We advance a quantitative description of the critical shear rate γ̇c needed to dislodge a spherical particle resting on a surface with a model asperity in laminar and turbulent fluid flows. We have built a cone-plane experimental apparatus which enables measurement of γ̇c over a wide range of particle Reynolds number Rep from 10−3 to 1.5 × 103. The condition to dislodge the particle is found to b...

We study experimentally the impact of inertial reference frame changes on overdamped Brownian motion. The are implemented by inducing, with a laser, laminar convection flows in column fluid where microspheres dispersed. flow plays role relative velocity between laboratory and comoving frames, enables us to analyse consequences Galilean transformations diffusion. verify particular how dynamics r...

Fluid and structural systems and their possible interaction have a rich array of behavior being susceptible to instabilities and thus the generation of limit cycle oscillations and on occasion chaotic response. in this talk we will touch on several example including solar sails, high performance aircraft and aerodynamic decelerators from space into planetary atmospheres. Much of the talk will b...

The properties of a relatively uncommon regime of fluid dynamics, low Mach number compressible flow are investigated. This regime, which is characterized by an exceptionally large tube aspect ratio L/d ~ 106 leads to highly subsonic flows in which friction dominates inertia. Even so, because of the large aspect ratio, finite pressure, temperature, and density gradients are required, implying th...

We present ultra-fast homogeneous mixing inside a microfluidic channel via single-bubble-based acoustic streaming. The device operates by trapping an air bubble within a "horse-shoe" structure located between two laminar flows inside a microchannel. Acoustic waves excite the trapped air bubble at its resonance frequency, resulting in acoustic streaming, which disrupts the laminar flows and trig...

We demonstrate how the speed of mixing under laminar conditions can be appreciably enhanced in concurrent centrifugal flows through straight, low-aspect-ratio microchannels pointing in radial direction in the plane of rotation. The convective mixing is driven by the inhomogeneous distribution of the velocity-dependent Coriolis pseudo force and the interaction of the soinduced transverse current...

A multigrid algorithm is combined with an upwind scheme for solving the twodimensional Reynolds-averaged Navier-Stokes equations on triangular meshes resulting in an efficient, accurate code for solving complex flows around multiple bodies. The relaxation scheme uses a backward-Euler time difference and relaxes the resulting linear system using a red-black procedure. Roe’s flux-splitting scheme...

Hypersonic laminar flow over a canonical 25°–55° double cone is studied using computational fluid dynamics and global stability analysis (GSA) with free-stream Mach number of 11.5 various unit Reynolds numbers. Axisymmetric simulations reveal that secondary separation occurs beneath the primary bubble beyond critical number. The numerical results agree well existing experiments triple-deck theo...

Static mixers are becoming increasingly popular because they energy-efficient, cost-effective, and easy to maintain. Mixing is an essential unit operation in many chemical industries. In this study, a modified high efficiency vortex static mixer was used examine laminar flows rectangular duct. To encourage fluid rotation improve mixing with heat transfer, the set rotated by angles of 0?, 5?, 10...

In an electrically conducting fluid two types of turbulence with a preferred direction are distinguished: planar turbulence, in which every velocity of the turbulent ensemble of flows has no component in the given direction; and two-dimensional turbulence, in which every velocity in the turbulent ensemble is invariant under translation in the preferred direction. Under the additional assumption...