Wake of a cruciform appendage on a generic submarine at 10∘ yaw

• Published in: Journal of marine science and technology Vol. 25; no. 3; pp. 787 - 799
• Main Authors: Lee, S.-K., Manovski, P., Kumar, C.
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01.09.2020; Springer; Springer Nature B.V
• Subjects: Analysis; Automotive Engineering; Computational fluid dynamics; Engineering; Engineering Design; Engineering Fluid Dynamics; Fluid flow; Image resolution; Iterative methods; Kaolinite; Mechanical Engineering; Offshore Engineering; Original Article; Particle image velocimetry; Reynolds number; Sails; Submarine boats; Tracking; Vortices; Wind; Wind tunnel testing; Wind tunnels; Yaw; Yawing; Flow visualisation; Particle image velocimetry; Wind-tunnel testing; Generic submarine
• ISSN: 0948-4280; 1437-8213
• DOI: 10.1007/s00773-019-00680-x

The present model geometry is a recent iteration of the Joubert (Defence Science and Technology, Tech. Rep. TR-1920, 2006) generic conventional submarine design and is known as the “BB2”. Wind-tunnel testing of the model at 10 ∘ yaw, by China-clay visualisation and by ensemble-averaged measurements using high-resolution stereoscopic particle image velocimetry, shows a similar wake flow at the model-length Reynolds numbers R e L = 4 × 10 6 and 8 × 10 6 . The most significant flow feature is on the model upper hull. It is a system of three co-rotating vortices produced by a cruciform appendage which consists of a vertical fin (or sail in American terminology) and two horizontal hydroplanes. Circulation is strongest from the fin tip followed by the windward hydroplane, then the leeward hydroplane. Vortex tracking shows a down-wash of the fin-tip vortex, where the wind-ward- and lee-ward-hydroplane vortices spiral in the rotation direction of the fin-tip vortex. The interpreted flow includes a U-shaped vortex line around the leeward hydroplane, where this vortex line connects the fin-tip vortex and a surface vortex on the leeward side of the fin.