A method based on potential theory for calculating air cavity formation of an air cavity resistance reduction ship

Abstract

This research is intended to provide academic reference and design guidance for further studies to determine the most effective means to reduce a ship's resistance through an air-cavity. On the basis of potential theory and on the assumption of an ideal and irrotational fluid, this paper drives a method for calculating air cavity formation using slender ship theory then points out the parameters directly related to the formation of air cavities and their interrelationships. Simulations showed that the formation of an air cavity is affected by cavitation number, velocity, groove geometry and groove size. When the ship's velocity and groove structure are given, the cavitation number must be within range to form a steady air cavity. The interface between air and water forms a wave shape and could be adjusted by an air injection system.

Flow dynamics in the closure region of an internal ship air cavity

“…One approach is to apply this framework in conjunction with other assumptions, which allows deriving approximate expressions for certain properties of the cavity that can be very useful in the initial phase of design. Of particular relevance for this work is the study by Matveev regarding wave properties of internal air cavities (Matveev, 2007), but see also (Li et al, 2008;Matveev, 2003). Potential flow theory can also be used as basis for purely numerical predictions, see (Matveev, 2012(Matveev, , 2015Matveev et al, 2009).…”