{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f63bd2a14cda1716d057e2782bc7d5da57d248b9472e786ed8dd8f81eb0740f3","created":"2026-10-03T07:18:04Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"311c613f101e3358ce1dc440166e5b41d30caa6220c6ffb798125a5a3075d39c","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"fluid.turbulent-combustion.bending-effect","kind":"phenomenon","literature_status":"contested","n":"1","parents":[],"plain":"Stirring a premixed flame harder makes it burn faster, but at strong stirring the gain levels off or even reverses. Is this caused by stretching of the flame surface, local blow-out of the flame, unequal diffusion of fuel and heat, or by how burning speed is defined in each experiment?","posed_since":"","precise":"For premixed flames the turbulent burning velocity $S_T/S_L$ grows nearly linearly with $u'/S_L$ at low intensity and then bends to slower growth at $u'/S_L$ from a few to several tens depending on geometry and mixture; whether the onset is set by the Karlovitz number Ka (flame time over smallest-eddy time) is part of the question. Identify the mechanism (saturation of flame-surface production by stretch, local extinction, Lewis-number Le and differential-diffusion effects, geometry-dependent definitions of $S_T$, finite residence time) and give a predictive $S_T(u'/S_L, L/\\delta_L, \\mathrm{Le}, \\mathrm{Ka})$. An answer is a closed theory confirmed by direct numerical simulation and by Bunsen, spherical and stagnation-flame experiments.","problem_ref":null,"references":"","settled_by":"Direct numerical simulations with detailed chemistry across Ka and Le, analysed with a common $S_T$ definition and matched to experiments in at least two flame geometries.","status_note":"","title":"Origin of the bending of turbulent burning velocity at high intensity","topic_ref":"ff8822779d7d3829d62f794eaee78060074a7c7c5588960c0eae974a587339ac"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"dab22f887ebd73d04106547f408140df056b56caae487765093b6af295511808","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3d573a14c2deb387750a1b0a4e10bededc1da11bb578a11ad47438f199a84181","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Dqk7RBLk4HEZ_0uL1cheyxLlsIILFsjpd---7lSW0oRxFPd3cfoPm8d3qyQwfJGCcXnrw-cRv6RvWcLRmSH8Aw"},"schema":"pubphys.envelope/1"},"record_hash":"dab22f887ebd73d04106547f408140df056b56caae487765093b6af295511808","leaf_index":1445}