{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"1fed705b9f0577cf4a41f91ec91374af5275b136f1d999636174a69a78dadaff","created":"2026-10-03T07:18:04Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"bf16cc5045886610c2377bb29f8f2b21bd680190119f356ecde9af67d0adae27","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"fluid.rb-convection.rotating-diffusion-free","kind":"well-posed","literature_status":"partially-resolved","n":"1","parents":[],"plain":"In a fluid layer heated from below and spun fast, as in planetary cores and oceans, theory predicts a heat-transport law that does not depend on viscosity or heat diffusion. Simulations now show this law, but whether laboratory flows reach it and how it depends on the fluid are open.","posed_since":"","precise":"Rotating Rayleigh-Benard convection with Ekman number $\\mathrm{Ek}=\\nu/(2\\Omega H^{2})\\to 0$ and supercriticality $\\mathrm{Ra}\\sim=\\mathrm{Ra}\\,\\mathrm{Ek}^{4/3} >> 1$ ($\\Omega\\ \\text{rotation rate},\\ H\\ \\text{layer height}$). The diffusion-free (geostrophic turbulence) prediction is Nu - 1 ~ $\\mathrm{Ra}\\sim$^(3/2) at fixed Pr. Determine whether this law holds in laboratory cells with sidewalls and centrifugal effects, its Prandtl-number dependence for Pr from about 0.03 to 7, and the Ra~ at which it crosses over to non-rotating convection.","problem_ref":null,"references":"","settled_by":"Heat-transport measurements in rotating cells at $\\mathrm{Ek} <\\sim 10^{-8}$ and $\\mathrm{Ra}\\sim$ well above onset at several Pr, compared with DNS of the same geometry.","status_note":"DNS with no-slip plates and periodic sides at $\\mathrm{Pr} = 1$, $\\mathrm{Ra}\\ \\text{up to}\\ 3 x 10^{13}$ and $\\mathrm{Ek}\\ \\text{down to}\\ 5 x 10^{-9}$ show $\\mathrm{Nu} - 1 \\sim \\mathrm{Ra}\\sim^{(3/2)}$, with a steeper $\\mathrm{Ra}\\sim^{3}$ regime at lower $\\mathrm{Ra}\\sim$ (Song, Shishkina, Zhu, J. Fluid Mech. 2024); laboratory confirmation and the Pr dependence remain open.","title":"Laboratory confirmation of diffusion-free heat transport in rapidly rotating convection","topic_ref":"6d62b34c8e014f88ffcbe79c7a106852a6fbdddb7610842d4118538cb9b5370d"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"b2292dbe3244c287ec5abe5fd149a14f362eb858fce346d7ba03da093aec309b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"6001aec788702f36d093065c5da50703d0dbf5348e6c347e217f9c6c09184d78","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"6vVSEtAkHBDzDUtId7QJPFRjVaXx-MEdV0MR1TjKor0tj282uJ15Ha77bQ5azV2dMAqrt_Tv2HqBB0dbajP8Dg"},"schema":"pubphys.envelope/1"},"record_hash":"b2292dbe3244c287ec5abe5fd149a14f362eb858fce346d7ba03da093aec309b","leaf_index":1426}