Water at a local bulk temperature of 24°C flows at 0.8 m/s through a smooth, 1.5-cm-ID...

Water at a local bulk temperature of 24°C flows at 0.8 m/s through a smooth, 1.5-cm-ID tube that is kept at 30°C and the flow is fully developed.

a) The system is extremely clean and quiet; therefore, the flow stays laminar regardless of the magnitude of ReD, until a noisy air compressor is turned on in the laboratory. Then the flow suddenly goes turbulent. Calculate the ratio of turbulent to laminar heat transfer coefficients. Use the Gnielinski correlation for turbulent flow.

b) Air at 227°C flows across the pipe at 20 m/s. Find the pipe wall temperature assuming the water flow to be turbulent, h from part a). You may assume a thin-walled pipe. This calculation is performed at the local point where the bulk temperature is 24°C.

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samet mamat answered 1 year ago

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