Shah Tayyab Raza, Ali Hafiz Muhammad, Janjua Muhammad Mansoor
Mechanical Engineering Department, University of Engineering and Technology, Taxila 47050, Pakistan.
Mechanical Engineering Department, King Fahd University of Petroleum & Minerals (KFUPM), Dhahran 31261, Saudi Arabia.
Nanomaterials (Basel). 2020 Sep 1;10(9):1736. doi: 10.3390/nano10091736.
Although the research on potential use of nanofluids in automotive vehicles is in its embryonic stage, a number of studies have suggested the strong prospect of nanofluids for the efficient thermal management of automotive vehicles. Nevertheless, the pinnacle of nanofluid-based systems awaits stable nanoparticle suspension. The present work studies the heat transfer performance of an aluminum tube automotive radiator with 31 flattened tubes and louvered fins using water and different concentrations (0.04, 0.08, and 0.12 vol.%)-based SiO/water nanofluids as the engine coolant. Inlet temperature and flowrate of the fluid were varied from 60 to 70 °C and 12 to 18 LPM, respectively. The topmost increment in heat transfer rate of 36.92% and Nusselt number of 45.53% were observed in the upper range of tested operational parameters, however, the relative heat transfer increment percentage dropped from 5% (between 0.04 and 0.08 vol.%) to 3.5% (between 0.08 and 0.12 vol.%) due to agglomeration and cluster formation caused by the presence of a greater number of nanoparticles. Precise evaluation of the experimental results was also carried out by reperforming the tests after three days of initial experimentations. A mere deviation of less than 1% was observed between the initial and repeated tests, however, the decline was caused due to the synergistic effects of clustering and fouling.
尽管纳米流体在汽车领域潜在应用的研究尚处于起步阶段，但多项研究表明纳米流体在汽车高效热管理方面具有广阔前景。然而，基于纳米流体的系统的巅峰状态仍有待稳定的纳米颗粒悬浮液的出现。目前的工作研究了一种具有31根扁平管和百叶窗翅片的铝管汽车散热器的传热性能，该散热器使用水和不同浓度（0.04、0.08和0.12体积%）的SiO/水纳米流体作为发动机冷却液。流体的入口温度和流量分别在60至70°C和12至18 LPM之间变化。在测试的运行参数上限范围内，观察到传热速率最高增加了36.92%，努塞尔数最高增加了45.53%，然而，由于大量纳米颗粒的存在导致团聚和团簇形成，相对传热增量百分比从5%（在0.04和0.08体积%之间）降至3.5%（在0.08和0.12体积%之间）。在初始实验三天后重新进行测试，也对实验结果进行了精确评估。初始测试和重复测试之间仅观察到小于1%的偏差，然而，这种下降是由团聚和结垢的协同效应引起的。
