CAVITATION DIAGRAMS FOR MERCHANT SHIPS USING FOUR BLADE B SERIES PROPELLERS

Abstract

Propeller cavitation in seagoing merchant ships is sensitive to main dimensions and form coefficients variation and has substantial influence on the choice of hull shape. Main parameter (L,B,T,C_B,D_prop) optimization in the beginning phases of design is a challenging task since propeller calculation for only a single chosen hull form requires a series of extensive ship calculations beforehand, which implies that getting a clear picture of parameter influence on the cavitation occurrence is hard or even impossible without systematic parameter variation and numerous repetitions of these calculations. Optimal four blade Wageningen B-Series propellers were calculated for a database of hull forms with systematically varied parameters and for a range of speeds. The Burrill criterion was then used to exclude the cases in which cavitation occurs and create diagrams for choosing the main hull parameters in the early design phase to avoid cavitation.