The response of Coriolis flowmeters to pulsating flows

Generally current models of Coriolis flowmeters have a very limited dynamic response. This paper presents work which investigates the dynamic response of the meter flow tube alone (i.e. by-passing the flow transmitter) to flow pulsations. Because the shortest time for which all estimate of the phase difference call be achieved appears to be the period of one drive cycle, Pulsations at frequencies somewhat lower than the meter drive frequency were investigated. Our existing signal processing-algorithms were used to determine phase differences front sensor signals (or pseudo-signals) generated from three different Sources: firstly, pseudo-data generated from Our previously developed theoretical model of a straight tube meter response to pulsations secondly. pseudo-data produced by finite element simulations of flow tubes with complex geometries. following validation against the straight tube theoretical results: finally. experimental data obtained by recording the internal sensor signals from eight commercially available flowmeters. Results from these three Sources showed a high degree of consistency and confirmed the capability of meter flow tubes to reveal both the amplitude and reasonable definition of the waveform of flow pulsations. All meters tested experimentally showed a significant component of sensor signal noise at the Coriolis frequency. The results indicate that with appropriate flow tube design and improved meter drive and signal processing procedures, a high dynamic performance Coriolis meter is achievable. (C) 2004 Elsevier Ltd. All rights reserved.