Question: Ethylene glycol-distilled water mixture with a mass fraction of 0.72 and a flow rate of 2.05 × 10-4 m3 /s flows inside a tube with an inside diameter of 0.0158 m and a uniform wall heat flux boundary condition. For this flow, determine the Nusselt number at the location x/D = 10 for the inlet tube configuration of
(a) bell-mouth and
(b) re-entrant. Compare the results for parts (a) and (b).
Assume the Grashof number is Gr = 60,000. The physical properties of ethylene glycol-distilled water mixture are Pr = 33.46, v = 3.45 × 10-6 m2 /s and µb/µs = 2.0.