Viral Loads in Clinical Specimens and SARS Manifestations

The number of anatomical sites with detectable viral loads by RT-qPCR appeared to correlate with death risk

The accuracy of surrogate decisions in intensive care scenarios

Anaesthesia and Intensive Care35146-51AINC

Design and numerical investigation of swirl recovery vanes for the Fokker 29 propeller

Swirl recovery vanes (SRVs) are a set of stationary vanes located downstream from a propeller, which may recover some of the residual swirl from the propeller, hoping for an improvement in both thrust and efficiency. The SRV concept design for a scaled version representing the Fokker 29 propeller is performed in this paper, which may give rise to a promotion in propulsive performance of this traditional propeller. Firstly the numerical strategy is validated from two aspects of global quantities and the local flow field of the propeller compared with experimental data, and then the exit flow together with the development of propeller wake is analyzed in detail. Three kinds of SRV are designed with multiple circular airfoils. The numerical results show that the swirl behind the propeller is recovered significantly with Model V3, which is characterized by the highest solidity along spanwise, for various working conditions, and the combination of rotor and vane produced 5.76% extra thrust at the design point. However, a lower efficiency is observed asking for a better vane design and the choice of a working point. The vane position is studied which shows that there is an optimum range for higher thrust and efficiency.Aerodynamics, Wind Energy & PropulsionAerospace Engineerin

Design and Experimental Validation of Swirl Recovery Vanes for Propeller Propulsion Systems

Flight Performance and PropulsionAerospace EngineeringWind Energ

Aerodynamic and Aeroacoustic Effects of Swirl Recovery Vanes Length

A numerical investigation of a propeller with swirl recovery vanes, for which experimental data exist, is performed. A second swirl recovery vane geometry, with shorter vanes to avoid the impingement of the propeller tip vortices, is also investigated. For the baseline swirl recovery vanes, the efficiency of the propulsive system increases by 2.4% with respect to the isolated propeller. This is obtained by converting angular momentum in axial momentum. A reduction of the swirl angle in the near wake by 48% is found. Most of the thrust is generated at the root of the vanes. Leading-edge impingement noise is the dominant source. The vanes cause noise to increase by 20 dB with respect to the isolated propeller in the axial direction, where noise from the propeller vanishes. In the axial direction, sound pressure level spectra show tonal peaks at harmonics of the second blade passing frequency, while in the other directions, peaks are present at harmonics of the first blade passing frequency. However, the overall isolated propeller noise is 23 dB higher than the noise generated by the swirl recovery vanes. Shortening the vane length causes a 13% reduction of the thrust generated by the vanes with respect the baseline case but no variation of the far-field noise.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Wind EnergyFlight Performance and Propulsio

Prevalence and genetic diversity of coronaviruses in bats from China

10.1128/JVI.00697-06Journal of Virology80157481-749