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You are here: Marine Templates and Tutorials > Marine Hull Template > Modelling Marine Vessel > Propeller Performance
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Propeller Performance
The propeller generates a thrust that moves the ship/ vessel forward overcoming the resistance offered by the fluid. The simulations are performed for self-propelled conditions, where the propelling of the vessel is caused only by the propeller. There are no additional forces or moments on the vessel, such as those caused by a towing bar or hawser.
In the Steady-state, force balance in self-propulsion requires that,
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8.13 |
where
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Offered Resistance |
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Thrust required to overcome the resistance |
Advance ratio
The advance ratio of a propeller is defined as:
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8.14 |
when it is exposed to a water speed, 
. 
and 
are the speed and the diameter of the propeller respectively.
KT, KQ curves
A propeller can be characterized by two non-dimensional parameters which are both functions of the advance coefficient 
. They are 
- thrust coefficient and 
-torque coefficient, given by the following expressions:
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8.15 |
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8.16 |
Typically, the performance of a propeller is illustrated through curves of 
and 
against 
, as shown below:
Figure 8.16 - Performance curves1Source: mit.edu, Maneuvering and Control of Surface and Underwater Vehicles