Abstract
A test apparatus was designed and built to obtain heat transfer data of solar saltand other molten salts in the future, though future work will require the completion and
operation of the apparatus to obtain molten salt results. Garimella’s equations typically
over predicted heat transfer coefficients in comparison to CFD solutions, with an overall
percent error of 296% in the range of 325oC ≤ Tin ≤ 505oC. Lower heat transfer coefficients
were observed at higher temperatures due to decreasing viscosity and Prandtl numbers.
Lower local heat transfer coefficients are observed in the flutes of the fluted tube, and are
attributed to lower local velocities and differences between surface temperature and the
average fluid temperature. Rapid hydrodynamic and thermal development in the fluted
tube was observed when compared to predicted entrance lengths of a plain tube with an
equal hydraulic diameter. Heat transfer enhancement at a length of 6 inches is 1.34, but is
expected to be much larger at fully developed flow for both fluted and plain tubes.