Investigation of flow structure around a horizontal cylinder at different elevations in shallow water
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Tarih
2015
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Pergamon-Elsevier Science Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Flow characteristics around a horizontal circular cylinder were investigated in shallow water. The diameter of circular cylinder, the height of shallow water and free stream velocity were kept constant during the experiments as D=30 mm, h(w)=60 mm and U=167 mm/s, respectively. Particle Image Velocimetry (PIV) was used to measure instantaneous and time-averaged velocity vector fields in the near wake region. In order to investigate the effect of immersion, the cylinder was placed at eight different elevations (h(p)) between bottom and free surface (from 7.5 to 60 mm with 7.5 mm increments). Instantaneous and time-averaged velocity vector field, corresponding streamline patterns and Reynolds stress correlation were used to analyze the behavior of the flow downstream of horizontal cylinder. The mean velocity vector field, corresponding streamline topology and Reynolds stress correlation were obtained using 500 instantaneous images. As the immersion level ratio (h(D)/D) increases, the magnitude of jet-like flow velocity goes up ranged from h(D)/D=0.25-1. Time averaged flow characteristics show that there is a difference between primary and developing circulation bubble depending on direction of rotation. This occurrence causes the entrainment and this stimulates the momentum transfer between the core and wake flow region for h(D)/D=1 and 2 cases. (C) 2014 Elsevier Ltd. All rights reserved.
Açıklama
Anahtar Kelimeler
Horizontal cylinder, Flow around the pipeline, Particle image velocimetry, Separation
Kaynak
Ocean Engineering
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
96
