Two horizontal steam mains with diameters 5 cm and 15 cm are to be laid in a boiler house that any mutual heat effect is precluded. The mains are at the same surface temperature of 500 degree Celsius whilst the ambient air is at 50 degree Celsius. Workout the ratios of the heat transfer coefficients
(a) 0.136
(b) 1.316
(c) 2.136
(d) 3.136
I had been asked this question by my college professor while I was bunking the class.
Question is taken from Correlations for Free Convection in division Diffusion in Solids and Molecular Diffusion in Fluids of Mass Transfer