Direct numerical simulation of flow and heat transfer in bidisperse gas-solid systems
Direct numerical simulation of flow and heat transfer in bidisperse gas-solid systems
复制标题
DOI：
10.1016/j.ces.2021.116645
复制
发表时间：
2021-04
影响因子：
4.7
通讯作者：
Zheqing Huang;Lingxue Wang;Yu Li;Qiang Zhou
中科院分区：
文献类型：
--
作者：
Zheqing Huang;Lingxue Wang;Yu Li;Qiang Zhou
采用浸没边界格子Boltzmann方法对颗粒直径比为1：2~1：4的双分散气固体系的流动与传热进行了数值模拟。对总体努塞尔数(Nu)进行了建模。结果表明，通过定义合适的当量直径，利用单分散关联式可以很好地预测从模拟结果得到的总体Nu。通过对单分散热传递关联式的修正，建立了预测每种物质的Nu的精确模型。由于大球和小球的相对固体体积分数比对每一种物质的Nu影响很小，因此修正项只是总固体体积分数和标度颗粒直径的函数。对模型的可预测性进行了评价。结果表明，该模型能较准确地估计出各物种的营养价值。
The flow and heat transfer in bidisperse gas-solid systems with particle diameter ratio ranging from 1:2 to 1:4 have been numerically investigated via an immersed boundary-lattice Boltzmann method. The modeling for the overall Nusselt number (Nu) is pursued. The results show that the overallNuobtained from the simulation results can be predicted well using the monodisperse correlations by defining an appropriate equivalent diameter. An accurate model to predictNufor each species is formulated through a correction to the monodisperse heat transfer correlations. Since the relative solid volume fraction ratio of large-to-small spheres has marginal influence onNufor each species, the correction term is only closed as a function of the total solid volume fraction and scaled particle diameter. The predictability of the model is evaluated. The results demonstrate that the model can give more accurate estimations forNuof each species.