A solid hemisphere of radius 5 cm to be cooled in air (at 20 o C, h=10 W/m 2 .K) from 200 oC to center of 150 oC, assume following sphere properties ρ=8500kg/m3, k=20W/m.K , C=400 J/kg.K a. List assumptions and justify selected method of solution b. How long does it take to cool the hemisphere? c. What is the temperature of the surface at end of cooling?

A solid hemisphere of radius 5 cm to be cooled in air (at 20 o C, h=10 W/m 2 .K) from 200 oC to center of 150 oC, assume following sphere properties ρ=8500kg/m3, k=20W/m.K , C=400 J/kg.K a. List assumptions and justify selected method of solution b. How long does it take to cool the hemisphere? c. What is the temperature of the surface at end of cooling?

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.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.3P

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