Modeling of Porosity Equation for Water Flow Through Packed Bed of Monosize Spherical Packing. J. eng. sustain. dev. 2011;15(4):205-226. تاريخ الوصول مايو 19, 2024. https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1320