Numerical Simulation of Flow around Subsea Covers at High Reynolds Numbers

Abstract

Glass Reinforced Plastic (GRP) covers are widely used to protect the subsea equipment from external damage. In this work, numerical simulations of a fully developed turbulent boundary layer flow over square and trapezoidal wall-mounted GRP covers are performed using a open source tool: OpenFOAM. The aim of this master thesis is to evaluate the effect on flow characteristics from the shape of the structure, the boundary layer thickness and the Reynolds number. The trapezoidal obstacles with different slope angles are under investigation. Hydrodynamic quantities of turbulent boundary layer flow with various boundary layer thicknesses (𝛿���/𝐷���=0.73, 1.96 and 2.52) are examined. The structures are subjected into turbulent flows at Reynolds numbers of 0.5 × 106, 1 × 106 and 2 × 106 according to the free stream velocity and dimension of structures. Three classes of mesh sets were conducted in OpenFOAM supported mesh tool, GMSH. Two- dimensional Reynolds-averaged Navier-Stokes (RANS) equations are solved by 𝑘��� − 𝜔��� Shear Stress Transport ( 𝑘��� − 𝜔��� SST) turbulence model. The square cylinder geometry with characteristic length D has been investigated to validate the capability of RANS 𝑘��� − 𝜔��� SST model. The obtained results in present study show good agreements with previously published experiment data. The results of the streamlines, pressure and velocity distributions were also analyzed for different geometries.