A complete design of ship propellers using the new computer system
The computer system presented in this article is composed of several program blocks for the complete design of ship propellers. The design calculations are based on a combination of the modified lifting line theory and on the vortex lifting surface theory. The system enables solution of the following design problems:
- calculation of the scale effect on the ship wake velocity field, including the influence of the propeller and rudder on this field at the propeller location
- maximization of the propulsive efficiency
- optimization of the propeller blade geometry on the basis of the compromise between the cavitation and blade strength requirements
- optimization of the number of propeller blades and blade geometry on the basis of the acceptable level of induced pressure pulses and unsteady shaft bearing forces
- calculation of the blade spindle torque for the controllable pitch propellers.
The computer system is equipped with many numerical options for graphical visualization of the input data, including an easy possibility of their correction and control of the intermediate and final results of calculations.