In the thesis, we analyzed hydrodynamic and thermal phenomena in microchannel heat exchangers under laminar water flow (Re = 1000) and constant heat flux (q = 40000 W⋅m$^{-2}$). The goal was to find the type of geometry that most optimally dissipated thermal energy. Three different types of channel geometry were analyzed: straight reference square microchannel, curved square sinusoidal microchannel with various amplitudes and wave lengths, and wide microchannels with expansion.
The research showed that sinusoidal microchannels greatly enhanced heat dissipation due to the formation of Dean vortices in curved parts, which contribute to fluid mixing. The most optimal sinusoidal geometry (A = 2 mm, λ = 18 mm) almost tripled the value of average heat transfer coefficient and lowered the average temperature of the upper copper plate by 13 °C with respect to the straight channel. Wide microchannels proved to be less efficient due to lower fluid velocities.
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