We study the motion of an elastic capsule through a microchannel characterized by a localized constriction. We consider a capsule with a stress-free spherical shape and impose its steady-state configuration in an infinitely long straight channel as the initial condition for our calculations. We report how the capsule deformation, velocity, retention time, and maximum stress of the membrane are ...

The statistical characteristics and the evolution of backflow structures are investigated in wall-bounded flows at Reynolds numbers up to $Re_{\tau }=1000$ . is caused by joining large-scale high- low-speed vicinity wall formed tail tip structure. distribution density percentage area region on both increase with number. have an average lifespan 8 units which found be slightly longer pipe than c...

We examine interaction mechanisms between the drag-reducing streamwise-traveling waves of spanwise wall velocity applied at a turbulent channel flow, and near-wall coherent structures. In particular, we focus our analysis on drag-reduction-induced modifications quasi-streamwise vortices that populate region flows through conditional averaging procedure. observe that, while share most with oscil...

Sets of stereo PIV measurements were obtained in streamwise-spanwise planes of a turbulent boundary layer with Reτ = 1060. Two-point spatial correlations obtained from fields in the logarithmic region revealed that both streamwise-streamwise (Ruu) and streamwise-wall-normal (Ruw) correlations were significant for streamwise displacements of more than 1500 wall units. Zero crossing data for the ...

Simulations of bifurcated three-dimensional laminar forced convection in horizontal duct with plane symmetric sudden expansion are presented to illustrate the effects of flow bifurcations on temperature and heat transfer distributions. The stable bifurcated flow that develops in this symmetric geometry leads to non-symmetric temperature and heat transfer distributions in the transverse directio...

Study objective: The objective was to determine whether external chest wall oscillation (ECWO) during sleep (1) reduced spontaneous ventilation while maintaining adequate gas exchange over several hours, (2) influenced the quality and distribution of sleep, and (3) increased the number of respiratory events. Design: Prospective controlled study with counterbalanced order of intervention. Settin...

A joint experimental–computational program examined low-frequency, spanwise oscillations in supersonic flow over a finite-width cavity. Lowpass-filtered rear wall surface pressure revealed that shear layer impingement was most often biased to one side of the wall, switching sides at frequency two orders magnitude below resonance. Therefore, bifurcation into spanwise-asymmetric, mirrored, quasi-...

Direct numerical simulations of wall-bounded flow reveal that turbulence production can be suppressed by a transverse traveling wave. Flow visualizations show that the near-wall streaks are eliminated, in contrast to other turbulence-control techniques, leading to a large shear stress reduction. The traveling wave can be induced by a spanwise force that is confined within the viscous sublayer; ...

The development of wall shear stress in Görtler vortex flow was investigated by hot-wire measurements. The wavelengths of the vortices were pre-set by thin vertical perturbation wires so to produce the most amplified wavelengths. Three different vortex wavelengths of 12 mm, 15 mm, and 20 mm were considered, and near-wall velocity measurements were carried out to obtain the “linear” layers of ve...