Mixed convection of alumina-water nanofluid inside a concentric annulus considering nanoparticle migration

- Mixed convection of alumina-water nanofluid inside a vertical annulus was investigated.
- Modified two-component heterogeneous model for the nanofluid was used.
- Asymmetric heating at the walls changes the direction of nanoparticle migration.
- The efficacy of using nanofluids is always reduced for heat flux ratio ɛ > 1.
- Using smaller nanoparticles enhances the efficacy of using nanofluids.