Natural convection in a parallelogrammic enclosure filled with different types of nanofluids (Al₂O₃, Ag and TiO₂) subjected to three discrete heated isoflux is examined numerically by using a heatlines visualization method. The position of three discrete isoflux are at left and right sidewalls remark by (λ = 0.25), while the third isoflux at a bottom wall remark by (ζ = 0.5). The top wall with the remaining regions in the bottom wall is insulated, while the remaining regions in the side walls are maintained at low temperatures. Finite element method based on a Chorin's algorithm used to solve the governing equation continuity, momentum and energy. Numerical calculations were achieved for a wide range of Rayleigh numbers (10⁴≤Ra≤10⁷), skew angle (−30^o≤γ≤+30^o), and volume fraction of nanoparticles (0≤$\mathrm{\Phi }$≤0.2). The result is explained in term of stream functions, isotherms, heatfunctions, local and average Nusselt numbers. It is found that the heat transfer performance considerably improve with the supplement water of various species of nanofluid and changing skew angle. Furthermore, nine correlations are established to approximate the average Nusselt number.

中文翻译：

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在存在离散等通量源的情况下限制在平行四边形腔内的纳米流体的自然对流热传递的热线可视化

平行四边形外壳中的自然对流填充有不同类型的纳米流体（Al ₂ O ₃、Ag 和 TiO ₂），经受三个离散的加热等通量，通过使用热线可视化方法进行数值检查。三个离散等通量的位置在左侧和右侧壁上记为（λ = 0.25），而在底壁处的第三个等通量子记为（ζ = 0.5）。顶壁和底壁中的其余区域是隔热的，而侧壁中的其余区域保持在低温。基于 Chorin 算法的有限元方法，用于求解控制方程的连续性、动量和能量。对大范围的瑞利数 (10 ⁴ ≤Ra≤10⁷ )、倾斜角 (-30 ^o ≤γ≤+30 ^o ) 和纳米粒子的体积分数 (0≤$\mathrm{\Phi }$≤0.2)。结果用流函数、等温线、热函数、局部和平均努塞尔数来解释。结果表明，随着各种纳米流体的补水和倾斜角的改变，传热性能显着提高。此外，建立了九个相关性来近似平均努塞尔数。