NUMERICAL STUDY OF VORTEX FLOW METERS

This study relates to the flow meters which are widely used in industry for flow measurements. In a vortex meter occurs a phenomenon of vortex shedding which produces a periodic signal. The frequency of the latter is proportional to the volumetric flow rate. Through this numerical study we show the significant influence of the shape of the bluff body on the performances of these apparatuses. The stabilized finite element method known as GLS (Galerkin Least Squares) is used in order to simulate the flow of the fluid, assumed Newtonian and incompressible. For the modelling of turbulence we used the LES (Large Eddy Simulation) method. The undertaken comparative study, relates to the obstacles having a section which can be square, triangular or in the shape of the letter T. The performances of the meters using each type of obstacle are checked numerically for different Reynolds numbers. A detailed attention is given to the step of time used in order to avoid numerical instability and also to be able to capture the low frequency of vortex shedding. For the calculation of Strouhal number we use the FFT method (Fast Fourier Transformation).