The latest industry trends show an emerging competitiveness for eco-friendly products, and there is no exception for shipbuilding industry. The ship building industry seeks to develop eco-friendly vessels as part of an effort to preemptively cope with toughening environmental regulations. The development of technologies are in three major fields hence these data have led to the conclusion that the PBCF, simple in structure, can be an excellent energy-saving device.
The results obtained also showed the PBCF thoroughly extinguishes hub vortex cavitations but hardly influences the cavitations generated on propeller blades or tip vortex cavitations. These results lead us to believe that PBCF is also effective in the reduction of propeller noise. From the computational results, both the force predictions and the detail flow visualizations show that a correctly designed PBCF is an effective energy-saving device. design, engine systems and gas emission processing. The key of this research is to cut harmful substances in emissions and reduce fossil fuel consumption, while maintaining ship speed.
PBCF is the originated device to be focused in the recovery of energy from the flow out energy in propeller hub vortex. Its fundamental mechanism and effects have been repeatedly verified through numerous series of model tank tests and actual ship measurements from the first stage of the development. Under the current importance of the global environmental problems, the demand for the PBCF has been continually growing up from not only as an energy saving device but also as an environment-friendly product.
The design of a propeller energy-saving device, PBCF, by computational fluid dynamic is presented in this research. The key design points of PBCF are first pointed out, and the effectiveness of different geometry settings are investigated from computations results acquired from commercial software ANSYS CFX.
A screw propeller generates free vortices called tip vortices and, in its slipstream, a hub vortex. This paper proposes the use of a Propeller Boss Cap Fin (PBCF) to diffuse and weaken the hub vortex by changing the flow near the boss cap, thereby enhancing propeller efficiency. Research and development work on the PBCF was carried out through flow visualization.
The designed PBCF tends to enhance propeller efficiency, decreases induced resistance due to hub vortexes by diffusing and reducing the vortexes generated by the boss cap top, according to the same number of fins as that of propellers attached to the boss cap in the rear of the propeller. The pitch angle and the installed angle of fins are the most important design points of PBCF. Results showed gains of 5.35% in propeller efficiency