Chapter 8, Problem 8.89P

A coolant flows through a rectangular channel (gallery) within the body of a mold used to form metal injection parts. The gallery dimensions are $a\text{ = 90 mm and }b=\text{9}\text{.5 mm}$ , and the fluid flow rate is $1.3\times {10}^{-3}{m}^3/s$ . The coolant temperature is $\text{15}°\text{C}$ , and the mold wall is al an approximately uniform temperature of $\text{14}0°\text{C}$ .

To minimize corrosion damage to the expensive mold, it is customary to use a heat transfer fluid such as ethylene glycol, rather than process water. Compare the convection coefficients of water and ethylene glycol for this application. What is the tradeoff between thermal performance and minimizing corrosion?