Propulsion and propellers

The propeller is mounted on the tail of the hull and consists of a few blades and a hub. The hub is a truncated cone that is connected to the tail shaft to transfer the load. The propeller blade is a typical curved surface part with a helical surface shape, which is determined by the value of a series of cylindrical sections. All blades are fixed and distributed around the hub, forming overlapping relationships in space. In general, a fairing (that is, a hub cap) is mounted on the rear end of the hub, which forms a streamlined body with the hub to reduce water resistance. The side of the propeller blade seen from the rear of the ship is called the pressure surface, and the other side is called the suction surface. When the propeller is rotating, the edge of the blade first entered the water is called the leading edge, and the other side is called the trailing edge.