NUMERICAL SI MULATION OF MOVING SCOUR BOUNDARY AND TURBULENCE FLOWAROUND SUBMARINE PIPELINES

A two dimensional vertical mathematical model is proposed in this paper for simu lating the equilibrium profile of local scour around submarine pipelines. The cu rrent model is composed of a new k-ε turbulence model, fitting moving bo undary with pre-meshed grid lines and incipient criterion of shear stress for s ediments. Employing the proposed model, an instance is carried out numerically a nd compared with experiments. The calculation results agree well with the experi ments. It shows that the improved two-equation turbulence model adopted in this paper is appropriate to simulating the turbulent flow field around submarine pi pelines, fitting moving boundary with pre-meshed grid lines method is efficient for moving boundary problems in a multiply-connected domain and the stability evaluation method for seabed with critical shear stress based on log-wall law i s a reliable choice.