Flat plate pulsating heat pipes: A review on the thermohydraulic principles, thermal performances and open issues

• Published in: Applied thermal engineering 2021-10, Vol.197, p.117200, Article 117200
• Main Authors: Ayel, Vincent, Slobodeniuk, Maksym, Bertossi, Rémi, Romestant, Cyril, Bertin, Yves
• Format: Article
• Language: English
• Subjects: Annular flow; Channels; Convection cooling; Diameters; Electronic systems; Electronics; Engineering Sciences; Engraving; Evaporation; Evaporators; Experimental; Flat Plate Pulsating Heat Pipes; Flat plates; Heat conductivity; Heat exchangers; Heat flux; Heat generation; Heat pipes; Heat transfer; Heat transfer performances; Horizontal orientation; Manufacturing; Metal plates; Miniaturization; Parameters; Serpentine; Slug flow; Space applications; System reliability; Technology assessment; Thermal energy; Thermal management
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2021.117200

[Display omitted] •This review focuses on flat plate pulsating heat pipes (FPPHPs).•FPPHPs can be defined by a capillary serpentine channel machined in a solid plate.•Capillary flows in channels with corners modify the operating behaviour of FPPHPs.•Thermal and hydraulic experimental observations of FPPHPs are mainly summarized.•Main application fields of FPPHPs and processes of manufacturing are presented. Thermal management of modern micro- and high-power electronic systems has become a progressively challenging problem due to current trends in miniaturization and increased heat generation. Conventional cooling methods, such as natural and force convection, have become insufficient to meet new challenges in electronics industries, transport and space applications where thermal management system size, mass, autonomy, high density and overall system reliability play a crucial role. Unlike active technologies, heat pipes are passive heat transfer devices without moving mechanisms which lead to greater reliability, even though they are limited by capillary, viscous and/or gravity factors. In contrast, the Pulsating Heat Pipe (also called Oscillating Heat Pipe) has recently become a source of increasing interest: first, due to fascination for the complexity of the internal two-phase phenomena; and secondly, due to novel applications, which are rapidly increasing the Technology Readiness Level of this device, for both ground and space environments. Pulsating heat pipe manufacturing can be divided into two categories: the classical tubular pulsating heat pipe, and the flat plate pulsating heat pipe. While the former is manufactured and developed from a single tube enrolled like a serpentine around heat and cold sources, the latter is obtained from a metallic plate including an engraved serpentine single channel, and hermetically closed on its top side by a second plate. These two manufacturing concepts lead to differences in operating behavior that are worth noting in order to better understand the functioning of the devices. This paper presents a review of recent scientific experimental studies on thermal and flow behaviors of flat plate pulsating heat pipes, which present particular interest due to their structural dissimilarity compared to classical tubular pipes, leading to different thermo-hydrodynamic behaviors. The dissimilarities can be largely explained by the square or rectangular channels, leading to capillary pumping in the corners, and to the therm