Numerical study of turbulent heat transfer in 3D pin-fin channels: Validation of a quick procedure to estimate mean values in quasi-periodic flows

Pin-fin heat exchangers are widely used and there is an increasing interest in the design of compact units. This work investigated the prediction of the heat transfer rate in pin-fin channel flows using numerical simulation, considering pins of cylindrical geometry in aligned and staggered arrangements. The simulations were performed using the Reynolds-averaged Navier–Stokes equations together with the shear stress transport turbulence model. The main purpose of this work was to develop and validate a quick numerical procedure to evaluate the heat transfer rate in pin-fin channel flows using their quasi-steady behavior. The procedure was validated by comparing the mean Nusselt number results with time-averaged Nusselt numbers obtained from transient simulations. It was also shown that these values are in good agreement with available experimental data. This procedure could determine the overall mean Nusselt number up to 25 times faster. The importance of the quasi-steady flow behavior on the heat transfer was also quantified.