Marine Common Thruster
The structure is simple, and the efficiency is generally higher at low speeds.
Energy loss for common propeller propulsion:
1. A loss of axially induced velocity occurs. When the propeller works as a propeller, this loss cannot be completely avoided, but appropriate measures can be used to minimize this loss. Generally, the value of this loss will increase as the propeller load factor increases.
2. The loss of circumferentially induced velocity, or water flow torsional loss, will also increase with the increase of the propeller load coefficient.
3. The loss caused by the viscous friction between the blade and water during operation, or called the section resistance loss.
The propeller interacts with the aircraft body, that is, the resistance loss of the propeller attachment.
Measures to reduce energy loss:
1. In order to reduce the induced loss, a propeller with a larger diameter can be used, but the section resistance loss will be increased.
2. In order to reduce the torsional loss of water flow, special diversion equipment can be used, such as: reaction rudder, rudder thrust fin and streamlined rudder, etc., to reduce wake rotation, recover wake energy, and achieve the purpose of improving propulsion efficiency.
3. In order to reduce the loss of section resistance, attention must be paid to the selection of the shape of the blade section. In the theoretical design, reasonable selection of blade width, blade thickness ratio and section shape can minimize the loss of section resistance.
Reasonable cooperation between the propeller and the hull and appendages can not only reduce the thrust deduction fraction and make more effective use of wake energy, but also improve the efficiency of the propeller itself.