Numerical Study on Two-Phase Flow in Elbow and Blind-Tee Pipes

Elbow pipes are widely used in the oil and gas industries. When the gas-liquid two-phase fluid flows through the elbow pipes, complex flow patterns may occur and affect the regular operation of the pipeline. Considering that the blind tee can promote the flow mixing condition, it is applied as the bending structure of two-phase transportation pipelines to compare with the traditional elbow in this study. The computational fluid dynamics method is used to compare the flow characteristics inside the elbow pipe and blind tee under 50% water content. The results show that the blind tee has a better effect on the gas-liquid flow mixing than the traditional elbow. Due to the fluid exchange between the mainstream and the backflow from the blind section, the mixing condition of gas and liquid is improved, making it possible to inhibit the generation of slugs in the downstream pipe. Besides, the flow conditions inside the blind tee are compared under different water contents to analyze the effect of the gas-liquid ratio. It provides references for the safe and stable operation of offshore pipelines.