CFD Investigation on Secondary Flow Characteristics in Double-Curved Subsea Pipelines with Different Spatial Structures

Double-curved pipes are widely employed as essential components of subsea pipeline systems. Considering the layout flexibility and application diversity, there various spatial structures for double-curved combinations. However, few studies have compared flow characteristics in different pipes. The dissipations corresponding downstream not been thoroughly investigated, which crucial measurement accuracy assurance. In this paper, turbulent with (i.e., Z-, U-, Z- type) was numerically studied by employing ω-Reynolds stress model. major purpose to develop an in-depth knowledge on secondary quantify flow. effects angle interval distance two curves fields taken into consideration, swirl intensity Si is introduced evaluate dissipation. It found that flows U-type opposite directions when short (3D), Z-type exhibits oblique symmetric form. Only pipe a exponential dissipation, fully developed easier achieve than other cases. increases, U- same, all return types. obtained dissipation rates Z-pipes 9D were 0.40, 0.25, 0.20, respectively. results expected guide design layouts provide reference arrangements flowmeters complex system.