Exam Question

(a) How a propeller produces thrust:
A ship's propeller generates thrust by rotating its blades, which displace water. This displacement creates a void, causing water to rush in and fill the space. This movement results in a pressure difference. Water accelerates from the front of the propeller blades to the back, forming a column of water slightly larger than the propeller itself. The increased velocity creates a water jet behind the propeller. This jet adds momentum and thrust to the water, propelling the vessel forward.
(b) How producing thrust may lead to propeller cavitation:
Cavitation occurs when the local pressure in the liquid drops below the saturated vapor pressure of water, leading to the formation of vapor bubbles. When producing thrust: