方形外壳中离散加热对银、铜和MWCNT纳米流体热性能的影响：CFD分析

IF 3.9 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Vacuum Pub Date : 2025-08-21 DOI:10.1016/j.vacuum.2025.114690

Sudhakar Uppada , G. Jamuna Rani , Yarrapragada Kss Rao , Ravikiran Balaga

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引用次数: 0

摘要

本研究探讨了在纳米流体填充的外壳中，瑞利数（103-106）、纳米颗粒浓度（0.1 vol%-0,5 vol%）和加热位置之间的复杂相互作用，以提高传热效率并最大限度地减少不可逆。以含银（Ag）、铜（Cu）和多壁碳纳米管（MWCNTs）的水基纳米流体为研究对象，建立了一个经过验证的数值模型，分析了这些变量对传热特性和熵生成的影响。结果表明，随着瑞利数的增加，特别是在较高的纳米颗粒浓度下，传热从传导转变为对流为主。在Ld = 0.4和0.5 vol% Ag纳米流体条件下进行离散加热，确定了浮力驱动循环和努塞尔数的最佳条件，从而提高了传热性能，减少了能量损失。研究结果有助于设计先进的被动冷却系统，提高高性能热应用的效率和寿命。

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Impact of discrete heating on thermal performance of Ag, Cu, and MWCNT nanofluids in square enclosure: A CFD analysis

This study investigates the complex interactions between Rayleigh number (10³-10⁶), nanoparticle concentration (0.1 vol%-0,5 vol%), and heating location in nanofluid-filled enclosures to enhance heat transfer efficiency and minimize irreversibilities. Focusing on water-based nanofluids containing silver (Ag), copper (Cu), and multi-walled carbon nanotubes (MWCNTs), a validated numerical model analyzes the impact of these variables on heat transfer characteristics and entropy generation. Results reveal a shift from conduction to convection-dominated heat transfer with increasing Rayleigh numbers, particularly at higher nanoparticle concentrations. Optimal conditions for buoyancy-driven circulation and Nusselt number are identified with discrete heating at L_d = 0.4 and 0.5 vol% Ag nanofluid, leading to improved heat transfer performance and reduced energy losses. The findings contribute to the design of advanced passive cooling systems, enhancing the efficiency and longevity of high-performance thermal applications.

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来源期刊

Vacuum 工程技术-材料科学：综合

CiteScore

6.80

自引率

17.50%

发文量

审稿时长

34 days

期刊介绍： Vacuum is an international rapid publications journal with a focus on short communication. All papers are peer-reviewed, with the review process for short communication geared towards very fast turnaround times. The journal also published full research papers, thematic issues and selected papers from leading conferences. A report in Vacuum should represent a major advance in an area that involves a controlled environment at pressures of one atmosphere or below. The scope of the journal includes: 1. Vacuum; original developments in vacuum pumping and instrumentation, vacuum measurement, vacuum gas dynamics, gas-surface interactions, surface treatment for UHV applications and low outgassing, vacuum melting, sintering, and vacuum metrology. Technology and solutions for large-scale facilities (e.g., particle accelerators and fusion devices). New instrumentation ( e.g., detectors and electron microscopes). 2. Plasma science; advances in PVD, CVD, plasma-assisted CVD, ion sources, deposition processes and analysis. 3. Surface science; surface engineering, surface chemistry, surface analysis, crystal growth, ion-surface interactions and etching, nanometer-scale processing, surface modification. 4. Materials science; novel functional or structural materials. Metals, ceramics, and polymers. Experiments, simulations, and modelling for understanding structure-property relationships. Thin films and coatings. Nanostructures and ion implantation.