18-51 A long 35-cm-diameter cylindrical shaft made of stainless steel 304 (k = 14.9 W/mK, p = 7900 kg/m³, cp = 477 J/kg . K. and a = 3.95 x 10-6 m²/s) comes out of an oven at a uniform temperature of 500°C. The shaft is then allowed to cool slowly in a chamber at 150°C with an average convection heat transfer coefficient of h=60W/m² K Determine the temperature at the center of the shaft 20 min after the start of the cooling process. Also, determine the heat transfer per unit length of the shaft during this time period. Solve this problem using the analytical one-term approximation method Answers: 486°C 22.270 kl

18-51 A long 35-cm-diameter cylindrical shaft made of stainless steel 304 (k = 14.9 W/mK, p = 7900 kg/m³, cp = 477 J/kg . K. and a = 3.95 x 10-6 m²/s) comes out of an oven at a uniform temperature of 500°C. The shaft is then allowed to cool slowly in a chamber at 150°C with an average convection heat transfer coefficient of h=60W/m² K Determine the temperature at the center of the shaft 20 min after the start of the cooling process. Also, determine the heat transfer per unit length of the shaft during this time period. Solve this problem using the analytical one-term approximation method Answers: 486°C 22.270 kl

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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Concept explainers

Conduction and Convection

When energy travels from one object to another it is said to have undergone heat transfer. Heat transfer is nothing but the transfer of thermal energy or internal energy from one thing to another, like e.g., when a vessel with water, kept on top of a burner, heats up because of the flame underneath it.

Question

18-51 A long 35-cm-diameter cylindrical shaft made of stainless steel 304 (k = 14.9 W/mK, p = 7900 kg/m³; cp = 477 J/kg - K,
and a = 3.95 x 10-6 m²/s) comes out of an oven at a uniform temperature of 500°C. The shaft is then allowed to cool slowly in
a chamber at 150°C with an average convection heat transfer coefficient of
h = 60W/m².K
Determine the temperature at the center of the shaft 20 min after the start of the cooling process. Also, determine the heat
transfer per unit length of the shaft during this time period. Solve this problem using the analytical one-term approximation
method. Answers: 486°C, 22,270 kJ

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