Investigation of the radial heat transfer from a constant heat flux of a vertical linear heat source
Sprache des Vortragstitels:
Minisymposium Verfahrenstechnik 2014
Sprache des Tagungstitel:
The focus of this study is the radial heat transfer from a constant heat flux of a vertical linear heat source in form as heat conduction and natural convection in Newtonian and non-Newtonian fluids. A number of experimental analyses were performed to establish a thermal profile by using an apparatus of two interlocking standing steel cylinders with different diameters. The medium of the inner cylinder transfers a constant amount of heat to the outer medium of the larger cylinder. The first analyses were performed with water, while further examinations were done by using different water based systems by adding organic additives such as high molecular weight polysaccharides or inorganic substances for instance sand. Additions of these substances lower or inhibit the heat transfer as form of natural convection, as it occurs in pure water, while heat passes through the respective medium partly by conduction. According to the experimental measurements the heat flux density [W m-2] and the heat transfer coefficient k [W m-2K-1] were determined for the various media. Further dimensionless numbers such as the Nusselt number (Nu) and the Rayleigh number (Ra) were calculated.