The airflow in the modeled glottal constriction was simulated by the solutions of the Navier-Stokes equations for laminar flow, and the corresponding Reynolds equations for turbulent flow in generalized, nonorthogonal coordinates using a numerical method. A two-dimensional model of laryngeal flow is considered and aerodynamic properties are calculated for both laminar and turbulent steady flows...

Background—Steady laminar flow is atheroprotective, in part because of its antiinflammatory effects on vascular endothelial cells (ECs). We studied the activation of peroxisome proliferator–activated receptor(PPAR ) in ECs in response to laminar flow and the associated antiinflammatory effect. Methods and Results—Using flow channel with cultured ECs, we found that laminar flow activated the PPA...

The transition to turbulence in pipe and plane Couette flow differs from the better understood situation of Taylor-Couette or Rayleigh-Bénard flow in that the laminar profile is stable against infinitesimal perturbations for all Reynolds numbers. Moreover, even when turbulent flow is established, it can spontaneously return to laminar flow. These observations are compatible with the formation o...

Swifts are among the most aerodynamically refined gliding birds. However, the overlapping vanes and protruding shafts of their primary feathers make swift wings remarkably rough for their size. Wing roughness height is 1-2% of chord length on the upper surface--10,000 times rougher than sailplane wings. Sailplanes depend on extreme wing smoothness to increase the area of laminar flow on the win...

Three-dimensional simulations of the single-phase laminar flow and forced convective heat transfer of water in microchannels with small rectangular sections having specific hydraulic diameters and distinct geometric configurations were investigated numerically. The numerical results indicated that the laminar heat transfer was to be dependent upon the aspect ratio and the ratio of the hydraulic...

In this paper, the oscillating two-dimensional laminar flow about a cylinder and the oscillation of a cylinder in still water are studied. A finite volume method is applied to solve the Navier Stokes equations using SIMPLEC algorithm on a body fitted co-located O-type grid. In this study, the non-dimensional flow numbers, Keulegan-Carpenter and Stokes’ numbers are chosen over a range where diff...

BACKGROUND Steady laminar flow is atheroprotective, in part because of its antiinflammatory effects on vascular endothelial cells (ECs). We studied the activation of peroxisome proliferator-activated receptor-gamma (PPARgamma) in ECs in response to laminar flow and the associated antiinflammatory effect. METHODS AND RESULTS Using flow channel with cultured ECs, we found that laminar flow acti...

INTRODUCTION To simulate blood flow provided by the intracoronary shunt tube, and to clarify whether this method is actually suitable for Off-pump coronary artery bypass (OPCAB), we investigated the efficacy of the intracoronary shunt tube in a theoretical model on the basis of fluid dynamics. METHODS Fluid dynamics analysis was performed to simulate flow decrease after attachment on an intra...

BACKGROUND Factors affecting the efficacy of platelet and red blood cell (RBC) transfusion in patients undergoing hematopoietic stem cell transplantation (HSCT) have not been studied extensively. We aimed to evaluate platelet and RBC transfusion efficacy by measuring the platelet corrected count increment and the hemoglobin increment, respectively, 24 h after transfusion in 105 patients who rec...

in this numerical study the the heat transfer and laminar nanofluid flow in the three-dimensional microchannels with triangular cross-section is simulated. for increase the heat transfer from the walls of the channel, semiattached & offset mid- truncated rib,s placed in the canal, and the tooth geometry and the impact is studied. in this study, the water is base fluid, and the influence of the ...