Thermodynamics HW Solutions 190

Thermodynamics HW Solutions 190 - 1 1 2 1 6 1 5 4 3 2 = °...

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Chapter 15 Steady Heat Conduction ( b ) The thermal resistance network and the individual thermal resistances if the wall is constructed of bricks with air holes are T 1 R i R 1 R 2 R 3 R 4 T 2 R 6 R 7 R 5 2 2 2 ft 2426 . 0 0977 . 0 ft) 12 / 7 ( ft 0977 . 0 ) 12 / 25 . 1 ( ) 12 / 25 . 1 ( 9 = = = × = bricks airholes A A F/Btu h 729 . 7 ) ft F)(0.2426 Btu/h.ft. 40 . 0 ( ft 12 / 9 F/Btu h 77 . 511 ) ft F)(0.0977 Btu/h.ft. 015 . 0 ( ft 12 / 9 2 5 2 4 ° = ° = = = ° = ° = = = kA L R R kA L R R brick airholes Btu/h 2643 . 4 F/Btu h 7252 . 11 F ) 30 80 ( F/Btu h 7252 . 11 64 . 0 0677 . 1 244 . 7 0667 . 1 7068 . 1 F/Btu h 244 . 7 729 . 7 1 77 . 511 1 57 . 308 1 288 1 1 1 1
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Unformatted text preview: 1 1 2 1 6 1 5 4 3 2 = ° ° − = − = ° = + + + + = + + + + = ° = ⎯→ ⎯ + + + = + + + = ∞ ∞ total o mid i total mid mid R T T Q R R R R R R R R R R R R & Then steady rate of heat transfer through entire wall becomes Btu/h 3275 = = 2 ft 3906 . ft) 10 ( ft) 30 ( Btu/h) 2643 . 4 ( total Q & 3-33...
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This note was uploaded on 01/14/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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