Farfield waves created by a monohull ship in shallow water

摘要

Interference effects between the dominant waves created by the bow and the stern of a monohull ship, of length L, that advances at constant speed V along a straight path in calm water of uniform Finite depth D are considered. The largest waves due to constructive interference result in an apparent wake angle psi(max), that can differ greatly from the cusp or asymptote angles associated with the wave pattern of a ship when interference effects are ignored, as in Kelvin's classical analysis. Thus, wave interference has a very large effect on the wave signature of a ship in shallow water and cannot be ignored. Water-depth effects on the wake angle psi(max) are found to be insignificant for water depths d(L) equivalent to D/L greater than d(deep)(L) approximate to 0.89 or for Froude numbers F equivalent to V/root gL greater than F-deep approximate to 0.5/root d(L). Furthermore, the water depth d(L) has only a relatively small influence on the wake angle psi(max) for 1.5 < F, and the deep-water approximation psi(max) approximate to 0.14/F-2 can then be used. (C) 2014 Elsevier Masson SAS. All rights reserved.