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.

在这项工作中，通过数值模拟研究了侧壁加热腔中超临界水的自然对流和温度分布。与理想气体的普通单涡流不同，超临界水显示出更薄的边界层和更高的速度，最终在腔内形成双涡自然对流模式。而且，对于超临界水，腔体顶壁附近的温度会超过加热壁的温度，称为过热。温度、压力、壁与流体之间的温差和纵横比都会影响腔内的速度和温度。机理分析表明，超临界水独特的物理性质是影响浮力驱动流动边界层的重要原因。