Can you please briefly explain what is the one-term approximation method?
4-62 A 2-cm-diameter plastic rod has a thermocouple inserted to measure temperature at the center of the rod. The plastic rod (=1190 kg/m3, c=1465 J/kgK, and k=0.19 W/m-K) was initially heated to a uniform temperature of 70°C and allowed to be cooled in ambient air at 25°C. After 1388 s of cooling, the thermocouple measured the temperature at the center of the rod to be 30°C. Determine the convection heat transfer coefficient for this process. Solve this problem using the analytical one-term approximation method.
FIGURE P4-62
-62 A 2-cm-diameter plastic rod has a thermocouple inserted to measure temperature at the center of the rod. The plastic rod (=1190 kg/m3, c=1465 J/kgK, and k=0.19 W/m-K) was initially heated to a uniform temperature of 70°C and allowed to be cooled in ambient air at 25°C. After 1388 s of cooling, the thermocouple measured the temperature at the center of the rod to be 30°C. Determine the convection heat transfer coefficient for this process. Solve this problem using the analytical one-term approximation method.
Air, 25°C Plastic rod Thermocouple wires
FIGURE P4-62