Optimization for dense location and geometrical parameter of wavy microchannel to improve temperature distribution

In this article, a new locally denser sinusoidal wavy microchannel is proposed to improve the uniformity of temperature distribution. The influence of dense location and geometrical parameters, that is, wavelength (λ3 = 600–1600 μm) and amplitude (A3 = 40–200 μm), waviness factor γ (0.04–0.2) are studied by numerical simulation. Results show, compared with rectangular microchannels, dense wavy microchannels can effectively enhance heat transfer with a larger pressure drop penalty of 53.5–152.6%, but only 29.6–79.9% of locally denser wavy microchannels. Besides, it’s found that dense location influences severe heat transfer performance, but less for pressure drops. Heat transfer performance of downstream dense wavy microchannel is best, and the maximum temperature is reduced by 23 K under Re = 348. But the upstream dense type increases the maximum temperature difference than wave microchannel. Under the same pumping power, the thermal resistance of downstream dense wavy microchannel is reduced by 46% and 20% than straight microchannel and wavy microchannels. Decreasing wavelength and increasing wave amplitude could enhance heat transfer, and the effects become weaker. But the pressure drop is significantly increased. The best overall thermal performance is found for downstream dense wavy microchannel with γ = 0.12 of A3 = 120 μm and λ3 = 1000 μm, in which thermal resistance is reduced 48.6% under same pumping power.