中文摘要：

数值模拟了带均布纵肋同心套管内的三维导热和对流耦合换热，研究了肋高及肋数对摩擦阻力系数和平均Nusselt数（Nu）的影响．结果表明，肋高和肋数的变化对摩擦阻力系数和平均Nu都有显著影响，平均Nu随着肋数的增加有最大值；入口段Nu随肋高的增大而增大，充分发展段的Nu也随着肋高的增大而增大．

英文摘要：

A numerical simulation is performed for the three-dimensional laminar conjugated heat transfer in a concentric tube recuperator with longitudinal fins. The effect of the fin number and fin height on the friction and the mean Nusselt number Nu is simulated. The results gained show that the different fin heights and different fin numbers both have remarkable influence on the friction and the mean Nusselt number. The mean Nu changes with the change of fin number, within the scope of changing field, and reaches its max value. As the fin height increases, the Nusselt number at entrance, and the developed Nusselt number will increase aslo.