Asymmetrical carbon nanotubes exhibit opposing thermal rectification behaviors under different heat baths

Type
Article

Authors
Chen, Wei-Jen
Feng, Biao
Shao, Cheng
Yang, Jin
Fan, Liwu
Ong, Wee-Liat
Chang, I-Ling

Online Publication Date
2021-12-11

Print Publication Date
2022-03

Date
2021-12-11

Abstract
Asymmetrical nanostructures are leading candidates to create efficient thermal rectifiers critical in thermal management and energy conversion systems. Due to their nanoscale size and inherent non-equilibrium nature, their working principles are commonly elucidated through non-equilibrium molecular dynamic simulations. Using asymmetrical carbon nanotubes, the resulting thermal rectification under different heat baths is found to differ in magnitude and direction. We find that nanotubes with the Langevin baths have a higher thermal conductivity in one heat flow direction due to the low-frequency phonons, resulting in a positive rectification. On the other hand, nanotubes with the Nose-Hoover baths show similar thermal conductivity contributions in both heat flow directions across the whole phonon frequency range, culminating in a negative rectification. Our work highlights how asymmetrical carbon nanostructures can rectify heat flow differently under different heat baths and provides strong evidence for the need to consider their non-equilibrium phonon spectrum before analyzing any associated nanoscale thermal transport phenomena.

Citation
Chen, W.-J., Feng, B., Shao, C., Yang, J., Fan, L., Ong, W.-L., & Chang, I.-L. (2022). Asymmetrical carbon nanotubes exhibit opposing thermal rectification behaviors under different heat baths. International Journal of Heat and Mass Transfer, 184, 122341. doi:10.1016/j.ijheatmasstransfer.2021.122341

Acknowledgements
This publication is based upon work supported by the National Natural Science Foundation of China (Grant: 51876186), the Natural Science Foundation of Zhejiang Province (Key Grant: LZ19E060002), and ZJUI with W-L. O. as one of the principal supervisors. W-L. O. acknowledge the support of IDEA SUTD-ZJU Visiting Professor Grant (Project No. ZJUVP2000101). The authors would also like to acknowledge the helpful discussions with Dr. Md Azimul Haque and Dr. Derya Baran at KAUST (Saudi Arabia) and Dr. Yee Sin Ang at SUTD (Singapore) as well as the support from the ZJUI computing facility.

Publisher
Elsevier BV

Journal
International Journal of Heat and Mass Transfer

DOI
10.1016/j.ijheatmasstransfer.2021.122341

Additional Links
https://linkinghub.elsevier.com/retrieve/pii/S001793102101440X

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