UNSTEADY 3-DIMENSIONAL NATURAL-CONVECTION IN AN INCLINED AIR SLOT WITH A HEXAGONAL HONEYCOMB CORE

Unsteady three-dimensional natural convection heat transfer in an incl ined air slot with a hexagonal honeycomb enclosure is investigated num erically. The numerical methodology is based on an algebraic coordinat e transformation technique that maps the hexagonal cross section onto a rectangle. The transformed governing equations are solved with a con trol volume discretization scheme using a fully implicit method with t ime. The computations are performed for inclination angles in the rang e of 60 to 80 deg for Ra = 10(4), and in the range of 45 to 80 deg for Ra = 10(5), for Prandtl number of 0.7, and for a fixed aspect ratio o f H/L = 5. A conductive thermal boundary condition for the honeycomb s ide walls is considered. Both periodic and nonperiodic oscillating sol utions are obtained depending on the inclination angle and Rayleigh nu mber. The complex flow patterns are presented inform of particle traje ctory maps and are compared with the flow visualization results using microcapsulated liquid crystals.