Simulation of an unappended axisymmetric submarine hull during unsteady pitching

Abstract eng:
Unsteady CFD simulations of the unappended DARPA SUBOFF 5470 undergoing a pitch maneuver were conducted using Ansys CFX to support the development of hydrodynamic force models for simulating the transient dynamics of underwater vehicles. The simulations used a sliding mesh formulation and the BSL Reynolds stress turbulence model. Four simulations were conducted with varying pitch rates; the results from two of these were compared to experimental wind tunnel tests. The simulated flow was qualitatively correct, however comparisons show that the simulations under-predict the normal force and over-predict the pitching moment. This error grows in proportion to the angle of incidence. The body-normal vorticity moment distribution along the body and wake was calculated, and is seen to transition between from a steady translation distribution to a steady rotation distribution over the maneuver. This transition appears to be proportional to the local drift angle along the hull and the pitch rate.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket