Simulating Flow over Nanoparticles through Microchannels Using Lattice Boltzmann Method

Setayeshgar, Alireza | 2009

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 39306 (45)
  4. University: Sharif University of Technology
  5. Department: Aerospace Engineering
  6. Advisor(s): Darbandi, Masoud
  7. Abstract:
  8. Novel manufacturing technologies in micro scales, such as micro machining, guide us through constructing micro scale systems known as MEMS. These systems have a wide range of applications, from fabrication of electrostatic, magnetic, pneumatic sensors and actuators to micro mechanical gears and motors. Also, MEMS applications involve the manipulation of one or more fluids, known as microfluids. Simulation of flow through microchannels over nano particles has important applications in solid particles transport. In this flow, the rarefaction phenomenon will affect the flow behavior and its subsequent impacts such as aerodynamic drag forces. In this work, we use the Lattice Boltzmann method (LBM) to study flow past a confined cylinder, placed in a microchannel. The LBM is a mesoscopic method capable of solving flow in micro scales. Applying the Maxwellian scattering kernel, the slip velocity is modeled on the channel and cylinder walls appropriately. We compare the results of solving the flow in a pressure driven microchannel and the macroflow past a square cylinder with the available results. Comparing with other numerical and analytical available solutions, there are relatively good agreements. Additionally, the results show that the drag coefficient decreases in all ranges of blockage ratios due to rarefaction effects. We define an effective parameter and analyze the effect of blockage ratio on rarefaction. The current results also indicate that the drag coefficient reduction due to rarefaction effect is higher for lower blockage ratios, which have important applications such as particle transport
  9. Keywords:
  10. Lattice Boltzmann Method ; Knudsen Number ; Microchannel ; Nanoparticles ; Microelectromechanical Systems (MEMS)

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