圆形和方形双斜向流线型内肋管内对流换热的数值模拟与分析

Numerical Simulation and Analysis of the Convection Heat Transfer in Circular and Square Double-Inclined Streamline Ribs(DISR)Tubes

使用FLUENT对圆形和方形双斜向流线型内肋换热管进行了数值模拟研究.结果表明,圆形和方形双斜向流线型内肋管的内肋在肋长、肋倾角、肋高度和肋间距上存在最优值,l=38mm,α=45°,h=2.5mm,P=60mm和l=32mm,α=45°,h=4mm,P=60mm,同功耗强化指标PEC均呈先升后降的趋势.从管壁表面换热系数、管内场协同角和PEC评价指标3个方面,比较圆形DISR管和方形DISR管的对流换热性能,分析了圆形DISR管优于方形DISR管的原因.

A numerical simulation was carried out for the convection heat transfer in circular and square doubleinclined streamline ribs （DISR） tubes by FLUENT. The results showed that the optimal parameters were： rib length （l=38 mm）, rib inclined degree （a=45°） , rib height （h=2. 5 mm） and rib pitch （P=60 mm） for circular DISR tubes, and rib length （l = 38 mm）, rib inclined degree （a= 45°） , rib height （h = 4 mm） and rib pitch （P= 60mm） for square DISR tubes. The PEC number increased firstly and decreased finally. The performance of convection heat transfer of circular and square DISR tubes was compared from the perspectives of wall surface heat transfer coefficient, field synergy angle and PEC number, and the reason of better heat transfer performance of circular DISR tubes than that of their square counterparts was discussed.