Snap-through oscillations of an elastic sheet for enhanced heat transfer in dual-channel systems

This study explores the use of the snap-through behavior of an elastic sheet as a vortex generator (VG) to enhance heat transfer in a dual-channel system. By leveraging snap-through oscillations, a single sheet clamped at the common wall of the dual channels can simultaneously enhance heat transfer in both channels with a reduced pressure drop. The thermohydraulic performance is analyzed using the immersed boundary-lattice Boltzmann method across varying system parameters. The results demonstrate that for a given Reynolds number (Re), the sheet can operate in either a snap-through mode or dormant mode, depending on its buckled length and bending stiffness (EI*). The snap-through mode achieves superior heat transfer performance, especially at lower bending stiffness, with a thermal efficiency factor (η) of 1.3 at EI* = 0.002, outperforming the wall-clamped flag configuration by 5% and the rigid VG by 14.5%. Comparative analysis reveals that, while the wall-clamped flag configuration is more effective at higher bending stiffness, the proposed VG excels at lower bending stiffness, making these configurations complementary across different applications. The performance of the VG can be further adjusted by modifying the buckled distance of the sheet, with η decreasing as the buckled length increases. Additionally, as Re rises, oscillation-induced flow separation intensifies, further enhancing convective heat transfer. At Re = 1000, η exceeds 1.4, demonstrating robust performance in high-Re regimes. These findings highlight the VG’s potential for tunable and efficient heat transfer enhancement in dual-channel applications.