In a heat exchanger, air flows over brass tubes of 1.8 cm ID and 2.1 cm OD that contain steam. The convective heat-transfer coefficients on the air and steam sides of the tubes are 70 W/(m2 K) and 210 W/(m2 K), respectively. Calculate the overall heat transfer coefficient for the heat exchanger (a) based on the inner tube area, (b) based on the outer tube area.GIVENAir flow over brass tubes containing steamTube diametersInside (Di) = 1.8 cm = 0.018 mOutside (Do) = 2.1 cm = 0.021 mConvective heat transfer coefficientsAir side (hc ) = 70 W/(m2 K)Steam side (hi) = 210 W/(m2 K)ASSUMPTIONSThe heat transfer coefficients are uniform over the transfersurfaces

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D,=2.1 cm D- 1.8 cm Stean Alr