A Comparison of Tapered and Straight Circular Pin-Fin Compact Heat Exchangers for Electronic Appliances

Pin-fin heat exchangers are widely used for cooling of thermally laden electronic components. In the present paper, tapered pin fins with circular cross section placed horizontally in the staggered arrangement on a heated base plate are investigated numerically under the steady-state conditions. Aluminum is considered to be the material of pin fins. The performance of a heat exchanger has been assessed for four inlet flow velocities. Two angles of tapered pin fins have been considered, namely, 2° and 4°. Their performances are further compared with that of straight circular pin fins. It has been observed that though the performances of straight circular and 2° tapered pin fins are approximately the same, at high velocities the 2° tapered pin-fin arrangement provides an improved heat transfer characteristics compared to its circular counterpart for the same pressure drop (or the pumping power). This trend is reversed at low velocities with straight circular pin fins providing a better heat transfer coefficient per unit pressure drop. Though a smaller pressure drop was observed in 4° tapered pin-fin arrangement at all velocities, its heat transfer coefficient per unit pressure drop was smaller as compared to other two arrangements.