Horizontal Evolution of Intermittent Gas- Liquid Flows with Highly Viscous Phases

Experimental work on high viscosity two-phase flows is presented. Newtonian mixtures were produced by simultaneously injecting Glycerine, with dynamic viscosity of 1.2 Pa.s (1,200 cP), and air. Then, the analysed flow developed in a horizontal pipe with a length-to-diameter ratio L/d=500. Various combinations of gas and liquid flow rates were considered within the respective ranges 1.66 (1.66×10⁻³≤qg≤3.33×10⁻³)m³/s, and (0.125×10−3≤ql≤0.785×10−3)m³/s. The experiments show that only intermittent flow patterns can be produced with the flow rates under consideration. Furthermore, a preliminary comparison with some well-known correlations suggests that the typical methods could yield inadequate predictions of the flow properties. Therefore, an alternative analysis based on the spectral content of the pressures is considered. This method allows for a proper characterization of a given flow in terms of its unique spectral 'footprint', which globally condenses all aspects of the underlying dynamics.