低速下空气横掠翅片管换热规律的数值研究

用三维适体坐标的网格生成技术对翅片管散热器进行了低速下流动和换热的数值模拟，得到了流速与换热系数的关系，以及不同流速下翅片管流动与换热的温度场、速度场和速度与温度梯度的夹角场，并首次利用场协同原理进行了分析。结果表明：当流速很低时，速度与换热系数几乎成线性变化，场的协同性很好；随着速度的增加，场的协同性变差，换热系数随速度增加的程度减弱。

Numerical Study on Heat Transfer of Air Across Finned Tube at Low Speeds

Numerical methods of three dimensional grid generation with body-fitted coordinates were adopted to simulate the fluid flow and heat transfer across a finned single tube at low speeds. The relation between mean flow velocity and the heat transfer coefficient, the velocity field, the temperature field and the angle field between velocity and temperature gradient were obtained. The results are as follows: at low velocity, the heat transfer coefficient is nearly proportional to the average velocity and velocity and temperature gradient are in good synergy. With the increase in velocity, the degree of the synergy decreases, hence, the increase tendency of h with U also decreases.