NUMERICAL INVESTIGATION OF A THREE-DIMENSIONAL LAMINAR MIXED CONVECTION FLOWS IN LID-DRIVEN CAVITY FOR VERY SMALL RICHARDSON NUMBERS
Laminar mixed convection in a three-dimensional lid driven cavity is numerically investigated. The top lid of the cavity is moving rightwards with a constant speed at a cold temperature. The bottom
wall is maintained at an isothermal hot temperature, while the other vertical walls of the cavity are assumed to be insulated. In this study the mass diffusion was not taken into account and
the fluid used was air. The flow and heat transfer behavior is studied for various Richardson number ranging from 5 × 10-5 to 3 × 10-4 at a fixed Prandtl number of 0.71 through analyzing
the local Nusselt number distribution at different sections inside the cavity. Lewis number Le is assumed to be unity and the buoyancy ratio parameter N is equal to zero. Computations were
done using an in-house code based on a finite volume method.
The results showed a good
agreement with previous two dimensional studies,
while the three dimensional study gives different
results at different sections inside the cavity. It is
observed that, the average Nusselt number “Av
Nu” on top and bottom surfaces decreases for all
sections inside the cavity with increasing
Richardson number. A correlation was formulated
for each section on both walls for “Av Nu” as a
function of “Ri” with a maximum error of 7.3%.