Installation
In the veiw of turning center, how to calculate the thrust
For example, assuming that a thruster with 100 kg of thrust is installed,
A : 100kg thrust x 11m leverage = 1100kgm torque to rotate the boat
B : 100kg thrust x 10m leverage = 1000kgm torque to rotate the boat
The boat in position A, you will get 10% more thruster to turn the boat around.
Therefore, the thrust force of the thruster varies depending on the installation position.
Recommended instatalltion depth
2 ways to determine an installation depth.
1.We recommend the thruster depth(WD) lower than tunnel inner diameter 1/2 from the waterline in general.
2.It is recommended to install in the 3/4 or4/4 depth of tunnel diameter if the conditions of ship allow.
3.When the Hull is low, the end of the tunnel should be installed inclined as follows.
Tunnel length
1) The optimal propulsion needs 2 to 4 times length of the tunnel inner diameter.
But it should not exceed 6 times. It more than 6 times, the propulsion will be reduced.
2) If the tunnel is too long, it increases friction resistance and reduce the propulsion.
On the other hand, if the tunnel is too short, it creates cavitation, reduce the propulsion and make noise and vibration.
Tunnel ends
1. Rounded tunnel ends will maximize thrust and minimize noise.
2. We recommend to round the tunnel connection to the hull-side as much as possible.
The optimal rounding has a radius of 10% of the tunnels diameter
3. In case of hardship in rounding like steel, aluminum vessel, the champer is required
Installation to reduce resistance
It is recommended to modify the shape as shown in the following figures 2 and 3 in order to reduce the decrease in ship speed due to the impact of the water current on the tunnel when sailing.
Installation of thruster(Single propeller)
The best position of thruster propeller is the center of hull. But if not, you can refer to below
