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Title: What makes detonation cells regular in some mixtures and irregular in others?
Plain: Detonations in mixtures diluted with argon leave neat, regular cells, while in fuel-air mixtures the pattern is chaotic and pockets of unburned gas appear behind the front. What decides this, and does the irregularity change how the detonation survives?
Precise: Cell regularity correlates with the stability parameter $\chi = (E_{a}/(R T_{s})) (\Delta_{I}/\Delta_{R})$, the reduced activation energy times the ratio of induction length to reaction length. Determine whether $\chi$ or another parameter quantitatively predicts the width of the cell-size distribution, whether irregular detonations burn unreacted pockets by turbulent mixing, and whether this explains the critical tube diameter $d_{c} \sim 13\lambda$ for irregular mixtures and its larger multiples for regular ones. An answer is a quantitative classification criterion with its mechanism.
Settled by: A systematic set of experiments and resolved simulations over $\chi$ measuring cell statistics, unburned-pocket consumption and critical diameters, fitted by one criterion.
Kind: phenomenon
Answer type: classification
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)