Parallel simulations for control-surface induced submarine maneuvers

Abstract

This paper describes recent results on the development of an improved physics-based computational method for the determination of maneuvering characteristics of fully-configured self-propelled underwater vehicles, with particular emphasis on rotating propulsors, moving appendages and eventually full-scale Reynolds numbers. The scalable parallel solution methodology is briefly described, and results are given for a turning maneuver induced by a 10 degree rudder deflection. Aaditional results are given, including validation of force coefticients for a simple appended hull using both q-o and k--E turbulence models, a notional I I.4 bladed Sirenian propulsor with q+ turbulence model, and a solution with a body-force propulsor model. These simulations demonstrate new capabilities for both design and analysis of maneuvering propelled submarines, which will contribute both predictions andnew understanding that can help improve the design and operational safety of submarines.

Parallel efficiency in implicit multiblock, multigrid simulations, with application to submarine maneuvering

“…This notional submarine does not have realistic design values for parameters such as moment of inertia, and consequently, the results demonstrate the capability for predicting maneuvers but do not represent an actual maneuver of a particular submarine. Validation comparisons given in [2] for force and moment coefficients on a simple appended hull using both q-oo and k-e turbulence models indicate a high degree of accuracy for this geometry.…”

“…Using 50 T3E-900/256Mb processors, the solution required 53.2 hours (2660 processor hours) per hull length. This same case run with a rotating propulsor would require 7000 time steps and 8000 processor hours for each hull length traveled (cf., [2]). The code typically runs at about 3.5 GFLOPS on 50 T3E processors, with only about 13% communications overhead.…”

“…In the present paper, results from a rising maneuver induced by a prescribed sailplane motion are given for the SUB OFF configuration in [2], but without a rotating propulsor. Omitting the propulsor allows significantly larger time steps and consequently reduces the runtime for each length of distance traveled.…”

“…A previous paper [2] has addressed simulations of submarine maneuvering for a fully configured SUB OFF/ propulsor configuration with realistic control-surface gaps on two sail-plane and four stern-plane surfaces. This study included a turning maneuver induced by a 10 degree rudder deflection, using a k-e turbulence model and Reynolds number of 1.2 x 10 7 .…”

“…al. [2], including a maneuvering simulation for a fully-configured SUBOFF configuration with rotating propulsor and moving control surfaces. The present study is also part of a DoD HPC Challenge Project (Purtell [3]).…”