Parametric Sensitivity and Ignition Phenomena In Hydrogen Oxygen Mixtures

The occurrence of ignition phenomena in hydrogen-oxygen mixtures has been described in terms of parametric sensitivity. The generalized criterion for parametric sensitivity has been used to quantitatively define the critical conditions corresponding to the system ignition. Accordingly, criticality is defined as the situation where the normalized objective sensitivity of the maximum of either the temperature or the concentration of hydrogen radicals, with respect to the initial temperature or the initial pressure, exhibits a maximum. The criterion predicts the explosion peninsula characteristic of the hydrogen-oxygen mixture in good agreement with experimental findings. In the region of low initial pressure values, next to the first explosion limit, a boundary where a sharp transition from weak to strong explosion occurs has been identified. The related phenomena have been discussed through detailed simulations.