Dynamics of two-phase flow analyzed by multi-gate correlations

A multi-gate cross-correlation technique is applied to analyze the dynamics of a two-phase flow. The water and air concurrent flows are measured in a 5 mm diameter circular channel inclined at an angle of 45 degrees and set vertically, with different gas-to-liquid volume rates. The Experimental results are put in series with a constant water flow rate. Several variables are measured along with capturing video frames by a fast digital camera. Time-series data are extracted from the video data by setting seven conversion gates in the camera's field of view. By calculation of the cross-correlation coefficients between the first and subsequent gates, the characteristic parameters of spatial correlation decay are measured for each flow. A comparison of the correlation decay in the modeled and experimental flows reveals some interesting aspects of the flow dynamics.