Flow Separation, Strouhal Number,Vortex Shedding, wake width
Abstract
The vortex flow meter is a device that works on the principle of shedding of vortices behind a bluff body placed in the flow. In the fifteenth century the great Italian painter Leonardo Da Vinci described and drew accurately the vortices behind cylindrical body.Later in 1878 Strouhal based on his observation published a relation for the vortex shedding frequency. This relation later represented in dimensionless form as:
St= (f *d/Um)
The first theoretical investigation on this subject was reported in1911. Von Karman derived the geometrical pattern of the vortices behind a circular cylinder based on linear stability analysis. He also established a theoretical link between the vortex street structure and drag experienced by the body. In the early stage there was a lot of discrepancy in the literature related to the choice of appropriate characteristic length for defining the non-dimensional Strouhal number.
