In this paper, natural convection heat transfer of supercritical water in rectangular enclosure has been investigated in various values of reduced temperature (0.955 1.205) and pressure (1.2 2.0). The right and left sides of enclosure considered to be isotherm with a temperature difference of , while the lower and upper sides of the enclosure was thermally insulated. The width of enclosure is 0.004m. Calculations were performed for Rayleigh number ( ), Prandtl number ( ). The values of Ra and Pr are governed by the fluid temperature and pressure which are controlled by reduced temperature( ) and reduced pressure ( ). Streamlines, isotherms and mean Nusselt numbers are presented. It is found that the temperature distribution and flow field are affected by the reduced temperature and pressure. The results also show that the maximum Nusselt number could be obtained at the same specification of geometry and temperature difference increases as the pressure reach the critical pressure.
Keyword: Natural convection, supercritical Water, reduced temperature and pressure