In this paper, a three-dimensional analysis is used to study the heat transfer and fluid flow characteristics in ducts with various cross-sectional areas using GO + Co₃O₄/water (H₂O) hybrid nanofluids. Four types of geometries (flat, elliptical and circular ducts) with the same hydraulic diameter were investigated. All simulations were performed for inlet velocities within the range 0.043–0.347 m s⁻¹. The heat transfer, pressure drop, dimensionless entropy generation and modified dimensionless entropy generation were investigated considering the nanoparticle volume concentrations between 0.10 and 0.20%. The results indicate that the flat duct has higher heat transfer coefficients up to 44% than the circular duct. Additionally, the circular duct has 20% lower pressure drop compared to the flat duct. For the flat duct, the maximum reduction in modified dimensionless entropy generation was 39.59% compared to the circular duct for a concentration of 0.2% GO + Co₃O₄ hybrid nanoparticles. Finally, the performance evaluation criteria were computed and comparative analysis for all studied geometries was performed. Results indicated that the type of geometry has a significant effect on the heat transfer and fluid flow characteristics in ducts than the concentration of hybrid nanoparticles.

中文翻译：

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不同横截面层流中混合纳米流体行为的数值方法

在本文中，使用GO + Co ₃ O ₄ /水（H ₂ O）杂化纳米流体，对三维横截面进行了三维分析，以研究管道中不同横截面的传热和流体流动特性。研究了四种具有相同水力直径的几何形状（扁平，椭圆形和圆形风管）。对进口速度在0.043–0.347 m s ^-1范围内进行了所有模拟。考虑到纳米粒子体积浓度在0.10％至0.20％之间，研究了传热，压降，无量纲熵产生和改进的无量纲熵产生。结果表明，扁平管道比圆形管道具有更高的传热系数，最高可达44％。此外，圆形导管的压力降比扁平导管低20％。对于扁平风管，与浓度为0.2％GO + Co ₃ O ₄的圆形风管相比，改进的无量纲熵产生的最大减少为39.59％杂化纳米粒子。最后，计算了性能评估标准，并对所有研究的几何形状进行了比较分析。结果表明，几何类型对管道中的传热和流体流动特性的影响比混合纳米颗粒的浓度大。