In the Zero Emission Lab we look into cavitation and propulsion. These two are closely connected: to drive a propeller we need a power source, and if we look into propulsion, we need a propeller.
MARIN investigates propellers and how these propellers are driven. We want to know how much power a propeller can supply, whether a propeller will make noise under water, and if cavitation will occur. All this research is done in our Cavitation tunnel.
Of course a propeller must be driven by a power source. Today a diesel engine is used, but in the future we want to change to a cleaner power source in order to achieve zero emission. Are we going to build hybrid ships,or ships that sail on hydrogen or a battery, like cars? And how do we do this? All this research is done in the Hydro-systems integration lab which can be seen as the engine room of the future.
As a ship’s propeller rotates in water, bubbles filled with water vapour form on front side of the propeller blades. This is referred to as cavitation. These bubbles disappear again but they do not explode, rather they implode. Continuous implosion causes pressure waves that cause vibration in the stern and inboard noise hindrance. Cavitation can also damage the propeller blades.
Propeller replacement is costly and thus wear and tear of the propeller blades has to be prevented as much as possible. Heavy vibration and loud noise is disruptive to passengers and crew. In addition, vibration can cause damage to a vessel’s structure, systems and cargo.
Thus, cavitation investigations are essential, and preferably in the design phase. Because correcting faults after the ship has been built is often not possible or extremely expensive. With good hydrodynamic design, we endeavour to reduce cavitation as much as possible.
Engine room of the future
The Hydro-systems integration lab resembles an engine room of a ship. The engine room contains a combustion engine and an electromotor to drive the ships propeller. The electromotor can be fed through a battery, fuel cell, generator or a combination of all systems.
A Fuel Cell produces electricity from hydrogen. Hydrogen is made by separating water into hydrogen and oxygen. The electricity is used to drive the propeller through the electromotor.
In the engine room of the future we can research all kind of things like ‘How to design a good engine room? If something goes wrong, will it be possible to continue the journey of the ship? How do we control such an engineroom?’ In the future we want to sail zero emissions; this lab will help us to explore how.
Wist je dat
cavitation is measured and observed with high-speed cameras that take a million pictures per second?