Experimental investigation on the initiation and flow development of gas-liquid slug two-phase flow in a horizontal pipe

As a result, several basic mechanisms of slug flow initiation in a horizontal pipe were clarified. Those were the wave coalescences, the wave growth mechanism, and the large disturbance waves. A flow initiation map was proposed to address those mechanisms. Here, the slug initiation frequency and the passing slug frequency were obtained in relation to the pipe length position. The static pressure measurement was also used to verify the image processing results on the characteristics of slug initiation mechanisms. The obtained qualitative and quantitative results from the investigation can be used to evaluate the recent available models.