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Title: Microwave-based laboratory experiments for internally-heated mantle convection

The thermal evolution of terrestrial planets is mainly controlled by the amount of radioactive heat sources in their mantle, and by the geometry and efficiency of solid state thermo-chemical convection within. So far, these systems have been studied using numerical methods only and cross validation by laboratory analogous experiments has not been conducted yet. To fill this gap we perform the first laboratory experiments of mantle convection driven by microwave-generated internal heating. We use a 30×30×5 cm{sup 3} experimental tank filled with 0.5 % Natrosol in water mixture (viscosity 0.6 Pa.s at 20°C). The fluid is heated from within by a microwave device that delivers a uniform volumetric heating from 10 to 70 kW/m{sup 3}; the upper boundary of the fluid is kept at constant temperature, whereas the lower boundary is adiabatic. The velocity field is determined with particle image velocimetry and the temperature field is measured using thermochromic liquid crystals which enable us to charaterize the geometry of the convective regime as well as its bulk thermal evolution. Numerical simulations, conducted using Stag-3D in 3D cartesian geometry, reproduce the experimental setup (i.e., boundary conditions, box aspect ratio, temperature dependence of physical parameters, internal heating rate). The successful comparison betweenmore » the experimental and numerical results validates our approach of modelling internal heating using microwaves.« less
Authors:
; ; ; ; ;  [1] ; ; ;  [2]
  1. Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris-Diderot, CNRS, 1 rue Jussieu, F-75005 Paris (France)
  2. National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)
Publication Date:
OSTI Identifier:
22257174
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1565; Journal Issue: 1; Conference: PIM 2013: International conference on processes in isotopes and molecules, Cluj Napoca (Romania), 25-27 Sep 2013; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPUTERIZED SIMULATION; CONVECTION; EFFICIENCY; HEAT SOURCES; HEATING RATE; LIQUID CRYSTALS; MICROWAVE RADIATION; MIXTURES; PARTICLES; SOLIDS; TEMPERATURE DEPENDENCE; VISCOSITY