Given: Liquid refrigerant $R-134$ a flows with a mean velocity of $u-0\mathrm{.}04\frac{m}{s}$ through a duct that is $1$ cm by $0\mathrm{.}5$ cm in cross section. Consider the flow to be fully developed and the surface of the duct to be nearly constant temperature.

Find: Calculate the average heat transfer coefficient and the friction factor for the flow of refrigerant through the rectangular duct.

Assume: Use these properties for the refrigerant: $=1199\mathrm{.}7k\frac{g}{m^3},c_2=1\mathrm{.}432\frac{k}{k}gK,v=0\mathrm{.}1588{10}^{-6}\frac{m^2}{s},Pr=3\mathrm{.}4,$ and $k=0\mathrm{.}0803\frac{W}{m}K.$