2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/163776I propose an extension to Boltzmann BGK equation for Hard Spheres. The present model has an $H$-theorem and it allows choice of Prandtl number as an independent parameter. I show that similar to Enskog equation this equation can reproduce dynamics of hard spheres in dense systems.Statistical MechanicsSoft Condensed Mattertext