Abstract
We investigate experimentally the characteristics of the flow field that develops at low Reynolds numbers (Re ≪ 1) around a sharp 90 corner bounded by channel walls. Two-dimensional planar velocity fields are obtained using particle image velocimetry (PIV) conducted in a towing tank filled with a silicone oil of high viscosity. We find that, in the vicinity of the corner, the steady-state flow patterns bear the signature of a three-dimensional secondary flow, characterized by counter-rotating pairs of streamwise vortical structures and identified by the presence of non-vanishing transverse velocities (u z). These results are compared to numerical solutions of the incompressible flow as well as to predictions obtained, for a similar geometry, from an asymptotic expansion solution (Guglielmini et al., J. Fluid Mech., vol. 668, 2011, pp. 33-57). Furthermore, we discuss the influence of both Reynolds number and aspect ratio of the channel cross-section on the resulting secondary flows. This work represents, to the best of our knowledge, the first experimental characterization of the three-dimensional flow features arising in a pressure-driven flow near a corner at low Reynolds number.
Original language | English (US) |
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Pages (from-to) | 37-52 |
Number of pages | 16 |
Journal | Journal of Fluid Mechanics |
Volume | 707 |
DOIs | |
State | Published - Sep 25 2012 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Applied Mathematics
Keywords
- Stokesian dynamics
- general fluid mechanics
- low-Reynolds-number flows