Fluid–structure interaction computational analysis of flow field, shear stress distribution and deformation of three-limb pipe

As a vulnerable component of piping systems, three-limb pipe usually fails due to flow erosion or deformation. In this study, computational fluid dynamic (CFD) models and a fluid–structure interaction computational method are used to investigate the flow erosion and flow induced deformation of a three-limb pipe used in oil transportation. The flow characteristics of oil flow including pressure and velocity distribution are captured based on calculating three-dimensional Reynolds-Averaged Navier–Stokes (RANS) equations. And realizable k–ε turbulence model is applied to model the turbulence. The effects of branch inlet flow rate, diameter ratio of branch and main tubes and merging angle of three-limb pipe on flow characteristics, shear stress distribution and deformation of pipe are analyzed based on a series of numerical simulations. The numerical results show that both flow field and deformation of pipe are sensitive to the structural changes and branch inlet velocity changes. Higher importing mass flow rate or 90° merging angle can lead to more severe flow erosion and greater deformation.