Purpose

The purpose of this study is to analyze the influence of the main physical–numerical parameters in the computational evaluation of natural convection heat transfer rates in isothermal flat square plates in the laminar regime. Moreover by experimentally validate the results of the numerical models and define the best parameter settings for the problem situation studied.

Design/methodology/approach

The present work is an extension of the study by Verderio Junior et al. (2021), differing in the modeling, results analysis and conclusions for the laminar flow regime with Rade=1×105. The analysis of the influence and precision of the physical–numerical parameters: boundary conditions, degree of mesh refinement, refinement layers and κ – ω SST and κ – ε turbulence models, occurred from the results from 48 numerical models, which were simulated using the OpenFOAM® software. Comparing the experimental mean Nusselt number with the numerical values obtained in the simulations and the analysis of the relative errors were used in the evaluation of the advantages, restrictions and selection of the most adequate parameters to the studied problem situation.

Findings

The numerical results of the simulations were validated, with excellent precision, from the experimental reference by Kitamura et al. (2015). The application of the κ – ω SST and κ – ε turbulence models and the boundary conditions (with and without wall functions) were also physically validated. The use of the κ – ω SST and κ – ε turbulence models, in terms of cost-benefit and precision, proved to be inefficient in the problem situation studied. Simulations without turbulence models proved to be the best option for the physical model for the studies developed. The use of refinement layers, especially in applications with wall functions and turbulence models, proved unfeasible.

Practical implications

Use of the physical–numerical parameters studied and validated, and application of the modeling and analysis methodology developed in projects and optimizations of natural convection thermal systems in a laminar flow regime. Just like, reduce costs and the dependence on the construction of experimental apparatus to obtain experimental results and in the numerical-experimental validation process.

Social implications

Exclusive use of free and open-source computational tools as an alternative to feasible research in the computational fluid dynamics area in conditions of budget constraints and lack of higher value-added infrastructure, with applicability in the academic and industrial areas.

Originality/value

The results and discussions presented are original and new for the applied study of laminar natural convection in isothermal flat plate, with analysis and validation of the main physical and numerical influence parameters.

中文翻译：

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三维方形板上自然对流层流模拟中的物理-数值参数

目的

本研究的目的是分析主要物理-数值参数对层流状态下等温方形板的自然对流换热率的计算评估的影响。此外，通过实验验证数值模型的结果并为所研究的问题情况定义最佳参数设置。

设计/方法/方法

目前的工作是 Verderio Junior等人研究的延伸。(2021)，不同层流状态的建模、结果分析和结论 电阻一种d电子=1×105. 物理-数值参数的影响和精度分析：边界条件、网格细化程度、细化层和κ - ω SST和κ - ε湍流模型，发生在 48 个数值模型的结果中，这些模型使用OpenFOAM® 软件。将实验平均 Nusselt 数与模拟中获得的数值进行比较，并对相对误差进行分析，以评估对所研究问题情况的优势、限制和选择最合适的参数。

发现

从 Kitamura等人的实验参考文献中，以极好的精度验证了模拟的数值结果。(2015)。所述的应用κ - ωSST和κ - ε湍流模型和边界条件（有和没有壁面函数）也物理地验证。使用的κ - ωSST和κ - ε在成本效益和精度方面，湍流模型在所研究的问题情况下被证明是低效的。没有湍流模型的模拟被证明是用于研究开发的物理模型的最佳选择。细化层的使用，特别是在具有壁函数和湍流模型的应用中，被证明是不可行的。

实际影响

使用研究和验证的物理-数值参数，以及在自然对流热系统的项目和优化中开发的建模和分析方法在层流状态下的应用。就像，降低成本和在获得实验结果和数值实验验证过程中对实验装置构建的依赖。

社会影响

在预算限制和缺乏更高附加值的基础设施的情况下，独家使用免费和开源计算工具作为计算流体动力学领域可行研究的替代方案，适用于学术和工业领域。

原创性/价值

所提出的结果和讨论对于等温平板层流自然对流的应用研究是新颖的，并且对主要物理和数值影响参数进行了分析和验证。