Numerical Analysis of Inverted Notched Fin Array Using Natural Convection

Abstract

Geometry and orientation plays an important role in natural convection heat transfer. For horizontal rectangular fin array a chimney flow pattern is developed due to density difference. This flow pattern creates a stagnant zone near central bottom region. That portion does not contribute much towards heat dissipation. This area is removed from fins and they became inverted notched fins. This modified geometry reduces material cost, material weight without hampering heat transfer rate. Numerical models are prepaid to investigate heat transfer characteristics in plane fins and inverted notched fins. This investigation is also extended over different types of notches and their effectiveness comparison. Fin spacing, fin height, fin length, heater input, percentage of area removed in the form of inverted notch are the parameters under consideration. This analysis is done numerically using CFD package (Fluent). It is found that the heat transfer coefficient of inverted notch fin array is 25% to 35% higher as compared with normal fin array. Also we found that the triangular shape notch gives better result than trapezoidal and rectangular shape notch.