Chapter 11, Problem 11.66P

A cross-flow heat exchanger consists of a bundle of 32 tubes in a 0 $\text{0}{\text{.6-m}}^2$ duct. Hot water at 150°C and a mean velocity of 0.5 m/s enters the tubes having inner and outer diameters of 10.2 and 12.5 mm. Atmospheric air at 10°C enters the exchanger with a volumetric flow rate of $1.0{\text{ m}}^{\text{3}}\text{/s}$ . The convection heat transfer coefficient on the tube outer surfaces is ${\text{400 W/m}}^2\cdot \text{K}$ . Estimate the fluid outlet temperatures.