Turbulent flow in a water-filled rectangular parallelepiped tank of an integrated solar collector is analyzed by means of a set of two and three dimensional simulations. The geometry and the working conditions of the prototype yield an aspect ratio of Γ = 6:68, Rayleigh number of Ra = 2:2 x 10 11 and a Prandtl number of Pr = 3:42.
Diff erent coarse DNS simulations and LES simulations using the dynamic Smagorinsky
SGS and WALE model are presented. Validity of the Oberbeck-Boussinesq approximation
is questioned. Heat transfer and first and second order statistics are studied.Peer ReviewedPostprint (published version