In this paper an analysis of natural convection in an enclosure filled with air and with opposite heated and cooled walls is performed; four different tilts of the cavity are investigated: θ = 0 π/6, π/3 and π/2. A complete definition of the velocity field in the cavity is obtained through PIV (particle image velocimetry) and is shown in terms of velocity contour maps and streamlines; the same results are obtained through numerical analysis and compared with the experimental ones: a very good agreement is found. In addition the thermal field is calculated and the value of the Nusselt number (Nu) next to the how wall is reported. A brief overview on a new PIV aspect is also discussed: since very small velocity fields are investigated, the effect of heating by the pulsed laser light becomes relevant, thus introducing a disturb on the measuring field that has never been considered for PIV, since it is generally treated as a completely nonintrusive technique.
PIV and numerical analysis of natural convection in tilted enclosures filled with air and with opposite active walls / Corvaro, Francesco; Paroncini, Massimo; Sotte, Marco. - In: INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER. - ISSN 0017-9310. - STAMPA. - 55:23-24(2012), pp. 6349-6362. [10.1016/j.ijheatmasstransfer.2012.06.003]