Análise numérica e investigação experimental da convecção natural laminar em um canal vertical com aquecimento discreto

Abstract

In this final course assignment, was performed a numerical analysis and experimental investigation of heat transfer by natural convection in laminar boundary layer on a vertical rectangular channel with discrete heating. This problem is associated with natural convection cooling of a 3D isothermal heater near the surface of a printed circuit board. The experimental investigation was performed at the Educational Laboratory of Thermal Sciences, using an Experimental Apparatus of a Natural and/or Forced Convection and a thermographic camera of high performance. The experimental uncertainties were calculated through simple sampling technique. The numerical analysis was performed at the Laboratory for Computer Research through simulations using ANSYS-FluentTM 14.5 software. The 3D governing equations with their boundary conditions were solved numerically by the Control Volume Method, within a single domain through a coupled procedure. The thermophysical properties of the fluid and the solids were considered constant, obtained from the library of the Engineering Equation SolverTM software (ESSTM). The evaluation of the thermal radiation losses were properly quantified in order to obtain the results for the heat transfer by natural convection. The results of numerical and experimental thermo-fluid-dynamics parameters of interest were obtained for Rayleigh numbers on the order of 106 considering the air as the cooling fluid. These results were compared, when possible, with the available literature considering an isothermal vertical flat plate and showed very good agreement.