A propulsion device for a submersible water turbine with high fuel efficiency
【Bottom view】
■Comparison table of propulsion devices
| Types of ship form | Propulsion device | Number | efficiency | high speed |
| Normal ship (mono hull) | screw propeller | １or２ | ◯ | X |
| Hydrofoil | water jet | ２or４ | X | ◯ |
| Catamaran | water jet | ２or４ | X | ◯ |
| through hull ship (kurokiship) | underwater whell | ５－９ | ◎ | ◎ |
■Propulsion device
KurokiShip employs a submersible water turbine with a wide range of ship width as a fuel-efficient propulsion device. The underwater turbine rotates in the same longitudinal direction as the traveling direction and pushes out the water from the front to the rear so that the propulsion efficiency is good. Energy efficient (fuel economy) is good because it arranges the submersible watercock in full breadth and pushes a large amount of water backward.
■Position of the water wheel
【Position of the water wheel】
The position of the wing of the submersible water propulsion device of KurokiShip is below the bottom of the ship. Place the part around the water wheel in a place where water in the space under the water channel does not collide, and push the water forward from the front. Place the part of the blade below the bottom of the ship. Even if there is a protrusion of the electric motor to be driven, it is possible to advance the ship with good propulsion efficiency by arranging the water wheels side by side in a zigzag arrangement and extruding a large amount of water below the bottom of the boat.
■Underwater wheels
【Water wheel】
The underwater turbine rotates in the same longitudinal direction as the traveling direction and pushes out the water from the front to the rear so that the propulsion efficiency is good. In the submersible watercourse, there are about 8 blades in the rotating drum, the blades scrape water from the front and extrude backward. Since the water-turbine water wheel has a shape with blades at the tip of the rotating drum, water does not enter the inside of the rotating drum, so the difference in speed between the inside and the outside of the rotating shaft decreases, and the loss due to the speed difference decreases Is good).
The screw propeller that many current ship adopt rotates in the transverse direction perpendicular to the direction of travel and pushes water forward from the front using lift force, so the propulsion efficiency is poor. Due to the shape of the screw propeller with the blades attached to the rotating shaft, the speed difference between the inside and the outside of the rotating shaft becomes large, and the loss due to the speed difference becomes large (fuel efficiency is bad). The inside is rather a load (the propulsion efficiency is better for one axis than for the two shafts) Reduce the propulsive force.
■Water wheels row
【Wheel & water stable plate】
Energy efficient (fuel economy) is good because it arranges the submersible watercock in full breadth and pushes a large amount of water backward. Propulsion efficiency improves as the amount of water pushed backward increases. When arranging the aqueduct into full one, the area to be scooped widens, the amount of water pushed backward increases, the propulsion efficiency improves (fuel efficiency is good).
The screw propeller adopted by many of the existing ships can not be larger than the constraint of the floor diameter due to the depth of the waterline and the restriction of the upper end of the propeller under the water surface (if the propeller is 100 m in radius and efficiency is It gets much better). There is a constraint on the amount of water pushed backward, and efficiency can not be improved beyond current efficiency (fuel efficiency is bad).
When the propulsion device is a steering device
【Bottom view】
■Comparison table of steering devices
| Types of ship form | Steering device | Number | Structure of steering |
| Normal ship (mono hull) | rudder | １ | Change the flow of water with a rudder |
| Hydrofoil | water jet | ２or４ | Rotate the jet port to control the direction |
| Catamaran | water jet | ２or４ | Rotate the jet port to control the direction |
| through hull ship (kurokiship) | A submerged water wheel | ５－９ | Rotate the water wheels individually and control direction |
■Steering system
KurokiShip is a propulsion device steering device. Rotate the multiple turbines individually to change the direction of the ship. Reverse the water wheels and go backwards. The water wheel is driven to rotate by a directly connected electric motor. Electric motors are good at rotation fluctuation. Rapid stop and reverse can be done immediately from full rotation.