Latest papers in fluid mechanics
Author(s): Arjun Sharma, Prasun K. Ray, and Demetrios T. Papageorgiou
An investigation finds that instability in gravity-driven thin viscoelastic films can be substantively enhanced or suppressed by sinusoidal wall topography with an appropriately chosen wavelength. Topography also introduces finer temporal scales in the film dynamics, and simulations produce a broad range of nonlinear states.
[Phys. Rev. Fluids 4, 063305] Published Mon Jun 24, 2019
Author(s): Arman Sadeghi, Milad Azari, and Steffen Hardt
The ion partitioning effect due to polyelectrolyte layer (PEL)-electrolyte permittivity contrast in soft microchannels leads to depletion of electrolyte ions within the PEL. This effect, surprisingly, magnifies the electroosmotic flow rate because of the space charge increase outside the PEL.
[Phys. Rev. Fluids 4, 063701] Published Mon Jun 24, 2019
Author(s): Marco Edoardo Rosti, Mehdi Niazi Ardekani, and Luca Brandt
A suspension of rigid particles in plane Couette flow with elastic boundaries is simulated numerically. Reduction in apparent viscosity for the more deformable boundaries is modeled as a concentration reduction as the volume for particles expands in amount equal to the boundary elastic deformation.
[Phys. Rev. Fluids 4, 062301(R)] Published Fri Jun 21, 2019
Author(s): Endao Han, Liang Zhao, Nigel Van Ha, S. Tonia Hsieh, Daniel B. Szyld, and Heinrich M. Jaeger
High-speed ultrasound imaging is used to reconstruct the three-dimensional flow field of dense cornstarch suspensions under tilted impact. Experiments show how jamming fronts propagate and get deformed in a nonaxisymmetric manner under different impact angles.
[Phys. Rev. Fluids 4, 063304] Published Fri Jun 21, 2019
Group theory analysis of early-time scale-dependent dynamics of the Rayleigh-Taylor instability with time varying acceleration
Author(s): Desmond L. Hill, Aklant K. Bhowmick, Dan V. Ilyin, and Snezhana I. Abarzhi
Group theory analysis of the Rayleigh-Taylor instability with an acceleration varying in time finds that the early time behavior depends on whether the acceleration decays faster or slower than 1/t2.
[Phys. Rev. Fluids 4, 063905] Published Fri Jun 21, 2019
Resonant response and optimal energy harvesting of an elastically mounted pitching and heaving hydrofoil
Author(s): Yunxing Su and Kenneth Breuer
Experiments using a cyber-physical hydrofoil, tested over a wide range of stiffness and damping coefficients, reveal that the optimal response is achieved at the structural resonant frequency where the leading-edge vortex formation is synchronized with the foil pithing and heaving.
[Phys. Rev. Fluids 4, 064701] Published Thu Jun 20, 2019
Author(s): Yayun Wang, Adam Sierakowski, and Andrea Prosperetti
Numerical simulations of turbulent flow past a sphere immersed in decaying turbulence, free to rotate around a fixed center, are presented. This arrangement allows the same simulations with and without the sphere, thus permitting the identification of the flow features that most affect the sphere rotation.
[Phys. Rev. Fluids 4, 064304] Published Wed Jun 19, 2019