Consider a thermally developing flow in an initially hydrodynamically fully developed flow in a circular tube with 4-cm diameter. (a) For Re = 500 and 1000, estimate the thermal entrance length for...

Consider a thermally developing flow in an initially hydrodynamically fully developed flow in a circular tube with 4-cm diameter.

(a) For Re = 500 and 1000, estimate the thermal entrance length for air, water, glycerin, and mercury, all at 300 K. Assuming constant wall surface temperature, calculate the heat transfer coefficients for all the fluids once thermally developed flow is reached.

(b) Repeat part (a), this time assuming that the tube is 1.5 mm in diameter.