Correlation of Prototype and Model-Scale Wave Wake Characteristics of a Catamaran

Abstract

This paper summarizes an experimental investigation into the correlation of model-scale wave wake measurements against full-scale trial results for a 24-meter long catamaran operating over a range of length Froude numbers. Both full-scale and 1/15th-scale model experiments were conducted over the range of length Froude numbers of approximately 0.3 to 1.0 (full-scale speed range of 6 to 28 knots). The water depth during the experiments was approximately 12 meters, with corresponding depth Froude numbers ranging from subcritical (~0.3), through a transcritical range (~0.8 to 1.1) into low supercritical speeds (up to ~1.3). The results of the investigation confirm that a correlation factor of close to unity be applied when using model-scale experimental data to predict the full-scale height and period of the maximum wave generated by similar catamarans operating within such speed ranges. Consequently, it is expected that the energy of the maximum waves can also be accurately predicted from model-scale data. This paper also provides useful guidance notes for the conduct of full-scale wave wake experiments and highlights some issues regarding the identification of the maximum wave(s) generated when vessels operate at trans and/or supercritical depth Froude numbers.