Consider Problem 8.38. A mare realistic solution would Count for the resistance to heat transfer due to free convection in the paraflin during melting Assuming the tube surface n have

a uniform temperature of55°C and the paraffin to be an infinite, quiescent liquid,determine the convection coeflicient associated with the outer surface. Using this result and recognizing that the tube surface temperature is not known, determine the water outlet temperature, the total heat transfer rate,and the time required io completely liquefy the paraffin,for the prescribed conditions. Thermo physical proper-ties associated with the liquid state of the paraffin are \mathrm{A}=0.15 \mathrm{w} / \mathrm{m}+\mathrm{K}, \beta=\mathrm{s} \times 10^{-2} \mathrm{~K}^{-1}, \rho=77 \mathrm{k} \underline{\mathrm{m}}^{3}, y=5 \times 10^{-6} \mathrm{~m}^{2} / \mathrm{t}_{1} \text { and } \alpha=4 \mathrm{~s} 5 \times 10^{-2} \mathrm{~m}^{2} / \mathrm{s}