Engine oil enters a straight tube with a flow rate of 1 kg/s. The tube has a diameter of 5 mm and the surface temperature of the tube is maintained at 150˚C. The engine oil has an inlet temperature 52˚C and it is desired to heat the oil to a mean temperature of 80˚C at the exit of the straight tube. The properties of the engine oil are k = 0.139 W/m.K, Pr = 834, cp = 2072 J/kg.K and μ = 5.62 x 10-2 N.s/m2 Assume the flow is at fully developed region, determine: (a) The required length of the tube. (b) The rate of heat transfers from the tube to the engine oil.

Engine oil enters a straight tube with a flow rate of 1 kg/s. The tube has a diameter of 5 mm and the surface temperature of the tube is maintained at 150˚C. The engine oil has an inlet temperature 52˚C and it is desired to heat the oil to a mean temperature of 80˚C at the exit of the straight tube. The properties of the engine oil are k = 0.139 W/m.K, Pr = 834, cp = 2072 J/kg.K and μ = 5.62 x 10-2 N.s/m2 Assume the flow is at fully developed region, determine: (a) The required length of the tube. (b) The rate of heat transfers from the tube to the engine oil.

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.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.4P

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