Flow-excited membrane instability at moderate Reynolds numbers

Shear layer instability at low reynolds numbers

Turbulent pipe flow at extreme Reynolds numbers.

Both the inherent intractability and complex beauty of turbulence reside in its large range of physical and temporal scales. This range of scales is captured by the Reynolds number, which in nature and in many engineering applications can be as large as 10(5)-10(6). Here, we report turbulence measurements over an unprecedented range of Reynolds numbers using a unique combination of a high-press...

Viscous Flow at High Reynolds Numbers

Let us first give a heuristic estimates of boundary layer in steady flows. Consider a particle near the wall to be influenced by viscosity. After traveling a distance x from the edge, it has been under viscous influence for a time of t = x/U . Let U be large. For finite x, t is small so that vorticity is spread sideways to the width (νt) ∼ (νx/U). Let us define this width to be the boundary lay...

Sedimentation of Oblate Ellipsoids at low and Moderate Reynolds numbers

In many applications to biophysics and environmental engineering, sedimentation of non-spherical particles for example: ellipsoids, is an important problem. In our work, we simulate the dynamics of oblate ellipsoids under gravity. We study the settling velocity and the average orientation of the ellipsoids as a function of volume fraction. We see that the settling velocity shows a local maximum...

Impinging laminar jets at moderate Reynolds numbers and separation distances.

An experimental and numerical study of impinging, incompressible, axisymmetric, laminar jets is described, where the jet axis of symmetry is aligned normal to the wall. Particle streak velocimetry (PSV) is used to measure axial velocities along the centerline of the flow field. The jet-nozzle pressure drop is measured simultaneously and determines the Bernoulli velocity. The flow field is simul...