Effect of moving boundary on fluid flow

The peristaltic pumping through channels with vibrating walls has been studied. The vibrations take the form of traveling waves. The spectrally accurate algorithm used to study flow properties is based on the Fourier expansions in the flow direction, Chebyshev expansions in the transverse direction, and the immersed boundary conditions (IBC) concept to deal with the irregular form of the solution domain associated with the waves. The flow domain is immersed in a regular computational domain. The flow boundary conditions are imposed in the form of constraints. Effectiveness of peristaltic pumping is assessed by determining the variation in the flow rate created by the wall vibrations. The study includes analysis of vibrations of just one wall as well as both walls. The effects of variations of the wave wavenumber, its amplitude, and the phase speed are analyzed. The effect of the relative position of the waves on different walls is studied in the case of the two wall vibrations. The results show that the flow rate is nearly constant and marginally dependent on the wave wavenumber as long as this wavenumber is sufficiently small but rapidly increases when the wavenumber becomes larger than one. The flow rate increases proportionally to the second power of the wave amplitude and proportionally to the first power of the wave phase speed. The largest flow rate is achieved for the two-wave system when the phase difference between both waves is equal to the half of their wavelength

磁場の制御を用いた磁性流体による変形ロボットシートの研究

筑波大学 (University of Tsukuba)201