چکیده
|
Surface piercing propellers are widely employed in high-speed crafts due to having
many favorable features. These propellers operate at both submerged and semisubmerged states. In submerged state, to enhance the propeller hydrodynamic
performance, the blades are usually manipulated through artificial ventilation by
adding the air duct which is located at the propeller suction side. In current study, a
5-blade propeller proficiency has been studied under different operational conditions
of 16 m catamaran vessel experimentally, the sea trial, and numerically using
Computational Fluid Dynamics (CFD). The propeller behavior has been investigated
under four sea trials while the propeller torque has been sampled at different engine
states and vessel speed. The numerical study through CFD has been done to analyze
the propeller behavior under different conditions, submerged and semi-submerged
states. The numerical results have been validated by experimental observations. The
propeller proficiency has been studied in two vessel motion stages which are preplaning and post-planing. The results depict that the maximum torque is observed in
submerged state at the last step of pre-planing mode while the engine speed is 2300
rpm. The propeller torque is reduced 10 to 16% at 2500 rpm in post-planning stage.
In submerged state, the propeller proficiency is negligible at pre-planing mode.
|