A natural laminar flow airfoil has been developed jointly by NASA's Dryden Flight Research and Langley Research Centers a s a part of the aircraft energy efficiency (ACEE) program. A NASA flight program incorporating this airfoil into partial wing gloves on the F-111 TACT airplane was scheduled to start in May, 1980. In support of this research effort, Boeing has conducted a n extensive boundar...

Laminar-turbulent breakdown in a swept-wing boundary layer is typically caused by secondary instabilities of steady crossflow vortices (CFVs). So far, boundary-layer suction for laminar flow control in three-dimensional boundary layers has been applied to reduce the crossflow and thus the growth of the primary vortices only. We investigate the influence of strong, localized suction (pinpoint su...

A brief review of laminar flow control techniques is given and a strategy for achieving laminarization for transonic transport aircraft is discussed. A review of some flight-test results on swept-wing transition is presented. It is also shown that polished leading edges can create large regions of laminar flow because the flight environment is relatively turbulence free and the surface finish r...

In this research we have implemented the Random Vortex Method to calculate velocity fields of fluids inside open cavities in both turbulent and laminar flows. the Random Vortex Method is a CFD method (in both turbulent and laminar fields) which needs the Schwarz-Christoffel transformation formula to map the physical geometry into the upper half plane. In some complex geometries like the flow in...

A central question in the dynamics of vortex lines in superfluids is dissipation on approaching the zero temperature limit T→0. From both NMR measurements and vortex filament calculations, we find that vortex flow remains laminar up to large Reynolds numbers Re{α}∼10(3) in a cylinder filled with 3He-B. This is different from viscous fluids and superfluid 4He, where the corresponding responses a...

Rationale: Endothelial cells (ECs) have distinct mechanotransduction mechanisms responding to laminar versus disturbed flow patterns. Endothelial dysfunction, affected by imposed flow, is one of the earliest events leading to atherogenesis. The involvement of / T lymphocytes in endothelial dysfunction under flow is largely unknown. Objective: To investigate whether shear stress regulates membra...

The present study aimed to investigate two numerical solutions of the Navier-Stokes equations. For this purpose, the mentioned flow equations were written in two different formulations, namely (i) velocity-pressure and (ii) vorticity-stream function formulations. Solution algorithms and boundary conditions were presented for both formulations and the efficiency of each formulation was investiga...

We previously reported that laminar flow activates peroxisome proliferator-activated receptor gamma (PPARgamma) in vascular endothelial cells in a ligand-dependent manner that involves phospholipase A2 and cytochrome P450 epoxygenases. In this study, we investigated whether epoxyeicosatrienoic acids (EETs), the catalytic products of cytochrome P450 epoxygenases, are PPARgamma ligands. Competiti...

Visual motion, such as radial optic flow, is an important cue for perceiving direction during ego-motion. Several previous studies have reported that the perceived speed of a radial optic flow is underestimated when the represented ego-motion direction between radial optic flow and non-visual (such as vestibular or/and proprioceptive) information is congruent. In the present study, we examined ...