Role of temperature-gradient steepness on development of hydrogen-oxygen detonation with ozone sensitization

Abstract

This work carries out one-dimensional simulations on spontaneous initiation and development of detonations from hot spots with initial temperature gradients embedded with non-autoignitive H2O2 mixtures. Role of temperature-gradient steepness on the development of detonations inside and outside hot spots and the relationship of it to ozone sensitization are examined by changing gradient slope and O3 addition. It is found that steepening temperature gradient has negative effect on initiations and a critical gradient is identified for different O3 additions, below which spontaneous initiation fails. However, the sustenance of a developing detonation is not only related to the steepness, but also to the reactivity of mixtures with O3 additions. High O3 additions permit a detonation to be more likely to sustain outside hot spots; while for low O3 additions, the sustenance depends nonmonotonically on the slope, which cannot be predicted by the idealized reactive flow system with a constant specific heat ratio and the reduced reaction model. The results clarify the suggestions of He & Clavin [1] that temperature gradient may prevent sustenance of a developing detonation and the transmission of detonation to the uniform fresh mixture.