In article simulating airborne infection, Wells-Riley model is usually chosed and the "quanta generation rate" can be defined according to other data( e.g. 100/h). However, as far as I understand, the "quanta" is an artificially defined noun rather than specific substance like particle (e.g. 5 μm) which can be directly modeld in CFD. In order to achieve the simulation, I guess that a "quanta" is modeled as a particle (e.g. 5 μm) exhaled from an infector in absence of the dose of a "quanta". If no, how to simulate quanta disperssion in CFD?