The propeller cavitation inception speed (CIS) is very important to the stealth performance of a naval vessel. Propeller cavitation is heavily influenced by the hull and its appendages. Most warships have struts (I-shaped or V-shaped) to support the propeller inclined shaft. Because these appendages are installed in front of the propeller, they have a great influence on propeller cavitation inception. However, since the strut has been designed in terms of the propulsion performance of the ship, it is necessary to study how it affects propeller cavitation.
In this study, the effect of the flow according to the alignment of the struts was investigated. Based on the numerical analysis results, the optimal alignment angle of the strut was derived. Wake distribution measurement and propeller CIS test were performed in a large cavitation tunnel to verify the design method.
Model tests showed propeller CIS performance improvement of up to 2.6 knots by adjusting only the strut angle. The proposed method will be usefully utilized as a ship strut design technique for improving the propeller CIS performance in the future.