摘要
对圆管内变物性流体在加速流时考虑了非定常流的影响,采用新的湍流迁移模型,对换热过程和流动特性进行了数值模拟研究。与实验相比较,得到较一致的结果。模拟计算在很大的参量范围内进行,结果标明:努谢尔特数及阻力系数与其准静态时的量值的比值在所定义的无量纲特征时间上有一最小值;在加速流时变物性的影响是导致不稳定过程加大的因素。
The influence of variable thermophysical properties on the turbulent convection heat transfer with monotonously time-increasing mass flux in a tube was investigated numerically. The turbulent transfer model was based on the equation of eddy shear stress and unstability. The numerical calculations were compared with experiments. The calculation was made in a very large range of parameters. It is shown that there are minimum values of (?)quasi-st and Nu/Nuquasi-st varing with times. It is also shown that variable properties increase the transient effects.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2003年第5期821-824,共4页
Journal of Engineering Thermophysics
关键词
非定常湍流
变物性
对流换热
圆管
数值模拟
unstable turbulence
variable properties
convection heat transfer
tube
numerical simulation
