【摘要】 采用Fluent计算软件对四叶片组合静态混合器内湍流换热进行数值模拟并与SK型静态混合器进行对比,结果表明,在104≤Re≤105范围内,前者的传热效率比后者提高约20%.运用场协同理论对结果进行了分析,新型静态混合器传热效率较高的主要原因为,在一个截面上有4个旋向与叶片旋向相同、旋涡半径近似等于叶片半径的纵向涡及4个旋向与叶片旋向相反、旋涡半径小于叶片半径的纵向涡,这些纵向涡能强化换热;与SK型静态混合器相比,新型静态混合器管内温度梯度基本相同,管内中心区二次流流速一定程度降低,而近壁区二次流流速差别较小,但速度场与热流场的协同程度得到明显改善.更多还原

【Abstract】 Four twisted elements were installed in a tube as static mixer and numerical simulation method was used to study its turbulent flow and heat transfer therein.The results show that compared with SK static mixer, the new static mixer could increase heat transfer efficiency by about 20% within 104≤Re≤105.The results were analyzed by applying the field coordination theory.The reason for the improvement with the new static mixer is that there are eight longitudinal vortices, which can promote heat transfer.The rotation of the adjacent vortices is opposite each other.The size of the vortices rotating in the same direction as the twisted elements is nearly equal to the radius of the twisted elements while the size of the vortices rotating in contrary to the direction of the twisted elements is slightly less than the radius.Compared with the SK static mixer, the coordination between velocity field and the temperature field is significantly improved, although the gradient of temperature and the velocity of secondary flow near wall are almost the same, and the velocity of secondary flow at the center of the tube decreases.更多还原