Numerical simulation on natural convection and temperature distribution of supercritical water in a side-wall heated cavity

Abstract

In this work, natural convection and temperature distribution of supercritical water in a side-wall heated cavity are studied by numerical simulation. Different from ordinary single-vortex flow of perfect gas, supercritical water shows a thinner boundary layer with much higher velocity and finally forms a double-vortex natural convection pattern in the cavity. Moreover, for supercritical water, the temperature near the top wall of the cavity will exceed that of the heating wall, which is called overheating. Temperature, pressure, temperature difference between wall and fluid and aspect ratio will all affect velocity and temperature in the cavity. The mechanism analysis shows that the unique physical properties of supercritical water are vital reasons affecting the buoyancy driven flow boundary layer. The strong flow boundary layer will further lead to double-vortex flow pattern and overheating phenomenon, which will also affect natural convection pattern and temperature distribution.