Parallel Simulation of a Marine Riser Using MPI

Abstract

In this paper the dynamic response of a marine riser due to vortex shedding is numerically investigated. The riser is divided in two-dimensional sections along the riser length. The Discrete Vortex Method is employed for the assessment of the hydrodynamic forces acting on these two-dimensional sections. The hydrodynamic sections are solved independently, and the coupling among the sections is taken into account by the solution of the structure in the time domain by the Finite Element Method. Parallel processing is employed to improve the performance of the method. The simulations are carried out in a cluster of Pentium IV computers running the Linux operating system. A master-slave approach via MPI — Message Passing Interface — is used to exploit the parallelism of the present code. The riser sections are equally divided among the nodes of the cluster. Each node solves the hydrodynamic sections assigned to it. The forces acting on the sections are then passed to the master processor, which is responsible for the calculation of the displacement of the whole structure. Scalability of the algorithm is shown and discussed.