振动圆管外对流换热特性的场协同机理

摘要

The research on heat transfer gives a rough conclusion that vibration can enhance heat transfer near the vibrating surface, and its mechanism basically depends on the boundary layer theory that vibration reduces the thickness of boundary layer. Field synergism theory in convective transfer interprets convective enhancement approach by the maxing principle and matching principle with quantitative indicators. In this study, the convective heat transfer characteristics of vibrating cylinder is investigated using maxing principle and matching principle of field synergism. The properties of working fluid are similar to those of water, the cylinder vibrates in simple harmonic vibration with frequency of 15 Hz, the amplitude is 1 mm, and the turbulence model is RNG k-ε model. The study shows that the relation between heat transfer and synergism performance interprets the enhancement of heat transfer outside the vibrating cylinder. The matching principle and maxing principle in synergism theory shows that the improvement is from the increase of heat transfer coefficient. Synergism angle cosine has maximum values on position phase 0° and 180° and minimum values on 90° and 270°, and increases when the time phase is close to the equilibrium moment. The synergism matching performance corresponds to the angle cosine value.Heat transfer coefficient distribution pattern is consistent with the angle cosine value and matching coefficient.%数值模拟了振动圆管外的对流换热,通过数据后处理分析了振动圆管外对流换热特性与场协同性能间的联系,从场协同原理的大值原则与匹配性原则上对振动圆体外表面传热的规律特性作了解释.振动圆管外的场协同角余弦值在面相位0°与180°处最大,在90°与270°处最小,并且随着时相位靠近平衡位置,其面上各点的场协同角余弦值逐渐变大.场协同匹配性能的分布规律与场协同角余弦值的分布基本相同.振动圆管外的对流传热系数分布规律与场协同余弦值及场协同匹配系数的分布规律一致,表明可以使用场协同原理阐述振动圆管外的对流换热规律.