Convective thermal rot-amplifiers with Venturi-effect and nonreciprocity characteristics: Rotating and amplifying thermal fluid flows simultaneously

• Published in: International communications in heat and mass transfer 2024-12, Vol.159, p.108063, Article 108063
• Main Authors: Yao, Neng-Zhi, Wang, Hao, Wu, Chen-Long, Wang, Bin, Wang, Xuesheng
• Format: Article
• Language: English
• Subjects: Nonreciprocity; Thermal rot-amplifiers; Transformation heat transfer; Venturi effects
• ISSN: 0735-1933
• DOI: 10.1016/j.icheatmasstransfer.2024.108063

Although thermal metamaterials have garnered considerable attention, the majority of investigations thus far have primarily focused on either steady heat conduction phenomena or steady heat convection systems. However, transient thermally convective flows are prevalent in practical applications. In this study, we employ transformation theory to analytically design convective thermal rot-amplifiers under nonporous-media creeping flows within thermal systems. Through simultaneous manipulation of the effective dynamic viscosity and effective thermal conductivity, we achieve concurrent rotation and amplification of both the dynamic temperature and velocity fields in creeping thermally convective flows. Additionally, convective thermal hysteresis is obtained through dedicated coordinate transformation design, introducing novel thermal regulation mechanisms. Furthermore, the proposed convective thermal rot-amplifiers achieve both hydro-hidden Venturi effect and thermo-hidden Venturi effect, resulting in significantly increased energy harvest efficiencies. We anticipate that the proposed convective thermal rot-amplifiers can be utilized in engineering to vary the orientations of amplified heat fluxes and fluid flows without disturbance, while also shedding light on the hysteresis and nonreciprocity concepts of other meta-devices, and contributing to alleviate the global energy crisis.