Purpose

The purpose of this study is to present a comprehensive hydrothermal analysis on an inclined mini-channel using numerical and experimental techniques. The fin array acts as heat source within the channel, and a wavy wall located at the top of the channel is heat sink. The side walls are insulated with curved profiles. Also, the channel is inclined with four known inclination angles. To solve the governing equations, the dual-multi-relaxation-time lattice Boltzmann method with D2Q9 and D2Q5 lattice models for flow and temperature fields is used, respectively. Also, the channel is filled with SiO2-glycol nanofluid.

Design/methodology/approach

Identifying the behavior of a thermal component during natural convective flow is a challenging topic due to its complexities. This paper focuses on analyzing the thermal and hydrodynamic aspects of a narrow channel equipping with fin array.

Findings

Two correlations are proposed considering temperature and volume fraction ranges for thermal conductivity and dynamic viscosity according to measured experimental data which are used in the numerical phase. Finally, the structure of flow, temperature distribution of fluid, local thermal and viscous dissipations, volume-averaged entropy production, Bejan number and heat transfer rate are extracted by numerical simulations. The results show that the average Nusselt number enhances about 57% (maximum enhancement percentage) when volume fraction increases from 1% to 3% at Ra = 10⁶ and θ = 90°. In addition, the value of entropy generation is maximum at φ = 1%, Ra = 10⁶ and φ = 90°. Also, the maximum enhancement of entropy generation in range of Ra = 103 to 106 is about 4 times at φ = 1% and θ = 90°.

Originality/value

The originality of the present study is combining a modern numerical method (i.e. dual/multi-relaxation-time LBM) with experimental observation on characteristics of SiO₂-glycol nanofluid to study the thermal and hydrodynamic properties of the studied mini-channel.

中文翻译：

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带鳍片阵列的倾斜微通道的综合水热分析：通过双/多弛豫时间 LBM 和 SiO2-乙二醇流变/热特性实验过程

目的

本研究的目的是使用数值和实验技术对倾斜的微型通道进行全面的热液分析。翅片阵列作为通道内的热源，位于通道顶部的波浪形壁是散热器。侧壁采用弯曲型材隔热。此外，通道以四个已知的倾斜角倾斜。为了求解控制方程，分别使用对流场和温度场的 D2Q9 和 D2Q5 晶格模型的双重多重松弛时间晶格 Boltzmann 方法。此外，该通道充满了 SiO2-乙二醇纳米流体。

设计/方法/方法

由于其复杂性，识别自然对流过程中热组件的行为是一个具有挑战性的话题。本文重点分析配备翅片阵列的窄通道的热力和水动力方面。

发现

根据用于数值阶段的测量实验数据，考虑了温度和体积分数范围，提出了两种相关性，即热导率和动态粘度。最后，通过数值模拟提取了流动结构、流体温度分布、局部热耗散和粘性耗散、体积平均熵产、Bejan数和传热率。结果表明，当体积分数在 Ra = 10 ⁶和θ = 90°时从 1% 增加到 3% 时，平均 Nusselt 数增强了约 57%（最大增强百分比）。此外，熵生成值在φ = 1%、Ra = 10 ⁶和φ 处最大= 90°。此外，在 Ra = 103 到 106 范围内熵生成的最大增强在φ = 1% 和θ = 90° 时约为 4 倍。

原创性/价值

本研究的独创性是将现代数值方法（即双/多弛豫时间 LBM）与对 SiO _{2 -}乙二醇纳米流体特性的实验观察相结合，以研究所研究的微通道的热和流体动力学特性。