is employed at Reynolds number of Re-H=1.48x10(4). Investigations are conducted in two parts. In the first part, Large Eddy Simulation (LES) method is used to resolve the flow structures downstream of the Ahmed model, computationally. In the second part, the technique of the particle image velocimetry (PIV) is employed to obtain the flow fields downstream of the Ahmed model. The PIV and LES investigations provides time-averaged and instantaneous velocity field results, such as vorticity contours, streamline topology, velocity profiles and spectral analysis of the flow velocity. Flow features that have been predicted by computational study are in a good harmony with the results predicted by experimental studies both on the slanted surface and in the near wake region downstream of the Ahmed model. Results present that characteristics of flow features that exist on the rear slanted surface and in the near wake region of the Ahmed model exhibit great variations in a very short distance in both stream-wise and vertical direction of the flow.