Dilute gas-particle suspension in a diffuser: A two-fluid modelling approach

The present study evaluates the loss coefficient of a diffuser carrying a gas–solid mixture with the volume fraction of the solid in the medium to upper limits of the dilute phase flow (solid volume fraction in the range of 0.005–0.10). In light of the computational analysis, it is observed that an increase in the concentration of the solid phase always helps in overcoming the losses despite a significant dissipation of energy due to collisions. Moreover, the loss coefficient lessens as the solid-phase density reduces. Under the operating conditions where the collisions become significant, a critical particle size (≈200 μm) is obtained. The loss coefficient mitigates gradually with an increase in the particle size up to this value but enhances beyond it. An increase in the diffuser angle enhances the loss; however, its effect becomes less prominent as the solid volume fraction increases (typically for solid volume fraction greater than or equal to 0.02).