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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A long 20 cm diameter shaft made of stainless steel 304 comes out of an oven at a uniform temperature of 600°C. The shaft is then allowed to cool slowly in an environment at 200°C with an average heat transfer coefficient of h = 80 W/m².K. Determine [a] the temperature at the center of the shaft and [b] the temperature of the outer surface of the shaft 45 minutes after the start of the cooling Given: Find: Schematic: Assume: Property Data: k= 14.9 W/m°C p= 7900 kg/m³ Cp = 477 J/kg:K a= 3.95 x 10-6 m²/s
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