SPINNING BLOCK OF LEVITATING ICE MAKES POWER
FUTURE missions to Mars may well be powered by carbon dioxide-fuelled engines, thanks to a recent prototype developed by Northumbria and Edinburgh universities.
Exploiting a phenomenon known as the Leidenfrost effect, researchers hope that their engine could be powered by the vast amount of dry-ice deposits found on the red planet, thereby reducing the need to transport fuel on interplanetary missions.
The new type of engine proposed by the researchers takes advantage of the Leidenfrost effect, which is commonly observed when beads of water dropped onto the face of a hot frying pan appear to canter across its surface. The phenomenon is exaggerated when the surface is composed of ridges, where the droplet effectively propels itself across the top of those ridges.
To create a prototype engine using this effect, the research teams were able to levitate a circular block of dry ice above a heated aluminium surface, where it floated on a pillow of evaporated gas vapour over a circular pattern of ridges, in effect creating a turbine. This meant that when the dry ice was subject to the Leidenfrost effect, instead of simply rolling across and off the surface, it rotated in a circle. With a series of magnets and copper coils attached, the block of ice acts as an electric motor to create an alternating current. This is the first time that the Leidenfrost effect has been used to produce any useful form of energy, explained Dr Gary Wells, a research fellow in the department: Physics and Electrical Engineering at Northumbria University. On Mars, the aluminium plate will be heated using waste heat and exploit the low boiling point of frozen carbon dioxide. — Gizmag.com.