缩放椭圆管结垢对换热场协同的影响

Effect of fouling on heat transfer field synergy in alternating elliptical axis tubes

针对结垢厚度分别为0.5、1.0、1.5、2.0mm的圆管及交叉缩放椭圆管进行数值模拟,分析在雷诺数Re分别为10 000、12 000、18 000、24 000、30 000的流动状态下,污垢对速度场和温度场及其协同角、协同数的影响,并对圆管及交叉缩放椭圆管进行比较。结果表明:交叉椭圆管内场协同数随着Re的增加而减小,随着污垢厚度的增加而增大,而平均协同角则相反;沿管长方向场协同数逐渐减小,对于每个过渡段,场协同数有2次最大峰值和2次最小峰值;交叉缩放椭圆管的平均场协同数大于圆管,平均协同角小于圆管。

Numerical simulation on circle tube and alternating elliptical axis tube with fouling thickness of0.5mm,1.0mm,1.5mm and 2.0mm was carried out to analyze the effects of fouling on velocity field,temperature field,synergy angle and and synergy number,under conditions with Renolds number of10 000,12 000,18 000,24 000 and 30 000.Moreover,comparative analysis on circular tube and alternating elliptical axis tube was performed.The results indicate that,in the alternating elliptical axis tube,the field synergy number decreases with the increasing Reynolds number while increases with the fouling thickness.The average synergy angle has the opposite changes.Along the tube length,the field synergy number decreases gradually,it has two maximum peaks and two minimum peaks within each transition section.The alternating elliptical axis tube has greater mean-field synergy number but smaller average synergy angle than the circle tube.