Chapter 8, Problem 8.90P

An electronic circuit board dissipating $\text{5}0\text{ W}$ is sandwiched between two ducted, forced-air-cooled heat sinks. The sinks are $\text{15}0\text{ mm}$ in length and have 20 rectangular passages $\text{6 mm × 25 mm}$ . Atmospheric air at a volumetric flow rate of $\text{0}{\text{.060 m}}^{\text{3}}\text{/s and 27°C}$ is drawn through the sinks by a blower. Estimate the operating temperature of the hoard and the pressure drop across the sinks.