Large-scale simulations for maneuvering submarines and propulsors

This paper describes an emerging computational capability for physics—based flow simulation and maneuvering predictions for appended submarine/propulsor geometries. The solution methodology for the unsteady Reynolds-averaged Navier—Stokes equations is summarized, including the transition of this capability from single—processor to scalable parallel computing. The current status of validation efforts for this methodology is discussed, including comparisons for appended—hull force and moment coefficients andpropulsor thrust and torque coefficients. Results are given from several simulations related to maneuvering of appended submarines with rotating propulsors. This capability will enable new complex simulations in computational naval hydrodynamics that can support the submarine design process as well as provide understanding leading to improved safety margins in submarines undergoing complicated maneuvers. To illustrate the impact of the scalable parallel code, a submarine maneuver requiring 3 million grid points and covering a distance of five hull lengths can be run in less than two days on 80 T3Eprocessors, as compared with over four months on a single processor.