Abstract The discrete heating strategy has been identified as an energy efficient method. The current work is aimed at achieving a thermally efficient triangular-design 1 (regular isosceles triangle), triangular-design 2 (inverted isosceles triangle) and square enclosures based on the entropy generation studies involving strategic positioning of the double heaters along each side wall (case 1: larger heater in lower half and smaller heater in central half, case 2: larger heater in central half and smaller heater in lower half, case 3: two heaters of identical lengths located at central and lower halves) for Pr = 0.015 and 7.2 involving Ra = 10 3 – 10 5 . The numerical results of the cases 1–3 have been further compared with the case involving single heater along each side wall (case 0). Galerkin finite element method is implemented for the accurate evaluation of the entropy generation terms based on elemental basis set. Cases 1–3 exhibit lower entropy generation and higher heat transfer rates in the convection dominant regime ( Ra = 10 5 ) compared to the case 0. Overall, case 3 is concluded to be optimal based on higher rate of heat transfer and lower entropy generation.

中文翻译：

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多个离散加热器在充满流体的方形和三角形外壳中自然对流过程中最小化熵产生的作用

摘要 离散加热策略已被确定为一种节能方法。当前的工作旨在基于熵产生研究实现热效率三角形设计 1（规则等腰三角形）、三角形设计 2（倒等腰三角形）和方形外壳，这些研究涉及沿每个侧壁战略定位双加热器（案例 1：下半部较大的加热器和中部较小的加热器，案例 2：中部较大的加热器和下半部较小的加热器，案例 3：位于中部和下半部的两个相同长度的加热器）对于 Pr = 0.015 和7.2 涉及 Ra = 10 3 – 10 5 。案例 1-3 的数值结果已与沿每个侧壁涉及单个加热器的案例（案例 0）进行了进一步的比较。使用伽辽金有限元方法，基于元素基组对熵生成项进行准确评估。与案例 0 相比，案例 1-3 在对流主导区域 (Ra = 10 5 ) 表现出较低的熵产生和较高的传热速率。总体而言，基于较高的传热速率和较低的熵产生，案例 3 被认为是最佳的.