Natural Convection along a Vertical Thin Cylinder with Uniform and Constant Wall Heat Flux

A theoretical investigation is carried out to study natural convection around a vertical thin cylinder, or a needle, heated at uniform and constant wall heat flux in order to compare the analytical solutions of the present work with previous experimental results. The local non-similarity solution with the first level of truncation, proposed by Minkowycz and Sparrow, is used. The temperature and velocity distributions are calculated for fluids with several Prandtl numbers. The analytical solutions of this work are compared to experimental results carried out with needles of diameters ranging from 0.6 to 1.5mm and fluids with Prandtl numbers in the range Pr = 0.7–730. The agreement is reasonable good