How do these differences effect the design criteria for a hydrogen fuel internal combustion engine?
• The high specific energy by weight of hydrogen gas is an advantage which should be extended to the utmost in a hydrogen powered vehicle. This suggests that every effort should be made to minimize mass and bulk throughout the vehicle with every structural feature be designed to enhance light weight and where practical to carry fuel. • While hydrogen has a high specific energy by weight it is a bulky fuel by volume. It is this characteristic which creates the technological barrier to utilizing hydrogen in transportation. Hydrogen gas displaces the incoming charge of air in a naturally aspirated engine reducing the volume of air tapped in the combustion chamber. This can be overcome by direct injecting hydrogen into the combustion chamber at the end of the air induction phase. It is known that a direct to chamber fuel delivery is essential for good BSFC in a two/stroke engine and so a DI system would achieve both objectives of fuel economy and high output in a two-stroke hydrogen engine
