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 w,

= w, 100 mm, while the 6 fins are of thickness t= 10 mm and pitch S = 18 mm. The fin length is Lf = 50mm, and the base of the heat sink has a thickness of L, =10 mm. If cooling is implemented by water flow through the heatsink, with u = 3 m/s and T = 17°C, what is the base temperature T, of the heat sink when power dissipation by the chips is Pelee = 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, c, = 4178 J/kg - K, v =7.73 x 107 m²/s, and Pr 5.2.