چكيده لاتين :
Th e present paper invest igates, numerically, the effect of the Grashof number to a Reynolds
number rat io (Gr/ Re), on fluid flow and heat t ransfer wit hin a vert ical channel for two cases:
Mixed (nat ural-forced) convect ion and combined mixed convect ion-radiat ion. The flow in the
channel is assumed to be two-dimensional, laminar and steady . The wall tem peratu re is defined
as a linear function of t he channel height . When dealing with the combined mixed convectionradiation
case, radiat ional propert ies have been taken into account , both for the walls and the
fluid. The fluid has a Prandtl number of 0.71 and it is radiat ionally assumed as a participat ing
medium. A comparison between the two cases at a constant Gr/Re is reported , so as to
invest igate the influence of radiation, as one of t he heat tra nsfer modes, more clearly. To
solve the governing equations (i.e., mass cont inuity, momentum and energy) the Finite Volume
method is employed and the SIM PLE algorithm is ado pted to couple the velocity and pressure
fields. T he radiat ive t ransfer equation is solved using the Discrete Ordinates Met hod, by ado pting
its 5.1 order quadrat ure scheme. The results for both cases are present ed as the profiles of axial
velocity across the channel width, axial cente rline velocity, bulk temperatu re and pressure versus
channel height .
