Poster Presentations
|
Hydrodynamic dispersion in patterned microchannel
Aadithya Kannan, Undergraduate, Indian Institute of Technology Kharagpur
During the chromatographic separation of biological molecules, the resolution gets affected unfavourably due to Taylor dispersion. This work presents the effect of axial flow variation on the hydrodynamic (Taylor-Aris) dispersion in a patterned microchannel, represented by periodic crests and troughs. Under Cassie- Baxter state of wetting, similar to what is observed on a lotus leaf, the flow features are characterized by a developing plug over the trough due to free slip at the air/ liquid interface and developing boundary layer at the crest zones due to no slip at the solid walls. Numerical solutions of the governing equations reveal a narrower solute concentration distribution for Cassie flow compared to flow in smooth channels. Analysis using Aris method of moments shows approximately similar dispersion coefficient, but with a characteristic time lag in the axial dispersion of the solute pulse. The time lag is attributed to a faster transverse stabilization facilitated by plug flow in the trough regions. The improvement of resolution by modifying the channel geometry may have profound applications in microfluidics.
|
|
