ALGORITHM AND INFLUENCE FACTOR STUDY ON FLOW PATTERN TRANSITION FROM STRATIFIED FLOW TO NON-STRATIFIED FLOW OF GAS-LIQUID TWO-PHASE FLOW

Based on the Viscous Kelvin-Helmholtz theory used by D. Barnea & Y. Taitel (1993), a two-fluid stratified flow model of gas-liquid two-phase flow is established. Using the mathematical derivation, the influence of various influence factors on the stability of liquid level structure is synthesized. Compared with the criteria of D Barnea & Y. Taitel (1993) and Taitel & Dukler(1976) , and the algorithm of flow pattern transition criterion of stratified flow is proposed. According to the data of multiphase flow experimental loop, the influence of liquid viscosity and the instantaneous volume flow rate change of gas-liquid two-phase on the transition criterion is analyzed. The result shows that liquid viscosity has a great influence on the stability of stratified flow. With the increase of liquid viscosity, the friction resistance and viscous force increase, and they play a role in preventing the rise of liquid level height, it is difficult to form liquid slug in the pipe, so that the region where the stratified flow exists stably is enlarged. And instantaneous change of gas-liquid flow rate has little influence on the flow pattern transition.