Tesla valves and capillary structures-activated thermal regulator

• Published in: Nature communications Vol. 14; no. 1; p. 3996
• Main Authors: Li, Wenming, Yang, Siyan, Chen, Yongping, Li, Chen, Wang, Zuankai
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06-07-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 639/166; 639/166/898; 639/301/1005/190; 639/766/189; 639/766/25; Confined spaces; Electronic equipment; Flow distribution; Flow pattern; Heat flux; Heat transfer; Heat transfer coefficients; Humanities and Social Sciences; Latent heat; Liquid flow; multidisciplinary; Multiphase flow; Phase transitions; Science; Science (multidisciplinary); Size effects; Specific volume; Thermal management; Two phase flow; Valves; Vapor phases; Vapors; Working conditions
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-39289-5

Two-phase (liquid, vapor) flow in confined spaces is fundamentally interesting and practically important in many practical applications such as thermal management, offering the potential to impart high thermal transport performance owing to high surface-to-volume ratio and latent heat released during liquid/vapor phase transition. However, the associated physical size effect, in coupling with the striking contrast in specific volume between liquid and vapor phases, also leads to the onset of unwanted vapor backflow and chaotic two-phase flow patterns, which seriously deteriorates the practical thermal transport performances. Here, we develop a thermal regulator consisting of classical Tesla valves and engineered capillary structures, which can switch its working states and boost its heat transfer coefficient and critical heat flux in its “switched-on” state. We demonstrate that the Tesla valves and the capillary structures serve to eliminate vapor backflow and promote liquid flow along the sidewalls of both Tesla valves and main channels, respectively, which synergistically enable the thermal regulator to self-adapt to varying working conditions by rectifying the chaotic two-phase flow into an ordered and directional flow. We envision that revisiting century-old design can promote the development of next generation cooling devices towards switchable and very high heat transfer performances for power electronic devices.
Unwanted vapor backflow and chaotic two-phase flow patterns can hinder thermal transport performance in their respective systems. Here, the authors revisit the classic Tesla valve design and demonstrate a Tesla valve-based thermal regulator with capillary structures that can suppress vapor backflow and achieve directional two-phase flow.