On Ripple of Annular Two-Phase Flow : 1. Statistical Characteristics of Ripples

A statistical method is proposed to express the gas-liquid interface on a lot of waves existing in the ripple regimen of upward two-phase annular flow. Experiments were made to establish the present method on local liquid holdup and probability density of wave to its height. It was found that the probability density of wave conforms to log-normal distribution and the crest of wave becomes sharp as flow regime shifts from ripple to disturbance wave.