MIXED CONVECTION HEAT TRANSFER IN TRUNCATED CONE ENCLOSURE AS SOLAR CONTAINER WITH INTERNAL CENTERED TRIANGLE OBSTACLE

Abstract

In this study, the mixed convection heat transfer of the air inside a truncated cone enclosure with aspect ratio of (0.75, 1.75, 2, 2.45 and 2.65) with centered triangle obstacle height varying by (0, 2.5, 5, 7.5, 10, 12.5 and 20 cm) and the heated wall inclination angles of (20o, 30o, 40o, 50o, 60o), the Richardson number in the range of (7 to 11) was investigated numerically. The results are addressed to automotive a suggested solar container with titled solar collector. The heat transfer from the heat source (inclined solar collector) of the enclosure walls is investigated for mixed convection as interaction of the forced convection flow between the inlet and outlet port in the bottom wall. The parameters of heat source, Reynolds number, obstacle height, enclosure aspect ratio, and left and right walls titled angles are considered in this work. The numerical simulation of the problem is carried out using commercial CFD code. The results are given in terms of the streamlines, isothermal, and the enclosure Nusselt number that characterizes the heat transfer from the heat source and from the interior fluid to the enclosure walls, respectively. The results show that the interaction of the main flow and the flow at the heated walls and the buoyancy force at the heated walls increased by using a triangular obstacle and by increasing the obstacle heights, it increased by 20% when using obstacle at position of (h=5 cm). Also, it is found that the Nu increased with increasing Re and the wall heat flux. The Nu increased with increasing Ri in the case of using (h=0 and 5 cm) but it decreased slightly in the other cases and showed that the minimum value of Nu present at a heated wall inclination of θ=50o but the maximum value at θ=30o.