Unsteady heat transfer from a sphere in a uniform cross-flow
Unsteady heat transfer from a sphere in a uniform cross-flow
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DOI：
10.1063/1.1416886
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发表时间：
2001-11
影响因子：
4.6
通讯作者：
S. Balachandar;M. Ha
中科院分区：
文献类型：
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作者：
S. Balachandar;M. Ha
考虑三种不同类型的非稳态传热问题：第一个考虑球形颗粒在均匀等温环境流动下的自由热演化，其中颗粒温度向环境流动温度演化；第三个考虑球形颗粒的自由热演化，其中颗粒温度向环境流动温度演化。第二个考虑了响应颗粒温度突然跳跃的不稳定传热问题；第三个考虑由等温环境流中的振荡颗粒温度引起的振荡传热。在每种情况下，都会考虑雷诺数或佩克莱数的范围。第一组模拟表明，自由热演化下球形颗粒的不稳定传热可以通过有效的努塞尔数来描述，至少在本研究考虑的参数范围内是这样。非稳态自由热演化下的有效努塞尔数与稳态对应值存在偏差，其差异取决于周围流体与颗粒之间的热容比。现有的...
Three different types of unsteady heat transfer problems are considered: the first considers the free thermal evolution of a spherical particle subjected to a uniform isothermal ambient flow, where the particle temperature evolves toward the ambient flow temperature; the second considers the unsteady heat transfer problem in response to a sudden jump in the particle temperature; and the third considers oscillatory heat transfer due to oscillatory particle temperature in an isothermal ambient flow. In each case a range of Reynolds or Peclet number is considered. The first set of simulations show that unsteady heat transfer from a spherical particle under free thermal evolution can be described by an effective Nusselt number, at least over the range of parameters considered in this study. The effective Nusselt number under unsteady free thermal evolution deviates from the steady-state counterpart and the difference depends on the heat capacity ratio between the surrounding fluid to the particle. The existen...