Cloudia is a prototype catamaran designed to test the tall red and white towers, called Flettner rotors, which were first describe 80 years ago The outboard motor is used as an auxiliary, to move the boat into position for the tests. A small electric motor spins the rotors. The spinning rotors then develop lift similar to the lift produced by a spinning curve ball thrown by a baseball pitcher. The lift produced provides the boat's propulsion through the water. The rotors need to spin at approximately 3 – 5 times the wind's speed. A beam reach is the best point of sail for this rig. Cloudia successfully completed her sea trial last month.
Cloudia's two Flettner rotors are built of carbon fiber and foam. The taller tower is approximately 18 feet and 300 pounds, the shorter is approximately 14 feet and 275 pounds. The pattern of interrupted red stripes was used to help film the towers' speed of rotation, which can be 180 RPM in 5 knots of wind.. The black scores on the horizontal base of the rotors were used to accurately measure the rpm of the rotor using a stroboscopic device. The metal fences in the cockpit were built to give the appearance safety for the film. Unfortunately the movie's narrator chose to stand next to the spinning rotors with the safety grids behind him.
Cloudia was built to only test the use of Flettner rotors, but her name refers to the environmental goals of a much larger project to combat global warming developed by Steven Salter, a professor and researcher at Edinburgh University. The goal is to have enormous, unmanned sail boats propelled by Flettner rotors in the oceans, generating clouds to cool the earth. Turbines dragged behind the boats and solar panels will produce the electricity needed to aerosolize sea water, perhaps using ultrasonic humidifiers. The cloud making technology for this project is being developed at other research sites. The next step in the project is to build a 60 foot catamaran with the capability to easily disable Flettner Rotors, perhaps using towers that can be inflated and deflated.
This research project is supported by the Discovery Channel and will be featured in their series on Global warming. Cloudia's sea trial was filmed by Impossible Pictures. We wrote this explanation based of a conversation with Captain Bill who was responsible for Cloudia's electrical engineering and captained her sea trial.