| The_air_car_2 Tata Motors,
India largest automotive company, on Feb. 5, 2007 announced that it has
signed an agreement with Moteur Development International
(MDI) of France, inventors of the car, to develop a car that runs on compressed air, thus making it very economical to run and be almost totally pollution free. This article in Rediff India Abroad and the MDI website gives further details. The air engine has 4 two-stage pistons, i.e. 8 compression and/or expansion chambers on one crankshaft. The pistons work in two stages: one motor stage and one intermediate stage of compression/expansion. They have two functions: to compress ambient air and refill the storage tanks; and to make successive expansions (reheating air with ambient thermal energy) thereby approaching isothermic expansion. It has injection similar to normal engines, but uses a special crankshaft and pistons, which remain at top dead center for about 70 degrees of the crankshaft's cycle; this allows more power to be developed in the engine. The engine is powered by compressed air, stored in a carbon-fiber tank containing 90 cubic meters (3178 cubic feet) of air at 30 MPa (4500 psi). The expansion of this air pushes the pistons and creates movement. The atmospheric temperature is used to re-heat the engine and increase the range. The cars have the following characteristics: * Are light
weight vehicle that can reach speeds up to 220 kmph. ( 5/8 times 220 is
137 MPH )
Mdi_air_engine The car will be produced in both a single engine compressed air cars, the MiniCAT and CityCAT and a dual engine hybrid, a compressed air engine plus a multi-fuel internal combustion engine. The hybrid has been conceived as much for the city as the open road and will be available in all MDI vehicles. The engines will work exclusively with compressed air while it is running under 50 km/h in urban areas. But when the car is running at speeds over 50 km/h, the engines will switch to fuel mode. The engine will be able to use gasoline, biodiesel, natural gas, LNG, alcohol, etc. It was not clear whether the air engine would also be used as an ICE or whether two engines would be employed in the hybrid. Engines will be available with 2, 4 and 6 cylinders. When the air tanks are empty the driver will be able to switch to fuel mode. The car -- MiniCAT -- could cost around US$8,000 (Rs 350,000) in India and would have a range of around 180 miles (300 km) between refuels. The cost of a refill would be about US$2.00 (Rs 90). |
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