Development of a standard range of waterjets for vessels with high seakeeping performance

Abstract

Object and purpose of research. The object of the research is a fundamentally new waterjet, intended for installation on ships of increased seakeeping performance with discrete-variable bottom deadrise. The purpose of the research is to develop and experimentally test the impeller and water duct for a variety of waterjet design possible for installation aboard vessels with large deadrise operating in severe weather conditions.
 Materials and methods. Test data for waterjet impellers obtained at KSRC Cavitation Tunnel for Special Propulsors.
 Main results. The study made it possible to select optimal impeller geometry and develop the shapes for water inlets and water ducts of three waterjet designs with partial-pressure water inlets: two waterjets with isolated single-elbow water ducts and inlets on the bottom section with medium deadrise, "II"design; two waterjets with combined water duct and inlets on the bottom section with maximum deadrise and double jet, “X” design; single waterjet with bifurcating two-elbow water duct and a pair of water inlets on the bottom section with maximum deadrise, “Y” design.
 Conclusion. The studies have shown that developed waterjet impeller features good hydrodynamic and cavitation characteristics, and possible air suction creates a smooth, rather than sharp, force decrease.