Bionics provides innovative inspiration for the design of heat exchange equipment. Although the excellent flow control and heat transfer characteristics of shark skin, arising from its unique micro-rib structures, have been widely recognized, their application in shell-and-tube heat exchangers remains insufficiently understood. In this study, a shark skin-inspired microstructured heat exchange tube was proposed, and the influence of the bio-inspired surface on coherent structure evolution and heat transfer in the shell-side flow domain of a tube bundle was investigated. A high-fidelity numerical framework combining Reynolds Averaged Navier Stokes (RANS) pre-calculation and Large Eddy Simulation (LES) was proposed; by utilizing the RANS-predicted Taylor microscale to guide mesh generation and the Minimal Flow Unit theory for turbulence initialization, this method achieved a turbulent kinetic energy resolution rate exceeding 99% in a single iteration, significantly reducing computational costs. In addition, the field synergy principle was introduced to analyze the coupled transport mechanism of momentum and heat. The results show that the diamond-shaped discontinuous micro-rib arrangement plays a dominant role in regulating near-wall vortex evolution and heat transfer, whereas the influence of specific rib morphology is comparatively limited. The rhombic arrangement promotes the formation of inter-rib vortex clusters and the lifting of streamwise vortices, thereby enhancing the synergistic transport of momentum and heat. At Re = 10000, the local peak Nusselt number increased by nearly six times compared to the smooth wall, and the near-wall peak vorticity magnitude and temperature-gradient magnitude increased by approximately 20%. This enhancement mechanism remains effective at Re = 60000. A high spatial correlation between the distributions of | ∇ × U | and | ∇ T | further confirms that heat transfer enhancement is coupled with intensified momentum transport. These findings provide high-fidelity physical insight into the thermal enhancement mechanism of shark skin-inspired surfaces and establish a mechanistic basis for the engineering design of biomimetic heat-transfer tubes. • The bio-inspired shark skin microstructure with a rhombic staggered rib. • The high-precision LES with low computational cost, achieving over 99% resolved turbulent kinetic energy, is based on the minimum flow unit theory and sinusoidal velocity streaks. • Synergistic momentum-thermal transport mechanism driven by vortex dynamics.
Sun et al. (Wed,) studied this question.