@Article{fhmt.2026.088763,
AUTHOR = {Tomoya Kazumi, Kota Fujisawa, Kenta Emori, Takashi Fukue, Yasuhiro Sugimoto},
TITLE = {Basic Study on Heat Transfer Enhancement in Straight Fins by Pulsating Flow},
JOURNAL = {Frontiers in Heat and Mass Transfer},
VOLUME = {},
YEAR = {},
NUMBER = {},
PAGES = {{pages}},
URL = {http://www.techscience.com/fhmt/online/detail/28264},
ISSN = {2151-8629},
ABSTRACT = {Efficient thermal management is essential for high-heat-flux electronic devices, where increasing power density and compact packaging impose strict requirements on cooling performance with minimal pressure drop. Pulsating flow has been proposed as a technique to enhance heat transfer; however, its effects on practical heat sink geometries remain insufficiently understood. This study investigates the thermal-hydraulic characteristics of pulsating flow in a multi-straight-fin heat sink operating in the laminar and transitional flow regimes (<i>Re</i> = 480–2400) through a combination of heat transfer experiments and three-dimensional Computational Fluid Dynamics (CFD) analyses. The effects of pulsation frequency, amplitude, and Reynolds number on heat-transfer and pressure-drop characteristics were evaluated using the mean Stanton number, friction coefficient, and performance evaluation criteria (PEC). The CFD model was validated against experimental measurements and used to analyze phase-resolved velocity and temperature fields. The results showed that pulsating flow can either enhance or deteriorate thermal performance depending on the pulsation conditions. Higher pulsation frequencies improved both the mean Stanton number and PEC, whereas lower frequencies reduced overall performance. The enhancement was most pronounced at an intermediate Reynolds number of approximately Re = 960. Increasing pulsation amplitude increased both heat transfer and pressure drop, resulting in little variation in PEC. Local heat-transfer evaluations demonstrated that the enhancement effect became more significant in the downstream region. CFD analyses revealed that periodic disturbances of the thermal boundary layer caused by unsteady near-wall flow were responsible for the enhanced heat transfer. These findings provide fundamental insights into the thermal-hydraulic characteristics and enhancement mechanisms of pulsating flow and support its application to compact liquid-cooled heat sinks for high-heat-flux electronic devices.},
DOI = {10.32604/fhmt.2026.088763}
}