The present study deals with the conjugate mixed convection of a non-Newtonian nanofluid in an enclosure with a left thick side wall. We adopt Buongiorno’s non-homogeneous model to incorporate the effects due to Brownian motion and thermophoretic diffusion of the nanoparticles. The non-Newtonian behavior of the nanofluid is captured through the widely accepted power-law model. We employ the radial basis function (RBF)-based meshless numerical scheme for the simulation. In order to check the accuracy of the present numerical scheme, the simulated results are compared with the available numerical as well as experimental data. The excellent agreement of our results with the available ones ensures the capability of the newly adopted numerical tools to study the conjugate heat transfer problems. The results are presented by varying the pertaining parameters governing the undertaken conjugate mixed convection problem. Richardson number and Reynolds number are varied up to a moderate range with different permissible choices of the nanoparticle volume fractions, diameter of the nanoparticles, power-law index, and solid-to-fluid conductivity ratio, etc. The entropy generation and Bejan number are further evaluated to analyze the heat transfer characteristics. Results show that the degree of inhomogeneity of the nanoparticles depends strongly on the fluid behavior index. Rheological behavior of the nanofluid has substantial impact on the heat transfer rate and entropy generation, which can further be controlled through the value of the solid-to-fluid conductivity ratio. The pattern in Bejan number shows the predominance of the heat transfer irreversibility over the fluid friction irreversibility for all the cases considered in the study.

本研究涉及左厚侧壁外壳中非牛顿纳米流体的共轭混合对流。我们采用 Buongiorno 的非均匀模型来纳入布朗运动和纳米颗粒热泳扩散的影响。纳米流体的非牛顿行为是通过广泛接受的幂律模型捕获的。我们采用基于径向基函数（RBF）的无网格数值方案进行模拟。为了检查当前数值方案的准确性，将模拟结果与可用的数值和实验数据进行比较。我们的结果与现有的结果非常吻合，确保了新采用的数值工具能够研究共轭传热问题。结果是通过改变控制所进行的共轭混合对流问题的相关参数来呈现的。随着纳米颗粒体积分数、纳米颗粒直径、幂律指数和固液电导率等的不同允许选择，理查森数和雷诺数在一个适度的范围内变化。熵产生和贝詹数为进一步评估以分析传热特性。结果表明，纳米粒子的不均匀程度很大程度上取决于流体行为指数。纳米流体的流变行为对传热速率和熵产生有重大影响，这可以通过固液电导率值进一步控制。 Bejan 数的模式显示了在研究中考虑的所有情况下，传热不可逆性优于流体摩擦不可逆性。