Abstract Background: Transtracheal jet ventilation is an alternative ventilatory approach in airway surgery. The purpose of this study was to compare respiratory efficacy of percutaneous transtracheal with endotracheal, low frequency jet ventilation during microlaryngeal surgery. Methods: Ninety ASA class I-II patients aged between 16 and 70 years undergoing elective microlaryngeal surgery wer...

The variability of the zonal mean flow in the Southern Hemisphere during the period 1985–94 is studied using European Centre for Medium-Range Forecasts analyses. The dominant mode of variability has approximately equivalent barotropic variations of opposite signs centered at 408 and 608S. This structure is dominant in all seasons and has similar variance in all seasons. The temporal variance of...

SUMMARY An analysis is presented of measurements made at RAE in 1957-1959 on a series of delta wings. Lift and drag have been measured by strain-gauge balance at Mach numbers between 1.4 and 2.8. On some of the wings surface pressure distributions have also been measured. This Report deals mainly with the zero-lift wave drag, but also gives information on skin friction drag and lift-dependent d...

Cavitation inception in the near-field of high Reynolds number axisymmetric jets is analyzed using a simplified computational model. The model combines an axisymmetric vorticitystreamfunction finite-difference scheme for the simulation of the unsteady flow field. Using a simplified representation, microscopic bubbles are injected at the jet inlet. The motion of these bubbles is tracked in a Lag...

Flow control—the control of turbulence and turbulent flows, in particular— may be likened to the exercise of cupping water between two arthritic hands: frustratingly difficult and, at best, only partially successful. Harder still, innovative control concepts that are eventually brought to fruition in a laboratory setting face the additional, often major, obstacle of being translated into practi...

The paper examines eight diverse regimes in which fuels can mix and react with air. These comprise: (i) Lifted subsonic; (ii) supersonic jet flames, (iii) without (iv) cross flows; (v) Rim-attached flames; (vi) Early Downwash (vii) Downwash-attached (viii) Fire Whirls. Correlations of characteristics within these are principally terms a dimensionless Flow Number, U*, Cross Reynolds number, Rec,...

Keywords: MHD flow control Nonlinear boundary control Active mixing enhancement Distributed parameter systems a b s t r a c t A nonlinear Lyapunov-based boundary feedback control law is proposed for mixing enhancement in a 2D magnetohydrodynamic (MHD) channel flow, also known as Hartmann flow, which is electrically conducting, incompressible, and subject to an external transverse magnetic field...

This paper describes the fundamental motivation and ideas surrounding current developments in available energy-based methods for vehicle design, which are a class of methods allowing direct estimation of the total cost chargeable to each loss mechanism in any general vehicle design (land, sea, air, or space). It is shown that losses can be expressed in terms of chargeable fuel weight. These are...

ABSTRACT We present small-scale 3D hydrodynamical simulations of the evolution a 0.3 M⊙ main-sequence (MS) star that launches two perpendicular jets within envelope 0.88 red giant (RG). Based on previous large-scale simulations, we study dynamics either when secondary is grazing, it has plunged-in, or well RG (in each stage for ∼11 d). The through common (CE) depend conditions environment as th...

Control of jets has been studied for over a century and even today continues to be a significant research topic. It finds applications in various fields especially in aerospace, where enhancement of mixing characteristics of a jet can improve the performance greatly. Review articles by Gutmark et al.;1 Gutmark & Grinstein;2 Seiner et al.;3 Glezer & Amitay;4 Reynolds et al.;5 Ginevsky Vlasov & K...