论文部分内容阅读
对局部热流作用下填充泡沫金属的旋转多孔盘内部离心力驱动流动和换热进行了数值研究,分析了旋转速度、固体骨架导热率以及孔隙率对旋转盘换热的影响.引入了热传递系数(定义为局部热流与盘面最大温差之比)评价旋转多孔盘的热传递能力.计算过程中将旋转盘内外流场进行解耦分析,即首先针对自由旋转盘表面的对流换热进行数值模拟以确定表面与环境之间的对流换热系数,然后作为边界条件进行旋转多孔盘内部离心力驱动流动和换热计算.在本文的研究条件下,模拟结果表明:随着旋转速度增加,离心力驱动的流动显著增强,转盘表面的最高温度降低且温度分布趋于均匀.采用导热性能好、孔隙率小的固体骨架也可以增强旋转多孔盘的热传递能力.在旋转多孔盘中,固相的导热模式占主导,流体相的流动对总体传热具有强化作用.
Numerical simulation of the centrifugal flow and heat exchange in a rotating porous disk filled with metal foam under localized heat flow was carried out. The effects of rotational speed, thermal conductivity of solid matrix and porosity on the heat transfer were analyzed. The heat transfer coefficient Which is defined as the ratio of the local heat flow to the maximum temperature difference of the disk surface, is used to evaluate the heat transfer capacity of the rotating porous disk.In the calculation process, the internal and external flow fields in the rotating disk are decoupled, that is, the numerical simulation of the convective heat transfer The convective heat transfer coefficient between the surface and the environment is then used as the boundary condition for centrifugal flow driving and heat transfer calculation in the rotating porous disk.In the condition of the research, the simulation results show that the centrifugal-driven flow significantly increases with the increase of the rotating speed Enhanced, the maximum temperature on the surface of the turntable decreases and the temperature distribution tends to be uniform. The use of a solid framework with good thermal conductivity and low porosity also enhances the heat transfer capability of a rotating porous disk. In a rotating porous disk, the thermal conductivity of the solid phase dominates , The flow of the fluid phase has a reinforcing effect on the overall heat transfer.