Chapter 8, Problem 8.27P

In the final stages of production, a pharmaceutical is sterilized by heating it from 25 to $\text{75}°\text{C}$ as it moves at $0.\text{2 m}/\text{s}$ through a straight thin—walled stainless steel tube of $\text{12}.\text{7}-\text{mm}$ diameter. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the tube. If the tube is 10 m long. what is the required heat flux? It fluid enters the tube with a fully developed velocity profile and a uniform temperature profile. what is the surface temperature at the tube exit and at a distance of $0.\text{5 m}$ from the entrance? Fluid properties may be approximated as $\rho =1000{\text{kg/m}}^3,c_p=4000\text{J/kg}\cdot \text{K,m}=2\times {10}^{-3}\text{kg/s}\cdot \text{m,k}=0.8\text{W/m}\cdot \text{K}$ , and $Pr=\text{ 1}0$ .