Confl’uence Chao Sun – Professor at the Center for Combustion Energy, the Department of Energy and Power Engineering, and the School of Aerospace Engineering at Tsinghua University.
Mercredi 20 novembre à 10 h 30 Amphithéâtre Nougaro
Turbulence is known for its ability to vigorously mix fluid and transport heat. While over a century of research effort has been devoted to heat transport enhancement, few have exceeded the inherent limits posed by turbulent-mixing. Here we have conceptualized an “active particle” turbulence machine: we find that by adding a minute concentration (~1\%) of a heavy liquid (hydrofluoroether) to a water-based turbulent convection system, remarkably, highly efficient biphasic dynamics is born, which supersedes turbulent heat transport by up to 500%. The system is unique in that it operates on a self-sustained dynamically equilibrated cycle of a “catalyst-like” species, and exploits several heat-carrier agents including pseudo-turbulence, latent heat and bidirectional wake capture. We find that the heat transfer enhancement is dominated by the kinematics of the active elements and their induced-agitation. The present finding opens the door towards the establishment of tunable, ultra-high efficiency heat transfer/mixing systems.