Evolution of temperature field within porous media subjected to a thermal gradient

The development of geothermal resources gives rise to temperature variations in the surrounding groundwater flow. This study employed numerical simulation methods. The aim was to investigate the distribution of temperature fields at different heights and time intervals within the flowing water, as well as the variations in flow temperature under different influencing factors. The findings of this study revealed that the outflow temperature of the flowing water was influenced by the cold section under the impact of a temperature gradient. As the flow velocity increases, this influence became weaker. In addition, the distance to the warm section was inversely proportional to the time required for the flow temperature to stabilise. The initial temperature had the least impact on the flow temperature, whereas variations in liquid level and particle size affected the flow temperature indirectly through changes in flow velocity. The length of the flow path exerted the greatest influence on the flow temperature field. By custom-defining the rate of temperature change, the influence of the temperature gradient on the flow temperature could be effectively determined. A suitable mathematical expression for the temperature of the outlet water was presented.