How do we predict Vortex Shedding?
The prediction of vortex shedding is only possible by mathematical calculations. It can be predicted by the non-dimensional Strohal Number. This number is also expressed as ‘St’, and the equation is known as vortex shedding frequency equation. The formula of finding the value of St Number is-
‘f’ is the frequency of shedding vortices,
L is the characteristic length and, and
V is the velocity of the flow.
The value of St Number provides the indication of occurrence of vortex shedding, mathematically. It must have the value in between 0.0001 and 1 for the formation of vortex shedding.
If the value of St number lies in between the given value, the shear speed of the layers of the fluid start dissipating vortex shedding. However, if the St number is too high, the effect on the viscosity of the fluid will be high; due to this, the frictional force between the layers start opposing the formation of sheds.