Influence of geometrical configuration on spontaneous hydrogen ignition process

Hydrogen is considered as a future fuel which may replace traditional ones. There are several arguments for utilization of the hydrogen : high heat of combustion, zero CO ₂ emission, etc. But there are also significant disadvantages : low density, high cost of production and safety problems. Nowadays, hydrogen, used in vehicles, can be stored at pressure up to 70 MPa, but high pressure discharge of the hydrogen into atmosphere can cause spontaneous ignition, so a failure of any element of high pressure hydrogen installation generates hazard of potential fire and explosion. The experimental research conducted in the Combustion Laboratory, Institute of Heat Engineering, Warsaw University of Technology gave new data concerning influence of the geometry of the extension tube on the hydrogen ignition process. In the experimental investigation it was confirmed, that the process of hydrogen ignition is stochastic in nature, since it depends upon many parameters. One, which is very difficult to control, is the process concerned with bursting of the diaphragm that closes high pressure hydrogen container. In the paper, a comparison is presented of the experimental results obtained in the Combustion Laboratory of Warsaw University of Technology with numerical simulations conducted at the Dept of Aerospace, University of Michigan.