Carbon steel shafts of 0.2 m diameter and 1.2 m long are heat treated in a gas-fired furnace whose gases are at 1400 K and provide a convection coefficient of 90 W/m².K. The shafts enter the furnace at 300 K, and remain in the furnace until they achieve a centerline temperature of 850 K. (a) Show whether you can use the lumped capacitance method. (b) Find the time the shafts have to be in the furnace. (c) Determine total energy transfer during this time. Assume: p= 7800 kg/m³, k= 54.2 W/m.K, c= 541 J/kg.K, a = 1.21x10³ m²/s. Show all calculations.

Carbon steel shafts of 0.2 m diameter and 1.2 m long are heat treated in a gas-fired furnace whose gases are at 1400 K and provide a convection coefficient of 90 W/m².K. The shafts enter the furnace at 300 K, and remain in the furnace until they achieve a centerline temperature of 850 K. (a) Show whether you can use the lumped capacitance method. (b) Find the time the shafts have to be in the furnace. (c) Determine total energy transfer during this time. Assume: p= 7800 kg/m³, k= 54.2 W/m.K, c= 541 J/kg.K, a = 1.21x10³ m²/s. Show all calculations.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.10P: 3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the...

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