A pure aluminum bar has a diameter of 15 cm and a length of 1.25 m....

A pure aluminum bar has a diameter of 15 cm and a length of 1.25 m. The rod is initially uniform in temperature at 300?C. The bar is now suddenly exposed to a convection environment at 50?C with h = 1250 W/m K. How long does it take the center to cool to a temperature of 80?C? (a) Determine if a lumped capacitance analysis is or is not appropriate. (b) Determine the cooling time assuming the lumped capacitance model is valid. (c) Finally, determine the time required for a point 0.5 cm from the surface to drop to 275?C

Expert Solution

samet mamat answered 2 years ago

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