Theoretical study of gas heated in a porous material subjected to a concentrated solar radiation
G. Olalde, J.L. Peube, M. Daguenet
1980
Revue de Physique Appliquée
2014 Les auteurs calculent analytiquement et numériquement la distribution des températures dans le solide (matériau poreux) et le fluide (gaz) en fonction des paramètres du système. Un réacteur expérimental a été conçu et installé au four solaire de 6,5 kW du Laboratoire d'Energétique Solaire à Odeillo (France). Différentes experiences ont été réalisées et ont permis de tester la validité du modèle théorique. Abstract. 2014 The authors calculate analytically and numerically temperature
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... tion in the solid (porous material) and the fluid (gas) from a system of adimensional equations composed of one differential equation of order 4 and another one of order 2 with constant coefficient. An experimental reactor was constructed for the verification of the model; it was designed to be used with 6.5 kW solar furnace of Solar Energy Laboratory in Odeillo (France). Revue Phys. Appl. 15 (1980) 423-426 MARS 1980, Classification Physics A hstracts 47.25Q Nomenclature A = surface area for theoretical transfers per unit volumen of porous material (1ç)/1:; A i, A j, aj, Bl, b 1 = constants ; Cpgas specific heat ; Dpparticle diameter ; h = heat transfer coefficient ; L = porous material length ; L+dimensionless porous material length L + = L/Dp ; Mi, Mj, mj = constants ; Nu = Nusselt dimensionless group ; Pr -Prandtl dimensionless group ; Re = Reynolds dimensionless group based on packing size, Dp ; T = solid température ; T+ = solid dimensionless temperature ; Xcoordinate, axial distance through the porous material ; X+ = dimensionless axial distance through the porous material X + = X/Dp ; v = fluid average velocity in the axial direction ; Vo = fluid velocity in the empty column, Vo = 03B6v. (*) Presented at the ISES Intemational Congress Atlanta, Georgia May 28, 1979. Greek symbols j = porosity ; i = characteristic lenght of the form of the particles i = Dp j6 for sphères ; p = gas density ; Il = viscosity ; 0 = fluid temperature ; 9+ = dimensionless fluid température ; ÂF = gas thermal conductivity ; À: = solid apparent thermal conductivity due to radiation, to solid contacts and to the neighbourhood of these contacts in which the fluid is considered at rest. Subscripts a = ambient ; o = side of the porous material exposed to the solar radiation. These quantities may be expressed in any set consistent units.
doi:10.1051/rphysap:01980001503042300
fatcat:udo5iykfb5f6bborbvtplsw7hu