Design and Optimization of an Ice Class Propeller Under Shallow Water, Semi-Tunnel Hull and Heavy Load Conditions

A design and optimization procedure developed and used for a propeller installed on a twin-semi-tunnel-hull ship navigating in very shallow and icy water under heavy load conditions is presented. The base propeller was first determined using classical design routines under open water condition utilizing existing model test data. In the optimization process, a panel method code (PROPELLA) was used to vary the pitch values and distributions and take into account the inflow wake distribution, tunnel gap and cavitation effects. The optimized propeller was able to numerically achieve a ship speed 0.02 knots higher than the desired speed and 0.06 knots higher than the classical B-series propeller. The analysis of the effect of inflow wake, hull tunnel, cavitation and blade rake angle on propulsive performance will be the focus of this paper.