Zeitoun Obida, Ali Mohamed
King Saud University, Mechanical Engineering Department, King Abdullah Institute for Nanotechnology, 800 Riyadh, 11421, Saudi Arabia.
Nanoscale Res Lett. 2012 Feb 17;7(1):139. doi: 10.1186/1556-276X-7-139.
Experimental investigation to study the heat transfer between a vertical round alumina-water nanofluid jet and a horizontal circular round surface is carried out. Different jet flow rates, jet nozzle diameters, various circular disk diameters and three nanoparticles concentrations (0, 6.6 and 10%, respectively) are used. The experimental results indicate that using nanofluid as a heat transfer carrier can enhance the heat transfer process. For the same Reynolds number, the experimental data show an increase in the Nusselt numbers as the nanoparticle concentration increases. Size of heating disk diameters shows reverse effect on heat transfer. It is also found that presenting the data in terms of Reynolds number at impingement jet diameter can take into account on both effects of jet heights and nozzle diameter. Presenting the data in terms of Peclet numbers, at fixed impingement nozzle diameter, makes the data less sensitive to the percentage change of the nanoparticle concentrations. Finally, general heat transfer correlation is obtained verses Peclet numbers using nanoparticle concentrations and the nozzle diameter ratio as parameters.
开展了一项实验研究，以探究垂直圆形氧化铝 - 水纳米流体射流与水平圆形表面之间的传热情况。使用了不同的射流流速、射流喷嘴直径、各种圆盘直径以及三种纳米颗粒浓度（分别为0%、6.6%和10%）。实验结果表明，使用纳米流体作为传热载体可以增强传热过程。对于相同的雷诺数，实验数据显示随着纳米颗粒浓度的增加，努塞尔数增大。加热盘直径大小对传热呈现相反的影响。还发现，以撞击射流直径处的雷诺数来呈现数据，可以兼顾射流高度和喷嘴直径的影响。在固定撞击喷嘴直径的情况下，以佩克莱数来呈现数据，会使数据对纳米颗粒浓度百分比变化的敏感度降低。最后，以纳米颗粒浓度和喷嘴直径比为参数，得到了与佩克莱数相关的通用传热关联式。
