Effect of System Pressure on Liquid Film Behavior in Horizontal Annular Flow

The measurement of liquid film parameters is of great significance in the momentum transfer and heat transfer characteristics of gas-liquid two-phase in annular flow. The liquid film at the bottom of the horizontal annular flow is the thickest and produces the greatest influence on the nature of the annular flow. In large diameter horizontal pipes, the effect of pressure on liquid film behavior lacks systematic discussion. Therefore, a dynamic measurement system for annular flow liquid film was designed based on near-infrared(NIR) sensing technology to complete the measurement of annular flow liquid film thickness data under five pressures. The average liquid film thickness at the bottom is obtained by variational modal decomposition(VMD) of the time series signal, and the wave velocity parameter is obtained by mutual correlation velocimetry. The article initially discusses the effect of pressure on the average thickness of the bottom liquid film as well as the interfacial wave velocity.