As the world’s only manufacturer of rotary engines, Mazda continues to develop and explore the flexibility of this unique rotary engine; this includes a new development of the Rotary Hydrogen engine programme announced at the 2003 Tokyo Motor Show.
The hydrogen-powered version of the RENESIS presents a realistic example of a hydrogen-gasoline dual-fuel system maintaining a traditional driving feel, yet producing extremely clean emissions through the use of hydrogen. Fun to drive and environmentally sound, the RENESIS Hydrogen Rotary Engine assures the same ease-of-operation and reliability whether the engine is running on gasoline or hydrogen fuel.
Unlike other alternative fuels, which are reliant on fossil fuels for their production, hydrogen is a naturally occurring gas which when burnt produces water as an exhaust product, making it the most environmentally friendly fuel available.
However, due to the volatile nature of the gas, the more common Otto cycle (reciprocating) engine needs substantial and expensive development to run on hydrogen to avoid pre-ignition on the intake cycle.
The rotary engine, due to its unique nature, can run on hydrogen with very little modification. It has the injection, compression, ignition and exhaust areas separated from each other so no pre-ignition of the gas occurs.
An electronically-controlled hydrogen injector system draws air from the side port during the induction cycle and uses dual hydrogen injectors in each of the engine’s twin rotor housings to directly inject hydrogen into the intake chambers.
In addition, since the engine requires few modifications to run on hydrogen, it could enable production of a relatively low-cost hydrogen-powered alternative-fuel vehicle. The engine has been developed with a dual-fuel system, allowing it to run on either gasoline or hydrogen, offering flexibility to promote the usage of hydrogen fuel and the development of a supporting infrastructure.
As a volatile fuel with considerable potential energy, hydrogen produces similar power to fossil fuels with little difference in power output from the rotary when compared to the engine run on petrol.
Mazda is still several years off producing a hydrogen car for customer use but is one of the few manufacturers pursuing alternative fuel sources that do not rely on fossil fuels.
Mazda continues to develop the idle-stop system, regenerative braking systems and other means of improving the efficiency of the entire vehicle. By combining these various technologies, Mazda is aiming to achieve advanced clean-running vehicles that also deliver an exceptional driving experience.Published 22 October 2003