Measurements on dispersion of pressure wave in gas-liquid two-phase flow

An experimental setup for gas-liquid two-phase flow has been designed, which can adjust the disturbed frequency of the pressure force acting on the piping flow without mass transfer. Experiments on the dispersion characteristics have been performed in vertical upward gas-liquid bubble flow and slug flow through a transparent pipe system under atmospheric pressure. Both pressure wave speed and attenuation were measured under different disturbed frequency with pressure transducers mounted flush to the pipe wall. In the bubbly flow, the results show that both the pressure wave speed and attenuation have close relation with the disturbed frequency. Both the wave speed and the attenuation increase with the disturbed frequency. However, the flow velocity of the two-phase fluid has no effect on the dispersion of pressure wave. Based on the experiment and the numerical simulation in reference [1], a new phenomenon is validated that the dispersion of pressure wave will disappear under the perturbation frequency greater than a critical frequency. And the physical mechanism of this new phenomenon is analyzed in the study. The pressure wave in the slug flow has also the feature of dispersion, but there are still no correlations to predict it.