Work Problem 7.29, taking into account the increase in temperature of the water as it flows through
Question:
Work Problem 7.29, taking into account the increase in temperature of the water as it flows through the heat sink. Properties of water are listed in Problem 7.29, along with p = 995 kg/m3 and cp = 4178 J/kg · K.
Data From Problem 7.29
An array of electronic chips is mounted within a sealed rectangular enclosure, and cooling is implemented by attaching an aluminum heat sink (k 180 W/m K). The base of the heat sink has dimensions of w1 = w2 = 100 mm, while the 6 fins are of thickness t = 10 mm and pitch S = 18 mm. The fin length is Lf = 50 mm, and the base of the heat sink has a thickness of Lb =10 mm.
If cooling is implemented by water flow through the heat sink, with u∞ = 3 m/s and T∞ =17°C, what is the base temperature Tb of the heat sink when power dissipation by the chips is Pelec = 1800 W? The average convection coefficient for surfaces of the fins and the exposed base may be estimated by assuming parallel flow over a flat plate. Properties of the water may be approximated as k = 0.62 W/m · K, p = 995 kg/m3, cp = 4178 J/kg · K, v = 7.73 10–7 m2/s, and Pr = 5.2.
Step by Step Answer:
Fundamentals Of Heat And Mass Transfer
ISBN: 9780470501979
7th Edition
Authors: Theodore L. Bergman, Adrienne S. Lavine, Frank P. Incropera, David P. DeWitt