Abstract

The objectives of the present research work are the three-dimensional computational analysis and predictions on double-diffusive natural convection in a cubic cavity filled with Cu–Al₂O₃/water micropolar hybrid nanofluid. The governing equations are carefully modified employing vorticity–vector potential formulation and are solved by the finite volume method. Performance enhancement of Cu–Al₂O₃/water micropolar hybrid nanofluid is judiciously compared with the Cu/water simple nanofluid. Besides, the influences of concentration of nanoparticles, Rayleigh number, buoyancy ratio, and micropolar vortex parameter on the flow field and heat transfer are critically analyzed. The results show that heat and mass transfer rates are lower for a micropolar nanofluid model when compared to the pure nanofluid model. The hybrid micropolar nanofluid displays more heat and mass transfer rates for thermal buoyancy-dominated zones when compared with traditional nanofluid. Conversely, the heat and mass transfer rates are decreased when using micropolar hybrid nanofluid for the solutal-dominated regime. The enhancement of micropolar viscosity parameter results in a decrease of average Nusselt and Sherwood numbers which are more perceptible in the thermal buoyancy-dominated flow.

摘要

本研究工作的目标是对填充有 Cu-Al ₂ O ₃ /水微极混合纳米流体的立方腔中的双扩散自然对流进行三维计算分析和预测。控制方程使用涡量-矢量势公式进行了仔细修改，并通过有限体积方法求解。Cu-Al ₂ O _{3 的}性能提升/水微极性混合纳米流体与铜/水简单纳米流体进行了明智的比较。此外，批判性地分析了纳米粒子浓度、瑞利数、浮力比和微极涡参数对流场和传热的影响。结果表明，与纯纳米流体模型相比，微极性纳米流体模型的传热和传质速率较低。与传统纳米流体相比，混合微极纳米流体在热浮力主导区域显示出更高的传热和传质速率。相反，当将微极混合纳米流体用于溶质主导状态时，传热和传质速率会降低。