Comparative Performance Analysis of a Jet and Screw Propulsion System

Abstract

This study presents a comparative performance analysis of the jet and screw propulsion (JSP) systems, whichutilized mathematical and simulation-based models of the JSP systems analyses, compares the thrust generationof JSP systems under varying speed conditions (from 5 m/s to 25 m/s) and analyzed the fuel efficiency of the JSPsystems across different operational scenarios The simulation incorporated hydrodynamic parameters such asmass flow rate, jet velocity, propeller diameter, thrust coefficient, and fuel mass flow rate. Results show that whileboth propulsion systems generated substantial thrust across all speed regimes, the screw propulsion systemconsistently outperformed the jet system in thrust generation and efficiency. At the highest ship speed of 25 m/s,the screw propulsion achieved a thrust of 29,343 N compared to 10,500 N for the jet system. The specific fuelconsumption (SFC) of the screw system ranged from 4.42 g/kN·s to 0.88 g/kN·s, markedly lower than the jetsystem’s 48 g/kN·s to 9.6 g/kN·s, indicating approximately 11-fold greater fuel efficiency. Similarly, screwpropulsion maintained a consistently higher propulsive efficiency, while the jet system improved from 0.14 to0.36 with increasing speed. The study concludes that screw propulsion provides superior thrust and fuel economyacross all tested speeds, making it better suited for general marine operations. In contrast, jet propulsion offersadvantages primarily in high-speed or specialized hydrodynamic applications. The research contributes topropulsion performance literature by providing validated comparative metrics and highlighting efficiencystability relationships crucial for system selection and optimization in marine engineering.