Enhancing heat transfer while minimizing pressure drop is a critical challenge in compact heat exchanger design. This review examines oscillatory flow and periodic surface geometries as promising solutions because they play a significant role in disrupting boundary layers, promoting mixing, and enhancing convective performance. Analytical, numerical, and experimental methods for sinusoidal and corrugated channels
under both uniform and non-uniform heat fluxes are systematically reviewed. Most previous reviews have addressed oscillatory or steady flows in smooth or wavy tubes under uniform heat flux, while the combined influence of oscillatory flow, wavy geometry, and time-varying heat flux remains largely unexplored. This review highlights a gap by analysing available studies on hybrid thermal–hydrodynamic interactions from 2005
to 2025. The most significant finding was that periodic geometries can enhance heat transfer by up to four- to fivefold compared with smooth channels. Compared with non-oscillatory flow at the same Reynolds number, the Nusselt number increases by up to 20%. This improvement is primarily due to oscillatory motion, which disrupts the thermal boundary layer and enhances fluid mixing, thereby intensifying convective heat transfer. It can be concluded from these results that a hybrid strategy combining periodic surfaces and oscillatory flow can achieve significant enhancement of heat transfer while maintaining controllable pressure losses. Beyond previous studies that addressed active (oscillation) and passive (geometry) methods independently, this work introduces a new consideration of triple-periodic boundary conditions by integrating the oscillatory flow and the wavy surface under an actual unsteady heat flux. Knowledge gained from this review can be immediately applied to a wide range of real-world systems where effective thermal management is crucial.