Below we can see a set of propellers ready to be fitted on a new electric ship built by our good customer Holland Shipyards Group, a well-known shipyard from The Netherlands where many highly efficient and comfortable hybrid and pure electric ferries were built.
But…. why is so important CFD hydrodynamics and propeller design for battery powered ships?
Let´s see below the five reasons:
- POWER DEMAND: energy is almost everything nowadays on shipping. Efficient CFD design of propeller (and hull) implies obviously less power, less motor and drive train, less cabling, less energy cost every time you recharge your batteries, less time charging in port and less….
- WEIGHT & SPACE: Batteries are very heavy and bulky, don’t waste your ship’s deadweight and cargo capacity by carrying heavy batteries up and down. Traditional liquid fueled ships with combustion engines can afford to move around extra-fuel capacity on its tanks as that implies a little effort, that is no longer the case with battery propelled ships. But don’t forget about….
- COST: batteries are very, very expensive, don’t waste your newbuilding budget on extra batteries, optimize your hull and propeller and your pocket will be happy with every kWh saved. Every 1% improvement on resistance and propeller efficiency is automatically translated into the investment and operational cost of the ship to a much larger extent than on a conventional vessel.
- E-MOTOR MATCH: Modern e-motors driven by frequency converter offers different torque limit curves compared to diesel engines; this needs a customized design to take advantage of it. Linking a CFD design of propeller and hull results on a perfect match to take advantage of a modern e-motor response.
- NOISE: When you sail on a pure electric ship with no combustion engines running, you like to enjoy the silence on the water , of course you don’t want to hear noise and feel shakes and vibrations of a cavitating propeller in the stern, that is the reason why you need to pay extra attention to the design of the propeller and hull by doing a complete CFD analysis and optimization in self-propulsion condition.