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22) Annular steel fins (k = 56.7 W/m·K) are attached to a steel tube that is 30 mm in external diameter. The fins are 2 mm tha and 15 mm long. The tube wall temperature is 350 K and the surrounding fluid temperature is 450 K with a heat-trans coefficient of 75 W/m2, K. There are 200 fins per meter of tube length. Calculate: (a) The fin efficiency (b) The fin surface area per meter of tube length. (c) The prime surface area per meter of the tube length. (d) The weighted efficiency of the finned surface. (e) The rate of heat transfer per meter of tube length. Ans. (a) 85%, (b) 0.9248 m. (c) 0.0565 m. (d) 86%. (e) 6330 w 231 A

Please help with a-e. The answers are given.

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Answer #1

15 m n i 2 1·ゴ5cm = etleche lensth oyea 0.62.5 cm 1.18 3-5 o.S 2 ho 4API ช่เo en n arca i 2 12-1923 W .

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