Study of stability shedding frequency in vortex sonic flowmeters

The typical block diagram with detailed description signals at the input and output of major functional components is discussed.Plan of experiment for research of stability of vortex shedding frequency beyond bluff body are showed. Results of flow stability research in test lab are given. It is shown, that the variation coefficient of the instantaneous values of the reference flow rate varies from 0.13 % to 0.3 % during the vortex sonic flowmeters test depending on the flow regimes. The vortex frequency variation coefficient is 3 % to 9 % at various flow regimes. Check for Epps-Pally criterion has showed that the sample data is not in conflict with a normal distribution law of probabilities.An assumption was made about inexpediency of calculations of the result volume flow on the basis of the vortex shedding instantaneous frequency. It is shown that the estimate of the vortex shedding frequency derived from the processing of the measurements sequence should be used in flow calculation.