EXPERIMENTAL AND CFD- SIMULATION OF POLLUTANT TRANSPORT IN POROUS MEDIA

Abstract

Efforts were made in this search to design a physical and computer model using the CFD techniques to simulate the problem of transporting pollutants through a porous media in unsteady state case. A physical model was built to measure the transmission of a copper nitrate pollutant at an initial concentration of 25 mg/l in a medium consists of (sand + gravel) and study the movement of the pollutant through. Then the results of the pollutant transport through used in the physical model were entered as entry data to the CFD simulated model using COMSOL 5.4. Software. The results of the CFD simulated model showed that the change in the inlet velocity to more than 20% of the initial velocity increases the pollutant concentration and reduces the time wanted to reach the highest value of the pollutant, while reducing the inlet velocity to less than 20% of the initial velocity, cause to decrease the concentration and increase the time to reach the highest pollutant value. When changing the porosity by (30%, -15%) of the initial porosity, it was noticed that increasing the porosity value reduces the pollutant concentration and increases the time required to reach the highest value of the pollutant. while when the porosity decreases to 15% of the initial porosity, the concentration increases the time decreases to reach the highest value of the pollutant at all control points. The adsorption factor has a noticeable effect on the emergence of the pollutant, while the temperature change was almost imperceptible for all degrees. However, the results of laboratory work were compared with the results of the CFD simulated model, which showed a good match between them.