Steady-state laminar natural convection of Cu and TiO2 nanofluids inside different enclosures is numerically investigated. Natural convection is concerned due to a temperature difference between the hot and cold surfaces. The Boussinesq approximation is used to form the governing equations and the commercial software package ANSYS FLUENT version 14.0 is used to numerically solve the governing equations. The temperature profiles and flow patterns at different Rayleigh numbers, i.e., 104, 105and 106 are studied and compared for different curved geometries which are 1/8, 2/8 and 3/8 of the height of the enclosure. Heat transfer coefficients are presented for enclosures with different nanofluid concentrations. The nanoparticles enhance the heat transfer. The heat transfer enhancement increases with increasing nanoparticle concentrations. A new curved enclosure is suggested to augment heat transfer. (Less)

中文翻译：

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非常规外壳内 Cu 和 TiO2 纳米流体的自然对流分析

数值研究了不同外壳内 Cu 和 TiO2 纳米流体的稳态层流自然对流。由于热表面和冷表面之间的温差，自然对流受到关注。Boussinesq 近似用于形成控制方程，商业软件包 ANSYS FLUENT 14.0 版用于对控制方程进行数值求解。研究并比较了不同瑞利数（即 104、105 和 106）下的温度分布和流动模式，这些曲线几何形状为外壳高度的 1/8、2/8 和 3/8。给出了具有不同纳米流体浓度的外壳的传热系数。纳米颗粒增强了热传递。传热增强随着纳米颗粒浓度的增加而增加。建议使用新的弯曲外壳来增强热传递。（较少的）