超临界水中颗粒受Stefan流影响的数值模拟研究

Numerical Simulation Study on the Influence of Stefan Flow on Particles in Supercritical Water

超临界水气化(SCWG)技术由于其清洁及高效性而具有广阔的应用前景,反应过程中颗粒表面的Stefan流动不可忽略。本文主要开展在雷诺数10~200范围内的不同Stefan流方向以及强度对超临界水绕流固定球形颗粒的曳力以及传热过程影响的研究,同时对颗粒周围的流场以及速度和温度边界层进行了分析,结果表明,随着内向Stefan流强度的增大,曳力系数与努塞尔数均呈现增大的趋势,速度与温度边界层的厚度均呈现减薄的趋势;随着外向Stefan流强度增大,以上结论呈现相反趋势。

Supercritical water gasification(SCWG)technology has broad application prospects due to its cleanliness and high efficiency,and the Stefan flow on the particle surface during the reaction process cannot be ignored.In this paper,the influence of different Stefan flow directions and intensities on the drag and the heat transfer of supercritical water(SCW)cross flowing around a fixed spherical particle with Re numbers in the range of 10〜200 is studied.At the same time,the flow field and velocity and temperature boundary layer around the particle are analyzed.The results show that with the increasing intensity of the inward Stefan flow,the drag coefficient and Nusselt number both show an increasing trend,and the thickness of the velocity and temperature boundary layer shows a decreasing trend;the intensity of outward Stefan flow increases,and the above conclusion shows the opposite trend.