Non-dimensional waterjet performance curves for the propulsion matching of planing craft

Abstract: This paper presents a general performance prediction technique for a successful selection of a waterjet unit in planing craft propulsion. The developed procedure is based on a complete physical approach, from which a set of non-dimensional waterjet characteristics has been drawn, on the analogy of the well-known propeller series. In particular the paper describes the hypotheses, the genesis, the tuning and the application of this general systematic waterjet curves for planing craft. The systematic knowledge of the waterjet performance and cavitation characteristics should overcome the design limitations associated with the use of the traditional “Thrust-Resistance” graphical maps, usually provided by jets manufacturers. The aim of this work is to give a useful and reliable tool to the naval architect, introduced in a familiar form for him, able to make the solution of waterjet propulsion matching problem a numerically simple task.