A new drag force and heat transfer correlation derived from direct numerical LBM-simulations of flown through particle packings
A new drag force and heat transfer correlation derived from direct numerical LBM-simulations of flown through particle packings
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DOI：
10.1016/j.powtec.2019.01.028
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发表时间：
2019-03
影响因子：
5.2
通讯作者：
B. Kravets;T. Rosemann;S. R. Reinecke;H. Kruggel-Emden
中科院分区：
文献类型：
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作者：
B. Kravets;T. Rosemann;S. R. Reinecke;H. Kruggel-Emden
在目前的工作中，热晶格-玻尔兹曼方法 (TLBM) 用于研究对流扩散问题并确定不同密度随机堆积颗粒的平均努塞尔数。为了进行数值研究，得出了 3D TLBM 框架。其中，流体动力学方面通过 D3Q19 多重弛豫时间 (MRT) 碰撞算子和插值反弹方案进行求解。对于热侧，应用两种不同的碰撞算子，即 Bhatnagar-Gross-Krook (BGK) 和 MRT，并进行相互比较。此外，通过比较热侧的 D3Q7 和 D3Q19 模型来检查 LBM 网格结构的影响。然后研究平面和弯曲边界的热扩散和对流扩散问题，并根据解析解（如果可用）或与已建立的闭合相关性进行比较来验证结果。此外，选择最佳碰撞算子和边界条件（关于数值精度和稳定性）来研究不同静态、随机粒子/流体系统内不同孔隙率、雷诺数和普朗特数的对流扩散相间传热。将获得的结果与已发布的相关性进行比较。此外，提出了在ε=0.6−1、Rep=20−500 和Pr=0.5−1.5 范围内的随机粒子堆积中阻力和粒子平均努塞尔数的新闭合相关性。
In the present work a thermal Lattice-Boltzmann method (TLBM) is applied to study convection-diffusion problems and to determine averaged Nusselt numbers for particles being part of differently dense random packings. For the carried out numerical investigations a 3D TLBM framework is derived. Therein the hydrodynamic side is solved with a D3Q19 multiple-relaxation-time (MRT) collision operator and interpolated bounce back schemes. For the thermal side two different collision operators namely Bhatnagar-Gross-Krook (BGK) and MRT are applied and compared against each other. Furthermore, the impact of the LBM mesh structure is examined by comparing a D3Q7 and a D3Q19 model for the thermal side. Thermal diffusion and convection-diffusion problems for plane and curved boundaries are then studied and the results are validated against analytical solutions, when available or compared to established closure correlations. Furthermore, the best collision operator and boundary conditions - regarding numerical accuracy and stability - are selected to investigate convective-diffusive interphase heat transfer inside different static, random particle/fluid systems for varying porosities, Reynolds and Prandtl numbers. Obtained results are compared against published correlations. In addition a new closure correlation for drag forces and particle averaged Nusselt numbers in random particle packings in the range ofε= 0.6 − 1,Rep= 20 − 500 andPr= 0.5 − 1.5 is proposed.