Numerical Simulation and Heat Transfer Enhancement of Wavy Microchannels With Secondary Channels

ABSTRACT With the rapid development of electronic devices toward higher performance and miniaturization, the heat flux density increases significantly, which shortens the operational lifespan. Microchannel heat sinks (MCHS), characterized by their high specific surface area, compact structure, and efficient heat transfer, have become an effective solution for dissipating high heat flux. To analyze the thermal–hydraulic performance of MCHS, this study proposes a wavy microchannel with secondary inclined wavy channels (WM‐SIW), which features waveform structures in both the main and secondary channels. The flow and heat transfer characteristics are investigated through numerical simulation over a Reynolds number ( R e) range of 199–995. The performance of WM‐SIW is compared with that of the straight (SM) and rectangular‐ribbed (SMR) microchannel series. The results indicate that among the configurations studied, the dual‐waveform design (WM‐SIW2) achieves the highest overall performance at R e = 995, while the wavy microchannels with secondary inclined straight channels (WM‐SIS) configuration performs better in the approximate range of R e < 900. A parametric analysis of amplitude A , wavelength λ , and secondary channel width ( W t ) further reveals that WM‐SIW3 ( λ = 0.2 mm, A = 0.02 mm, W t = 0.1 mm) exhibits the highest performance evaluation criterion at R e = 995, with a maximum Nusselt number ( N u) of 30.47 and a PEC of 1.803.