长时间流固耦合传热过程的快速算法

A fast algorithm for long-term fluid-solid conjugate heat transfer process

针对千秒级长时间流固耦合传热(CHT)过程求解问题,进一步提出一种基于准稳态流场的全局瞬态紧耦合传热的新型松耦合算法。交替使用单独对流体区域进行稳态流场求解的算法更新流场,以及同时对流固区域进行瞬态传热求解的算法计算瞬态温度场。该算法相对于传统流固松耦合算法,可以大大减小流场更新频率,进一步显著提高计算效率。以管内定来流速度空气连续300 s的强制对流瞬态加热过程为例,利用Fluent软件证明了该算法相对于瞬态紧耦合算法获得的管体结构温升最大偏差为5%,而计算耗时减小到14.8%。

Concerning the specific demands for solving problems of the long-term conjugate heat transfer （CHT） problem at the kiloseeond level, a new loosely coupled algorithm of the global tightly transient coupled heat transfer based on the quasi-steady flow field is put forward. The flow field is updated alone by steady al- gorithm and the transient temperature field of the fluid and solid regions are solved by transient heat transfer al- gorithm alternately. Compared to the traditional loosely coupled algorithm, the computational efficiency is fur- ther improved with the greatly reduced update frequency of the flow field. Taking a tube heated by inner forced air flow heating process for 300 s as an example, the results by Fluent software show that, compared to the tightly transient coupled calculation, the maximum wall temperature rise deviation is 5% while the computing time is reduced to 14.8%.