Abstract:
Two dimensional steady, mixed convection heat transfer in a trapezoidal cavity
with constant heat flux from the bottom wall while the isothermal moving top wall in the
horizontal direction has been studied numerically. Firstly the problem is defined as a two
dimensional enclosure .Control Volume based finite volume method (FVM) has been
used to discretize the governing differential equations. The pressure- velocity coupling in
the governing equations is obtained using the well known SIMPLE method for numerical
computations. The set of governing equations are solved sequentiil1ly. A second order
upwind differencing scheme is used for the formulation of the coefficients in the finitevolume
equations. All computations are done for a range of Richardson number, Ri from
0.1 to 10 and the aspect ratio, A has been changed from 0.5 to 2 for a fluid having Prandtl
number equal to 0.71 (air). First the optimum configuration of the trapezoidal cavity has
been obtained by changing the inclination angle, y of the side walls. Then the effect of
Richardson number, aspect ratio, and Rotation angle, <t> (30°,45 and 60°) of the optimum
trapezoidal cavity has been studied by changing the desired parameter. Results have been
presented in the form of streamline and isotherm plots as well as the variation of the
Nusselt number at the heat source surface under different conditions. The results shows
that with increasing Ri, the heat transfer rate increases as natural convection dominates.
The rotational angle of the trapezoidal cavity and the direction of the lid motion affect the
heat transfer rate significantly. Optimum heat transfer rate is obtained for aiding flow
condition having higher values of Ri.
