Numerical Simulation of the Hydrodynamic Performance and Self-Propulsion of a UUV near the Seabed

Abstract

Unmanned underwater vehicles (UUV) face maneuverability and rapidity challenges when they are applied for detecting and repairing submarine oil and gas pipelines, and fiber cables near the seabed. This research establishes numerical models of the bare UUV and self-propelled UUV near the seabed using the computational fluid dynamics (CFD) method. The effect of dimensionless distance Hd and ReL on the hydrodynamic performance of the vehicle and the interaction between the hull and the propeller is investigated. The range of Hd is 1.5D–10D, and the ReL is 9.97 × 105~7.98 × 106. Findings indicate that: (1) There is an obvious strong coupling between the hydrodynamic performance of the bare UUV and Hd. With the increase of Hd, the hydrodynamic performance such as Cd, the absolute value of Cl and my decreases continuously and finally tends to be stable. The absolute values of Cd and Cl increase with the increase of ReL. The change trend of my is opposite to that of Cl. (2) The variation trend of hydrodynamic performance of the self-propelled UUV with Hd is consistent with those of the bare UUV. Additionally, it increases to some extent, respectively, compared with the bare UUV. (3) The self-propelled characteristics such as t, ηH, w and ηi are weakly related to Hd. The t and ηi increase with the increasing of ReL, while ηH and w decrease with the increasing of ReL.