In the present study, the fluid flow and heat transfer of a Cu-water nanofluid in a L-shaped enclosure with a baffle is numerically simulated using the Lattice Boltzmann Method (LBM). The implementation of different baffle combinations with the L shape cavity is the novel contribution of this study. The effect of baffle configuration on natural convection in different parameter ranges of Rayleigh number (${10}^3$–${10}^5$) and nanoparticle volume fraction (0–0.05) is investigated. Various baffle configuration cases are examined based on baffle length (L) and position (S). The baffled L shape results are also compared to the results obtained from a L shape without a baffle that were also achieved in this study and are validated with excellent agreement with existing data. Different models are used for evaluating the dynamic viscosity and thermal conductivity, to compare the effects of nanofluid properties. The results show that at low Rayleigh numbers (${10}^3$–${10}^4$), the addition of baffle always enhances natural convection. In high Rayleigh numbers (${10}^5$), only the longer baffle (L = 0.30 m) can improve natural convection regardless of its positioning. The longer baffle is always more effective with proper positioning (S = 0.4 m) and the case C baffle configuration (L = 0.30 m, S = 0.4 m) is the most effective in all conditions.

在本研究中，使用格子Boltzmann方法（LBM）数值模拟了带有挡板的L形外壳中的铜水纳米流体的流体流动和传热。带有L形腔的不同挡板组合的实现是这项研究的新贡献。挡板配置对瑞利数参数范围内自然对流的影响（${10}^3$–${10}^5$），研究了纳米粒子的体积分数（0-0.05）。根据挡板长度（L）和位置（S）检查各种挡板配置情况。带有挡板的L形结果也与没有挡板的L形获得的结果进行了比较，该结果在本研究中也得到了验证，并与现有数据高度吻合。使用不同的模型评估动态粘度和导热系数，以比较纳米流体性能的影响。结果表明，在低瑞利数下（${10}^3$–${10}^4$），增加挡板总是会增强自然对流。高瑞利数（${10}^5$），只有较长的挡板（L  = 0.30 m）才能改善自然对流，无论其位置如何。较长的挡板在正确定位时始终会更有效（S  = 0.4  m），而C挡板配置（L  = 0.30  m，S  = 0.4  m）在所有情况下都是最有效的。