IFW Dresden, P. O. Box 270116, 01171 Dresden, Germany.
Samsung Electronics Co., Ltd, Digital Appliance Business R&D team, Samsung-ro 129, 16677 Suwon, Korea.
Sci Rep. 2017 Mar 27;7:45323. doi: 10.1038/srep45323.
Interface-inspired convection is a key heat transfer scheme for hot spot cooling and thermal energy transfer. An unavoidable trade-off of the convective heat transfer is pressure loss caused by fluidic resistance on an interface. To overcome this limitation, we uncover that nano-inspired interfaces can trigger a peculiar fluidic interactivity, which can pursue all the two sides of the coin: heat transfer and fluidic friction. We demonstrate the validity of a quasi-fin effect of Si-based nanostructures based on conductive capability of heat dissipation valid under the interactivity with fluidic viscous sublayer. The exclusive fluid-interface friction is achieved when the height of the nanostructures is much less than the thickness of the viscous sublayers in the turbulent regime. The strategic nanostructures show an enhancement of heat transfer coefficients in the wall jet region by more than 21% without any significant macroscale pressure loss under single-phase impinging jet. Nanostructures guaranteeing fluid access via an equivalent vacancy larger than the diffusive path length of viscid flow lead to local heat transfer enhancement of more than 13% at a stagnation point. Functional nanostructures will give shape to possible breakthroughs in heat transfer and its optimization can be pursued for engineered systems.
界面启发的对流是热点冷却和热能传递的关键传热方案。界面上的流体阻力会导致不可避免的对流换热的权衡取舍,即压力损失。为了克服这一限制,我们发现纳米启发的界面可以引发一种特殊的流固相互作用,这种相互作用可以同时兼顾传热和流体摩擦这两个方面。我们基于散热的导热能力,展示了基于 Si 的纳米结构的准翅片效应的有效性,这种有效性在与流体粘性底层的相互作用下是有效的。当纳米结构的高度远小于湍流中粘性底层的厚度时,就可以实现独特的流体-界面摩擦。在单相冲击射流中,纳米结构在不产生任何显著宏观压力损失的情况下,在壁面射流区域将传热系数提高了 21%以上。纳米结构通过等效的空位来保证流体进入,这个空位大于粘性流动的扩散路径长度,从而导致驻点处的局部传热增强超过 13%。功能化的纳米结构将为传热领域带来可能的突破,其优化可以针对工程系统进行研究。