90°交叉弯管混合流场的数值模拟与分析

从基本的数学模型出发,描述了弯管流场的分布规律。采用FLUENT 5.5商业软件对90°交叉弯管内水的温度场进行了模拟求解,并讨论了小管位置与管径的变化对大管内混合流场的影响。结果表明:管路的出口平均温度随小管入口Re数的增加而增大,但增大的趋势逐渐趋缓;小管的不同位置也会影响管路中流场的混合和传热效果,建议其α角在45~60°之间,在此范围外,传热效果变差,并且出口会有明显的温度分层现象。

Numerical simulation and analysis of flow field of 90°elbow pipe

The distribution regularities of flow field of elbow pipe is discussed on the basis of mathematical model.In addition,the temperature field of a 90° elbow pipe is calculated by means of FLUENT5.5.Finally the effect of the position and pipe diameter of the small pipe is analyzed.It is concluded that: the mean temperature at outlet increases along with the augmentation of Re at the small pipe inlet,but its rising trend turns out to be slow.The position of small pipe also has effect on the mixture of flow field and heat transfer.The recommended α for the small pipe is 45～60°.Otherwise,the heat transfer turns to be worse and there is obvious stratification at pipe outlet.