Wang Bo-Fu, Zhou Quan, Sun Chao
Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Institute of Applied Mathematics and Mechanics, School of Mechanics and Engineering Science, Shanghai University, Shanghai 200072, China.
Center for Combustion Energy, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, and Department of Engineering Mechanics at School of Aerospace Engineering, Tsinghua University, Beijing 100084, China.
Sci Adv. 2020 May 22;6(21):eaaz8239. doi: 10.1126/sciadv.aaz8239. eCollection 2020 May.
Thermal turbulence is well known as a potent means to convey heat across space by a moving fluid. The existence of the boundary layers near the plates, however, bottlenecks its heat-exchange capability. Here, we conceptualize a mechanism of thermal vibrational turbulence that breaks through the boundary-layer limitation and achieves massive heat-transport enhancement. When horizontal vibration is applied to the convection cell, a strong shear is induced to the body of fluid near the conducting plates, which destabilizes thermal boundary layers, vigorously triggers the eruptions of thermal plumes, and leads to a heat-transport enhancement by up to 600%. We further reveal that such a vibration-induced shear can very efficiently disrupt the boundary layers. The present findings open a new avenue for research into heat transport and will also bring profound changes in many industrial applications where thermal flux through a fluid is involved and the mechanical vibration is usually inevitable.
热湍流是一种众所周知的通过移动流体在空间中传递热量的有效方式。然而，平板附近边界层的存在限制了其热交换能力。在此，我们提出了一种热振动湍流机制，该机制突破了边界层限制，实现了大量的热传输增强。当对对流单元施加水平振动时，会在导电板附近的流体主体中引起强烈剪切，这会使热边界层失稳，强烈触发热羽流的喷发，并使热传输增强高达600%。我们进一步揭示，这种由振动引起的剪切可以非常有效地破坏边界层。本研究结果为热传输研究开辟了一条新途径，也将给许多涉及流体热通量且通常不可避免存在机械振动的工业应用带来深刻变革。
