Convective heat transfer and thermal dispersion during laminar pulsating flow in porous media

Solid–fluid heat transfer and thermal dispersion during laminar pulsating flow through porous media were numerically studied. Two-dimensional flows in porous media composed of periodically configured arrays of square cylinders were simulated using a computational fluid dynamics tool, with sinusoidal time variation of flow as the inlet boundary condition. Detailed numerical data were obtained for porosities of 0.64–0.84, frequencies of 0–100 Hz, and Reynolds numbers of 70–980, with Reynolds number defined based on the time-average superficial velocity and pore unit-cell dimension. Pore-scale volume-average heat transfer coefficients, and the thermal dispersion term associated with the standard volume-average porous media thermal energy equation were found to be strong functions of porosity, Reynolds number, and most importantly the flow pulsation frequency. Based on the obtained numerical data, empirical correlations were developed for cycle-average pore-scale Nusselt number and the dimensionless thermal dispersion term.