Vortex flowmeter measurement principle introduction

Vortex flowmeter measurement principle:
       When the fluid flows through a vortex generator disposed in a smooth flow at a certain flow rate, a pair of alternately arranged and arranged vortexes (vortex streets) are generated downstream of the cylinder, first on one side of the cylinder, and then on The other side of the cylinder is produced. This theory of generating vortices was first proposed by Karman, named Carmen vortex street, and gives the relationship between frequency and flow velocity, where the coefficient is named Strohal number.