Correlation of vorticity structures with heat transfer coefficient and friction factor in corrugated channel geometries.

This thesis investigates the thermo–fluid dynamic behavior of sinusoidal channels, aiming to identify correlations between vorticity structures, pressure losses, and heat transfer performance. Steady-state numerical simulations were performed using OpenFOAM (simpleFoam and scalarTransportFoam) for different corrugation amplitudes and wavelengths, and for a range of Reynolds numbers within the laminar and transitional regimes. The analysis of the vorticity field revealed the formation of recirculation regions and high-shear zones, whose intensity and frequency increase with both wall corrugation and Reynolds number. These flow structures enhance fluid mixing and heat transfer while simultaneously causing higher pressure losses. Mean and maximum vorticity were used as indicators to describe the level of flow disturbance induced by the corrugated geometry. The results demonstrate a clear correlation between the increase in vorticity and the enhancement of the Nusselt number and friction factor, confirming the key role of vortical dynamics in determining the performance of sinusoidal channels. Finally, empirical power-law correlations were developed to quantitatively relate the hydraulic and thermal behavior to the normalized mean vorticity, providing a predictive framework for the design and optimization of compact heat exchangers with corrugated walls.