Using the S-Gamma Model in the Simulation
The S-Gamma model was developed to model the size distribution of dispersed bubbles with the consideration of breakup and coalescence effects.
In dispersed two-phase flows, the strength of interphase forces, and the quantity of heat and mass transfer, are functions of the bubble size. Bubble sizes can change continuously due to coalescence and breakup, therefore being able to account for this size distribution leads to an improved prediction of these quantities. In Simcenter STAR-CCM+, the S-Gamma method of moments has been implemented to account for particle size distributions in dispersed two-phase flows.
- For breakup, the S-Gamma model considers the balance between disruptive forces (due to shear and turbulence) and restoring forces (due to surface tension) on the droplet.
- For coalescence, the S-Gamma model considers the probability of collisions of the droplets, the contact time of two colliding drops, and the drainage time of the liquid film between the drops.