Numerical Simulation Of Oil-Gas Two Phase Flow Characteristics In Elbow

By analyzing the flow characteristics of gas-liquid two-phase flow model,the mixed model is selected as the model to simulate gas-liquid two-phase flow in pipeline.The steady-state algorithm and implicit separation algorithm are used to simulate the flow pattern in the elbow pipe.The results are as follows1.With the gas-liquid two-phase flow in the pipe,the pressure in the inlet section is smaller,and the pressure in the lower side of the middle section is larger than that in the upper side,which provides power for the oblique upward flow of the fluid.The pressure is lower in the outlet section.With the increase of gas content,the gas carrying effect increases gradually.Under the condition of 60% and 80% gas content,the liquid forms wave flow.2.At the elbow,due to the different density,when the air content is less than 40%,the liquid accumulates at the horizontal,when the air content is more than 40%,the liquid flows upward in a circular direction,and the velocity increases along the Y direction at the outlet,and the turbulence intensity increases.The results show that the liquid flows upward along the lower side of the inclined pipe and the gas flows upward along the upper side of the elbow.With the different gas content,the gas flow ratio increases gradually.3.When the flow rate is constant,with the increase of the elbow angle,the velocity of the mixed fluid decreases,the flow pattern changes,the angle increases,the gas velocity increases,and the carrying effect increases.In the liquid flow area,the gas carrying liquid flows upward along the elbow.With the increase of the gas content,there is backflow at the elbow.When the gas content is small,the density difference is small,the gas content increases,and the liquid flow rate increases The flow velocity is the lowest in the middle section of inclined pipe.