Determine the heat transfer coefficient for liquid bismuth flowing through an annulus (5-cm-ID, 6.1-cm-OD) at a velocity of 4.5 m/s. The wall temperature of the inner surface is 427°C and the bismuth is at 316°C. It may be assumed that heat losses from the outer surface are negligible.

GIVEN



FIND

The heat transfer coefficient

ASSUMPTIONS

Steady state

Heat losses from outer surfaces are negligible

SKETCH



PROPERTIES AND CONSTANTS

for bismuth at the bulk temperature of 316°C


The hydraulic diameter for the annual is given by



The Reynolds number based on the hydraulic diameter is



For liquid metals, the Nusselt number is given by

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