Experimental and numerical investigation of natural convection for a fully closed cabinet subject to chimneys

This study focuses on the improvement of the natural convection heat dissipation performance of a fully closed cabinet. Both experiments and simulations are performed for eight different cases to examine the effect of the heat sink with chimney effect, baffle, ceiling and ceiling angle with different perforation. A heat sink is introduced to form dual chimneys to separate/facilitate the airflow circulation in the interior and exterior of the cabinet. The heat generation is 90 Watts and the exterior ambiance is around 25 °C. The chimney effect of the heat sink with baffle improved the airflow circulation by reducing 11–14% of the thermal resistance (TR) than the reference case. TR was found to increase with the increase in baffle height and decrease with the increase of perforation and ceiling angle, respectively. The overall analysis recommends the optimized parameters namely, baffle length 175 mm, 20 mm opening height under the baffle, length of ceiling plate to be 75 mm with 20% perforation, ceiling height 75 mm with 20% perforation and 27-degree ceiling angle. The optimized design reduced the TR by 17.9% than the base case standardizing the natural convection potential that can enhance the airflow and heat transfer.