Rotation Effects on Dynamics of Fluid Flow through Microchannels

  • Author / Creator
    Gheshlaghi, Behnam
  • Effect of rotation on dynamcis of flow in microchannels is studied. In the frist study, an analytical solution is developed for the unsteady flow of fluid through a parallel rotating plate microchannel, under the influence of electrokinetic force using the Debye–Hückel (DH) approximation. Transient Navier-Stokes equations are solved exactly in terms of the cosine Fourier series by the separation of variables method. The effects of frame rotation frequency and electroosmotic force on the fluid velocity and the flow rate distributions are investigated. The rotating system is found to have a damped oscillatory behaviour. It is found that the period and the decay rate of the oscillations are independent of the DH parameter (κ). Furthermore, the rotation is shown to genearte a secondary flow and the ratio of flow in y and x directions is examined. It showed that both angular velocitiy and the Debye-Hückel parameters are influential on the induced transient secondary flow in the y direction. At high values for Debye-Hückel parameter and the roatation parameter the flow rates in x and y directions are found to be identical. In the second study, an analytical model is provided to describe the filling dynamics of a capillary filled with a viscous fluid containing spinning particles. The presence of spinning particles leads to making additional coefficients of viscosity, namely spin viscosity and vortex viscosity, which couples rotational and translational movements. Three different time stages have been noticed during the capillary filling phenomenon: inertia force dominated, visco-inertial, and viscous-dominated regions. The last two regions are found to be mainly affected by the spinning particles. An increase in the spin and vortex viscosities increased the viscous force and thus reduced the front position of the moving liquid. The results of this study are validated using the no-angular-momentum (NAM) base-case results in literature and an excellent agreement was observed.

  • Subjects / Keywords
  • Graduation date
    Spring 2016
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
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