Optimisation scheme applied to the Voith-Schneider propulsion system using genetic algorithm

This paper is presented to calculate the hydrodynamic characteristics of the Voith-Schneider Propeller (VSP) and its optimisation scheme applied to the vessels using genetic algorithm (GA). VSP is an efficient propulsion system in manoeuvring of service vessels such as tugs, offshore vessels, workboats and some other vessels. In this study, hydrodynamic forces of thrust and torque are considered as objective functions, whereas four geometrical parameters of VSP, i.e. disk radius (R), chord (c), span (b) and pitch ratio (e), are considered as variables. A simple GA optimisation scheme is applied to the VSP system to find the optimum values of the VSP parameters to achieve the highest efficiency, in which the thrust and torque are calculated through the practical formulas. The calculated results of the open-water characteristics at various geometrical parameters are presented and validated against experimental data. Finally, the optimisation scheme is applied to two VSP systems employed for two vessels of Voith Water Tractors (VWT) and Offshore Support Vessels (OSV). The optimisation results showed that the efficiency of VSP improved by 6.2% and 1.6% for OSV and VWT vessels, respectively.