Comparison of flow characteristics around an equilateral triangular cylinder via PIV and Large Eddy Simulation methods
Küçük Resim Yok
Tarih
2017
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
ELSEVIER SCI LTD
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
The flow structures around an equilateral triangular Cylinder, which is commonly used as a vortex shedder in the vortex flowmeter, were investigated experimentally and numerically. Flow characteristics such as voracity contours, patterns of sectional streamlines, velocity vectors, velocity fields, Reynolds stress correlations, Strouhal numbers and drag coefficients were examined using the Particle Image Velocimetry (PIV) technique and the Large Eddy Simulation (LES) turbulence model. Experimental studies were performed in an open water channel for Re= 2.9 x 10(3), Re= 5.8 x 10(3) and Re = 1.16 x 10(4) based on the equilateral triangle edge. A sharp-tip corner of the cylinder with a triangle cross-section was exposed to the upstream side while the other two sharp -tip corners were placed on the downstream side. Numerical studies were also completed at Reynolds numbers in the range of 2.9 x 103 <= Re <= 1.16 x 10(5) to obtain the changes in the Strouhal numbers and drag coefficients. When the results of PIV and LES are considered in the same interval of Reynolds numbers, the maximum and minimum values of each flow pattern were nearly the same. The time -averaged patterns had considerable symmetry with respect to the axis line passing through the sharp -tip corner of the cross-section of the triangular cylinder. The Strouhal number was independent of the Reynolds number and was found to be approximately 0.22. The drag coefficient decreased with increasing Reynolds numbers while increasing the Power Spectral Density (PSD) and the vortex shedding frequency. For the same Reynolds numbers, the experimental and numerical results were in good agreement. Therefore, the LES turbulence model is recommended for applications of flow around this type of bluff body that is generally used in the design of vortex flowmeters to generate vortex shedding.
Açıklama
Anahtar Kelimeler
Equilateral triangular cylinder, Large Eddy Simulation (LES), Particle Image Velocimetry (PIV), Strouhal number, Vortex flowmeter, Vortex shedding
Kaynak
FLOW MEASUREMENT AND INSTRUMENTATION
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
55
