Experimental Investigation of a New Series of Planing Hulls

Abstract

In reviewing the state-of-the-art in planing hull testing it was observed that the hulls tested cannot be considered representative of the modem high-speed Small Craft. This is because the length-beam ratio is too high for modem forms, the deadrise angle is not varied systematically, and some series use dated or prismatic forms. A data base was generated containing general information from several hundred recently-built boats in a length range from 15 to 85 feet and a displacement range of 1,000 to 150,000 lbs. The lines of several boats have been studied to determine shape parameters for the parent hull and ranges to be covered by a series which has been developed in this research. The series consists of 9 models with a systematic variation of the length-beam ratio from 2.5 to 3.5 and deadrise angle from 12° to 24°. Weight displacements and L(cg) location are as well varied systematically resulting in a total of 210 test conditions for the series at 10 speeds each. The towing tank performance and instrumentation were validated by testing a hull previously tested at another towing tank under the same conditions. All the conditions tested are presented in tabular and graphical forms and recommendations for future research are also made.