{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"206cc366f06a5819b2a8086a46011e82df06a1dd4d88e8a90b8eccf97b4a8555","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ad5938a0aee96c1c52b1e3ab566b6d801fbef9a2b31785693cd7b83167cbddb8","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"abbc1b38e3e73763c518e8e730f4a45cde5665745c668108da76c3727eeaf000","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"fluid.turbulent-combustion.cell-size-prediction","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"The front of a gas detonation is a pattern of crossing shock waves that scratches a fish-scale pattern on a sooted wall, and the width of these cells decides whether a detonation can pass through a pipe or an opening. At present the width can only be estimated from chemistry to within a factor of a few.","posed_since":"","precise":"For gaseous detonations ($\\mathrm{H_2}$-$\\mathrm{O_2}$-Ar, $\\mathrm{H_2}$-air, hydrocarbon-air) at initial pressure $p_0$ and temperature $T_0$, predict the mean cell width $\\lambda$ from the detailed chemical mechanism. Empirical correlations $\\lambda = A \\Delta_I$, with $\\Delta_I$ the induction length of the one-dimensional steady detonation, need $A$ between about 10 and 50 depending on mixture. An answer predicts $\\lambda$ within 20 percent across mixtures and initial conditions with no fitted $A$.","problem_ref":"ad5938a0aee96c1c52b1e3ab566b6d801fbef9a2b31785693cd7b83167cbddb8","references":"","settled_by":"Three-dimensional resolved simulations with validated chemistry, or a reduced theory, that reproduce measured cell widths for several mixtures and pressures without mixture-specific tuning.","status_note":"","title":"First-principles prediction of detonation cell size from mixture chemistry","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"fd89163619c4521f160ad136f06466cbc0a2c742d294d432c4a9c0fa2b608d8b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3d7a0a03ace8d4bbca3f6f61b21301f3df0daef619555a2cf895d852d725e8ce","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"XN5nPqB2qMzq679VhvAH23b--U4nhR1keJ419cF_-0b-0aGp168PlKGvaE51kY_Pws4z5CRzvww6ZTqsoZw0Aw"},"schema":"pubphys.envelope/1"},"record_hash":"fd89163619c4521f160ad136f06466cbc0a2c742d294d432c4a9c0fa2b608d8b","leaf_index":3284}