A liquid is heated by passing it through a circular pipe (kpipe = 15W/mK, viscosity = 2.5×10-5 Pa-s, Cp = 1000 J/Kg-K, kliquid = 0.035 W/mK) of ID = 25mm and OD = 30mm with length L = 15 m. If the Reynolds No. is 79000. What is the outer surface average heat transfer coefficient?

A liquid is heated by passing it through a circular pipe (kpipe = 15W/mK, viscosity = 2.5×10-5 Pa-s, Cp = 1000 J/Kg-K, kliquid = 0.035 W/mK) of ID = 25mm and OD = 30mm with length L = 15 m. If the Reynolds No. is 79000. What is the outer surface average heat transfer coefficient? Correct Answer 83KW/m2K

Nusselt number = 0.023×(Re)0.8(Pr)0.4 here Pr = Cpxμ/k, density=1Kg/m3 Hence Pr = 0.7 Nu = h×OD/kpipe = 165, h = 83KW/m2K.
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