Filtration of nano-aerosol using nanofiber filter under low Peclet number and transitional flow regime

► Filtration under low Peclet number (Pe ∼  O(1)) and transitional flow regime (10 > Knf > 0.25). ► New correlation on diffusion in filtration efficiency especially for ultrafine particles, <100 nm. ► Larger efficiency drop at smaller aerosol sizes when filtration velocity increases. ► Smaller fiber diameter yields higher efficiency, also incurs higher pressure drop.