阶梯型百叶窗翅片的热力性能分析

Thermal hydraulic performance analysis of inclined louvered fin

针对阶梯型百叶窗和百叶窗翅片分别建立三维模型，通过数值模拟方法得到两类翅片流动传热单元内的空气流场、温度场与压力场分布，据此比较分析二者的热力性能差异．结果表明：阶梯型百叶窗翅片的传热因子j和摩擦因子f均高于普通百叶窗翅片，雷诺数Re在558～2510范围内，前者j因子较后者高出29．8％～18．6％,f因子增加39．7％～58．9％；雷诺数较低时，阶梯型百叶窗翅片的热力性能指标j／f^1/3力高出百叶窗翅片最高达16％；雷诺数高于2232时，二者的差别则低于3．2％；阶梯型百叶窗翅片在低雷诺数条件下热力性能提高明显，对于较高的雷诺数，其优势减弱显著．

Three-dimensional models of louvered fin and inclined louvered fin in fin-tube radiator were respectively established to investigate the fluid flow, the temperature and pressure fields when air flows over the two kinds of fins, and the differences of thermal hydraulic performance between them were ana- lyzed. The calculated results show that the heat transfer factor and the friction factor of inclined louvered fin are both higher than those of louvered fin. Compared with the louvered fin, when Reynolds number varies from 558 to 2 510, j factor of the inclined louvered fin is increased from 29.8% to 18.6% , while f factor is increased from 39.7% to 58.9%. When Reynolds number is small, the maximum difference between the two kinds of j/f^ 1/3 factors is over 16%. When Reynolds number is over 2 232, the differences is not more than 3.2%. It indicates that the inclined louvered fin has better thermal hydraulic performance than that of louvered fin, especially under the condition of small Reynolds number.