Micro-bubble resistance reduction on a model SES catamaran

The concept of micro-bubble ejection is emerging as an attractive method for viscous drag reduction for high speed craft. Most of the drag reduction literature presents results for microbubble ejection above/below horizontal surfaces. Nevertheless, modem high-speed hull forms are slender with vertical surfaces. This paper presents results of model tests with micro-bubble ejection to the vertical sides of a high speed model with a non-wetting coating. The coating yielded drag reduction of 4-6% and micro-bubbles with coating reduced overall drag by 411 %. The local coefficient of friction with micro-bubbles is analyzed and found comparable to vertical flat plate results of Madavan et al. (1984). (C) 2003 Elsevier Ltd. All rights reserved.