二维蜂窝多孔金属夹层圆柱壳的传热性能数值模拟研究

Simulation Analysis of Heat Transfer Performance of Two-Dimensional Cellular Metal Sandwich Cylindrical Shell

文章以脉冲爆震发动机的爆震燃烧室为原型,分析二维蜂窝多孔金属夹层圆柱壳的传热问题。文中将二维蜂窝孔在管壁径向按放射状布置,将内表面设置成高温边界条件来模拟实际燃烧室工作情况,空气从蜂窝孔一侧流经材料与圆柱壳内表面充分换热后流出起到冷却作用;通过数值模拟分析了六边形孔、矩形孔和三角形孔按照不同的连结排布在夹层圆管中的传热性能与相对密度的关系;同时还研究了夹层层数对传热性能的影响。结果表明六边形孔排布的传热性能要优于其它拓扑构型;传热性能随单胞层数增加而增大,当层数达到一定值后,传热性能基本上保持不变。

Considering a prototype of the detonation combustor of a pulse detonation engine（PDE）,we investigate by using numerical simulation the heat transfer performance of the sandwich cylindrical shell with two-dimensional honeycomb metal core.The open-hole direction of honeycomb metal core is parallel to the axial direction of the PDE tube,which affords the facilitation of the forced air convection with the open channel to remove a heat flux impinging on the inner surface of the metallic sandwich cylindrical shell.In the radial direction,the cells are arranged semi-periodically,but,in the loop direction,they revolve periodically.The heat transfer performances of the honeycomb metal with hexagonal,rectangular and triangular geometries are obtained respectively by numerical simulation.The effects of geometry,relative density and number of layers on the heat transfer performance are consecutively discussed.The simulation results,presented in Figs.4,5 and 7 and Tables 5 and 6,and their discussion show preliminarily that：（1） the hexagonal geometry is the most desirable among the five geometries;（2） there is an optimal relative density of the honeycomb metal for maximum heat transfer performance;（3） the heat transfer performance improves as the number of layers increases,however the heat transfer performance stabilizes when the number of layers is larger than a certain value.