Experimental Validation of Non-Fourier Thermal Response in Porous Media

An experimental validation of non-Fourier behavior in porous media due to short time thermal perturbation is presented. The governing energy equation is formulated based on the two-equation model and the non-Fourier model. This formulation leads to the emergence of four thermal parameters: lag-time in heat flux τq, lag-time τt in temperature due to interstitial heat transfer coefficient h, and lag-time in the transient response of the temperature gradient τx in the heat flux equation. These parameters account for the microstructural thermal interaction between the fluid and neighboring solid matrix as well as the delay time needed for both phases to approach thermal equilibrium. An experimental verification of the microscale model was performed under standard laboratory conditions. The values of the aforementioned thermal parameters were determined to compute the fluid and solid temperatures. Results predicted from three models (classical Fourier, non-Fourier, and experimental) were compared. It indicates an excellent agreement between the non-Fourier and the experimental model, and a significant deviation of Fourier prediction from the experimental results.