In this presentation, flow physics and natural heat transfer of water/Ag nanofluid are implemented by utilizing finite volume method (FVM) considering 0–6% of solid nanoparticles in volume fraction in an elliptical-shaped enclosure affected by different attack angles range from 45° to 135°. This survey's foremost objective is to find the optimum attack angle for the highest heat transfer performance in the studied geometry. The attained results demonstrated that the Rayleigh number's augmentation leads to buoyancy force amplification and intensification of velocity components in the enclosure. Hence, the shapes of streamlines for each attack angle are different from the other states. The enhancement of the Rayleigh number causes better temperature distribution between cold and hot sources. The attack angle changes are the other factor for creating and intensity of the temperature gradients. By increasing the attack angle when the heat is transferred from the hot source to the top of the enclosure, the thermal distribution effects come with high gradients due to the flow balance disturbance and the changes in two sources' location. As the fluid moves, velocity components always change. In Rayleigh number of Ra = 1 × 10³ due to a decrease of buoyancy force and negligible density changes in the enclosure, the average friction coefficient (C_fave) is not considerable, and for everyone studied attack angles, these changes are negligible. By augmenting attack angle (attack angles of 90° and 135°), because the tangential velocity component is weakened by gravity force, the values of created surface stress and fluid adhesion to the hot surface are less.

中文翻译：

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不同攻角椭圆外壳内水/银纳米流体的自然对流换热

在本演示文稿中，水/Ag 纳米流体的流动物理和自然传热是通过利用有限体积法 (FVM) 实现的，考虑到椭圆形外壳中体积分数为 0-6% 的固体纳米颗粒，受不同攻角的影响范围为 45 ° 至 135°。这项调查的首要目标是在所研究的几何形状中找到最佳热传递性能的最佳攻角。获得的结果表明，瑞利数的增加导致浮力放大和外壳中速度分量的增强。因此，每个攻角的流线形状都不同于其他状态。瑞利数的增强导致冷源和热源之间的温度分布更好。攻角变化是产生温度梯度和强度的另一个因素。当热量从热源转移到外壳顶部时，通过增加攻角，由于流动平衡扰动和两个热源位置的变化，热分布效应具有高梯度。随着流体的移动，速度分量总是会发生变化。在瑞利数 Ra = 1 × 10³由于浮力的减少和外壳中可忽略的密度变化，平均摩擦系数（C _fave）并不可观，对于每个研究过的攻角来说，这些变化都可以忽略不计。通过增大攻角（攻角分别为 90° 和 135°），由于切向速度分量被重力减弱，产生的表面应力和流体对热表面的粘附值较小。