Multi-mode adaptive-pitch propeller and its efficiency in coaxial contrarotating propeller systems

Abstract

Object and purpose of research. This paper discusses possible applications of multi-mode adaptive-pitch propeller in coaxial contra-rotating propeller systems. The study compares efficiency calculation results for these propellers and their conventional FPP counterparts. The authors also give a design calculation layout for coaxial propellers as per hydrodynamic test diagrams for solitary FPPs, as well as demonstrate their hydrodynamic calculation. Calculation results confirm that multimode adaptive-pitch propellers may considerably increase the efficiency of a coaxial propeller system in high-load conditions. The study also demonstrates that coaxial propeller systems have greater efficiency also when they are made up by solitary FPPs. These results might be useful in practical design of various ships. Subject matter and methods. The study relies on hydrodynamic test data for solitary FPPs and gives layouts for design and verification calculations of coaxial propeller systems. Main results. These data could be used to estimate the efficiency of coaxial propulsion for given ship design. Conclusion. The study shows that multi-mode adaptive pitch propeller tend to increase overall efficiency of coaxial propeller systems in high-load conditions as compared to FPPs.

Keywords

• multi-mode adaptive-pitch propeller
• high-load conditions
• moderate-load conditions
• propulsion efficiency