Control of the flow past a sphere near a flat wall using passive jet
Küçük Resim Yok
Tarih
2019
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Pergamon-Elsevier Science Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In the present investigation, interactions between the vortices shedding from a single sphere and the boundary layer flow over a flat plate with various gap ratios have been investigated at Re = 5000 using the techniques of dye visualization and Particle Image Velocimetry. A passive jet has been created to control the flow past the sphere by a hole drilled into the sphere from the forward stagnation point to the rear of the sphere with various diameters. The results show that the complex flow downstream of the sphere, which is occurred from the combination of 'Carman vortex street and the boundary layer over the flat plate can be controlled by a passive jet. Because the jet flow interrupts periodicity of the vortices shedding from the sphere by supplying fluid flow into the wake with relatively high velocity. Presence of the hole significantly attenuates the magnitudes of the turbulence characteristics. Furthermore, the magnitudes of the turbulence characteristics decrease with increasing the hole diameter depending on the location of the sphere in the boundary layer. However, a larger hole diameter can result in higher turbulence levels in the region of the passive jet. Hence, the effectiveness of the each case (the diameter of the hole) changes with the location of the sphere over the flat plate.
Açıklama
Anahtar Kelimeler
Flow Control, Passive Jet, Ply, Sphere, Turbulence
Kaynak
Ocean Engineering
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
187
