Experimental study of natural convection in a cylindrical cavity

Abstract

The flow established in a cylindrical cavity heated and cooled on its sidewalls, insulated on the upper and lower walls, was studied experimentally. Using a laboratory scale model and using water as convective flow, thermal measurements were made and simultaneously visualization of the flow established in the cavity was carried out. Temperature variations in the axial direction were measured, which generate significant thermal gradients in this direction. The range of the Rayleigh number studied was between 1.2×107 and 3.2×108, which corresponds to the upper limit of the laminar regime. The convective transfer coefficient on the inner surface of the sidewall was determined from temperature measurements. The flow was visualized using photographic records and videos showing the evolution of the circulation pattern. The processing of the visual records allowed the differentiation of several regimes, the boundary layer, the mixing regions and the central core. Velocity values were estimated, and the extension of these regions was defined.