3 4 5 6 Blades Fixed Pitch Propeller FPP Marine Ship Vessel Bulk Tanker Tugboat Propeller Hub

Specification

Propeller

A propeller is a device that relies on blades to rotate in air or water to convert the rotational power of the engine into propulsion. There can be two or more blades on the hub, and the back side of the blades is a spiral surface or a spiral surface. propeller. There are many types of propellers and are widely used, such as propellers for airplanes and ships.

Side Thruster

Side thruster refers to a device that assists the ship's steering. Generally, it is a propeller driven by an electric motor in the transverse pipe of the bow, which can discharge water on one side to the other side, and assist the steering of the ship by the reaction force of the water. When the ship leaves, docks or sails at low speed, the rudder has little effect, and the thruster can improve the maneuverability of the ship. Some are equipped with side pushers at the bow and stern to move the ship laterally or steer on the spot.

Geometric parameters

Actual pitch (Hg)

The distance traveled by the aircraft in one revolution of the blades. Hg=v/n can be used to calculate the actual pitch value of the propeller. The value of the geometrical pitch of the propeller used by the aircraft can be roughly estimated according to H=1.1～1.3Hg.

Theoretical screw moment (HT)

When designing the propeller, it must be considered that the speed of the air flowing through the propeller increases, and the airflow speed flowing through the rotating plane of the propeller is greater than the flight speed. Therefore, the theoretical pitch of the propeller relative to the air will be greater than the actual pitch.

Picture

Pull change

Change with speed

When the flight speed is constant, the tangential speed (U) increases when the speed increases, the pitch ratio decreases, the angle of attack of the blade increases, and the propeller pull coefficient increases because the pull is proportional to the square of the speed, so it increases. At high throttle, the pulling force can be increased.

Change with speed

In the case of constant speed, the flight speed increases, the pitch ratio increases, the blade angle of attack decreases, and the propeller pull coefficient decreases. , The pulling force decreases accordingly. When the flight speed is equal to zero, the tangential speed is the resultant speed, and the blade angle of attack is equal to the blade angle. When the aircraft is on the ground, the flight speed (V) is equal to zero, and the angle of attack of the blades is the largest. In some profiles, the aerodynamic performance of the propellers is not necessarily the maximum because the angle of attack is too large to exceed the stall angle of attack.