Numerical Investigation on Near-bottom Operation of an Extra-large Freight Submarine

Abstract

Abstract This work investigates the hydrodynamic performance of a subsea shuttle, an extra-large freight submarine, during near-seabed operation. The three-dimensional Reynolds-Averaged Navier-Stokes method combined with the k-υ shear stress transport (SST) model is used to predict the pressure, skin friction, drag, and lift forces acting on the subsea shuttle. The present numerical model is verified and validated against the experimental and numerical data from the SUBOFF-1 project, a standard submarine model developed by the Defence Advanced Research Projects Agency. Two operational scenarios are considered in this study: (1) the subsea shuttle traveling near the seabed with a forward speed; (2) the subsea shuttle hovering close to the seabed and subject to an incoming current flow. A representative seabed boundary layer profile is considered in the analyses. A fully developed boundary layer profile is generated using one-dimensional simulations and implemented as the inlet boundary condition in the 3D simulations. The effects of the gap ratio between the subsea shuttle and the seabed, and the inflow speed of the boundary layer flow on the hydrodynamic properties of the subsea shuttle are evaluated and discussed in detail.