Development of Energy-Saving Devices for a 20,000DWT River–Sea Bulk Carrier

A reduction of fuel consumption and an increase in efficiency are currently required for river–sea bulk carriers. Pre-swirl and ducted stators are widely used devices in the industry and efficiency gains can be obtained for single-screw and twin-screw vessels. Based on the hydrodynamic characteristics of the 20,000DWT river–sea bulk carrier, in this study, we proposed, designed, and tested a series of pre-swirl energy-saving devices (ESDs). The experimental results demonstrate that the proposed ESDs improved the propulsive efficiency and reduced the delivered power. The results confirm the success of our ESD for the 20,000DWT river–sea bulk carrier. We validated the role of Reynolds-averaged Navier–Stokes (RANS) computational fluid dynamics (CFD) in the twin-skeg river–sea vessel ESD design and found the circumferential arrangement and number of stators to be important factors in the design process.