Inflow and Outflow Effects on Natural Convection in Partially Heated Vertical Parallel Plate Channels

In a vertical uniform wall heat flux channel in natural convective flow, the adiabatic. extensions can ameliorate or worsen the chimney effect and the corresponding heat transfer characteristics. The investigation set up in this paper is devoted to the detailed analysis of the aforementioned problem, by numerically solving the elliptic equations in an enlarged I-shaped computaional domain. The results presented herein have the aim to ascertain the discrepancies between the two investigated configurations, i.e. heated inlet and unheated inlet. The results are reported in terms of maximum wall temperatures and nondimensional induced flow rates. Further, some thermal and flow fields are shown. The channel Rayleigh number ranged between 10² and 10⁵ and the adiabatic extension between 0.0 and 19.0. The I-shaped domain allowed to evaluate the discrepancies in terms of stream function and thermal fields, particularly at the exit section. Moreover, it is shown the less the channel Rayleigh number the greater the influence of the adiabatic extensions. This influence is relevant up to four times the adiabatic extension respect to the heated section.