DieselShip

Resistance and propulsion
 Resistance and propulsion concepts
 
 Interaction between ship and propeller
 
Any propulsion system interacts with the ship hull. The flow field is changed by the (usually upstream located) hull. The propulsion system changes, in turn, the flow field at the ship hull. However, traditionally naval architects have considered propeller and ship separately and introduced special efficiencies and factors to account for the effects...

 
Propellers
Introduction | Propeller curves | Analysis of propeller flows| Momentum Theory | Lifting surface method |
Boundary Element Methods | Field Methods |
Lifting-surface methods
 
The discussion to substitute the lifting-line approach by lifting-surface theories dates back to the 1950s, but the realization of this goal was initially impossible for real ship propeller geometries due to insufficient computing power. The earliest lifting-surface attempts were...

Propellers
Introduction | Propeller curves | Analysis of propeller flows| Momentum Theory | Lifting surface method |
Boundary Element Methods | Field Methods |
Field methods
The common procedure to run unsteady propeller vortex-lattice or panel methods contains an inherent weakness. The ship is usually represented by the velocity field measured without the propeller at the propeller plane, i.e. the nominal wake. But in a real ship, the propeller rearranges the streamlines that...

Propellers
Introduction | Propeller curves | Analysis of propeller flows| Momentum Theory | Lifting surface method |
Boundary Element Methods | Field Methods |
Momentum theory
Momentum theory models the propeller as a simple actuator disk accelerating  she flow in the axial direction by somehow creating a pressure jump in the  propeller plane. The propeller is then seen as a continuous circular disk with infinite blades and AE/A0= 1. The model is too crude to be of any...

Propellers
Introduction | Propeller curves | Analysis of propeller flows| Momentum Theory | Lifting surface method |
Boundary Element Methods | Field Methods |
Boundary element methods
 
Panel methods were developed to overcome the disadvantage of an incomplete geometry model. Panel methods also model the blade thickness and include the hub in the numerical model. The development of panel methods for propellers was apparently not an easy task. After the ship hull flow could be...