Študij fokusiranja delcev v mikrofluidnih sistemih z uporabo mrežne Boltzmannove metode

Hubman, Anže (author), Urbič, Tomaž (mentor)

V diplomskem delu je predstavljena obravnava fokusiranja delcev v ravnem mikrofluidnem kanalu. Izvedena je teoretična študija na osnovi mrežne Boltzmannove metode, sklopljene z robnimi pogoji s potopljenimi mejami. V začetku je izvedena validacija numerične metode na primeru fokusiranja enega samega delca in urejanja delcev v homogeni suspenziji. V nadaljevanju so obravnavane heterogene suspenzije z delci dveh različnih velikosti, ki do sedaj teoretično še niso bile obravnavane. Preverjen je vpliv Reynoldsovega števila in razmerja polmerov delcev na tvorbo urejenih struktur. Dodatno je predstavljen vpliv Reynoldsovega števila in velikosti delcev na čas fokusiranja. Demonstrirano je, da obstaja določeno kritično razmerje polmerov delcev, ki prepreči tvorbo stabilnih struktur. Dodatno je ugotovljeno, da na obliko urejenih struktur Reynoldsovo število nima bistvenega vpliva, ima pa vpliv na čas fokusiranja.

• Language: Slovenian
• Keywords: mikrofluidika, mrežna Boltzmannova metoda, fokusiranje delcev
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-128033
• COBISS.SI-ID: 70785283
• Publication date in RUL: 01.07.2021

Secondary language

• Language: English
• Title: Particle focusing in microfluidic systems: A lattice-Boltzmann study

Abstract

In the following thesis we are concerned with particle focusing based on the inertial lift effect in straight microfluidic channels. Extensive numerical simulations based on the lattice Boltzmann method coupled to immersed boundary conditions were performed. We start by first validating the numerical method on simple cases of a single particle focusing and with particle ordering in a homogenous suspension. We continue by applying the validated numerical framework to heterogenous bidisperse suspensions. The influence of the Reynolds number and particle diameter ratio on particle train formation is investigated. The effect of particle size and Reynolds number on focusing time is also discussed. We demonstrate that there exists a critical ratio of radii where a stable particle train cannot be formed. Reynolds number was not found to have a significant effect on the final particle configuration, but did influence the focusing times.

• Keywords: microfluidics, lattice Boltzmann method, particle focusing