Variability of complex oscillatory regimes in the stochastic model of cold-flame combustion of a hydrocarbon mixture

Processes of the cold-flame combustion of a mixture of two hydrocarbons are studied on the base of a three-dimensional nonlinear dynamical model. Bifurcation analysis of the deterministic model reveals mono- and bistability parameter zones with equilibrium and oscillatory attractors. For this model, effects of random disturbances in the bistability parameter zone are studied. We show that random forcing causes transitions between coexisting stable equilibria and limit cycles with the formation of complex stochastic mixed-mode oscillations. Properties of these oscillatory regimes are studied by means of statistics of interspike intervals. A phenomenon of anti-coherence resonance is discussed. This article is part of the theme issue ‘Transport phenomena in complex systems (part 2)’.

Examination of the influence of multi-injection strategy on thermodynamic indexes of engine cycle and on the emission of toxic compounds

The main target of this work was to investigate on the 1-cyl. research engine concerning practical realization possibilities of cold-flame-combustion when operating with high and very high Exhaust Gas Recirculation (EGR) rates. After determining of possibilities of lowering NOx and Soot emissions for EGR rates ca. 40-60% some further investigation on optimization of SOI and CoC parameters were performed. Additionally, some preliminary investigations of the optimization of combustion parameters when applying various strategies of multi-injection have been conducted and analyzed.

A gas chromatographic detector based on the quenching of luminescence from a P4/O2 cold flame

Gas chromatographic effluents were detected by their quenching effect on the luminescence of a steady 'cold flame', as provided by the gas-phase reaction of phosphorus vapor and oxygen. The response of organic compounds correlated with their 'ease of oxidation' in accordance with the literature, suggesting that such compounds act as oxygen atom scavengers in the branched-chain P4/O2 reaction.Most substances showed linear response over one to two orders of magnitude, and minimum detectable amounts ranged from 2 × 10−9g (benzaldehyde) to 2 × 10−4g (dichloromethane). The detector temperature could be varied to (a) alter response ratios, i.e. selectivity, among some types of compounds; and (b) produce easily-obtained Arrhenius plots. However, the response (luminescence quenching) of most compounds was independent of temperature over a considerable range.