Flow regime is one of the fundamental elements to describe gas-liquid two-phase flow system. It is of great importance in research as well as engineering application of gas－liquid two-phase flow to determine flow regimes correctly. Therefore the recognition of flow regime is one important aspect in the field of two-phase flow research. Based on the summary of the studies on the regime determination in domestically and overseas, following two aspects of work results were presented in this report. First, the new methods in gas-liquid two-phase pipe flow regime on-line recognition based on the processing of pressure fluctuations inner the pipe and pressure drop fluctuations along the pipe; second, the characteristics of Non-Newtonian two-phase pipe flow regime. Followings are main results of our work: 1) A review and summary on the definition, flow regime maps, transition criteria, online recognition methods were presented in detail. 2) It was investigated that the method of extracting features of flow regime by using power spectrum density distribution (PSD) of pressure drops fluctuations along the pipe. Features of 4 different typical low regimes in horizontal gas-liquid two-phase pipe flow were also given; 3) Based on the results of normalized cross-correlation processing of two pressure signals which were adopted from different locations in the flow pipe, a new flow regime recognition method was presented; 4) It was also presented to recognize flow regimes by using the pressure signal transfer function's aptitude-frequency characteristics within a pipe section; 5) Based on experimental investigations, the comparison of the flow regime occurrence conditions and features related to gas/power-number fluid two-phase horizontal pipe flow to that of in air-water two-phase horizontal pipe flow, and the gas/power-number fluid two-phase horizontal pipe flow regime map were presented; 6) The flow regime occurrence conditions, flow regime maps and their features related to gas/power-number fluid two-phase upward slant pipe flow were also presented; 7) The dynamic characteristics and errors of pressure drop measurement system were studied and the method of dynamic common-mode error repression was promoted. Advice related to future research work was also suggested in this report.
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