An experiment was conducted to determine surface convective heat-transfer Example 4.25 coeffi cient for peas being frozen in an air-blast freezer. For this purpose, a metal analog of peas was used....

An experiment was conducted to determine surface convective heat-transfer Example 4.25 coeffi cient for peas being frozen in an air-blast freezer. For this purpose, a metal analog of peas was used. The analog was a solid copper ball with a diameter of 1 cm. A small hole was drilled to the center of the copper ball, and a thermocouple junction was located at the center using a high-conductivity epoxy. The density of copper is 8954 kg/ m³
, and its specific heat is 3830 J/(kg K). The copper ball (at a uniform initial temperature of 10°C) was hung in the path of air flow (at- 40°C) and the center temperature indicated by the thermocouple was recorded. The following table lists the temperature at one-minute intervals for 14 minutes. Determine the surface heat-transfer coeffi cient from these data.