Abstract
Under forced convection and atmospheric pressure conditions, heat transfer characteristics were studied using the annulus channel of a heater rod with highly-wettable surface, Improvement of phase change heat transfer under boiling and condensation process requires that either liquid heated or vapor cooled can contact a heat transfer surface more effectively, while either a vapor layer or liquid film is formed repeatedly on the surface during boiling and condensation processes. As oxide semiconductor materials are known to the highly wettable, we made a TiO_2 coated surface. The Leidenfrost temperature for the TiO_2 coated surface was higher than for the uncoated surface. Under mss flux conditions of 600-1700kg/m^2s, the heater rod surface temperature for variable power input was measured. The results for the TiO_2 coated surface showed higher heat flux where the forced convection vaporization started and larger critical heat flux than for the uncoated surface.