Jordan P.,University of Poitiers |
Colonius T.,California Institute of Technology
Annual Review of Fluid Mechanics | Year: 2013
Turbulent jet noise is a controversial fluid mechanical puzzle that has amused and bewildered researchers for more than half a century. Whereas numerical simulations are now capable of simultaneously predicting turbulence and its radiated sound, the theoretical framework that would guide noise-control efforts is incomplete. Wave packets are intermittent, advecting disturbances that are correlated over distances far exceeding the integral scales of turbulence. Their signatures are readily distinguished in the vortical, turbulent region; the irrotational, evanescent near field; and the propagating far field. We review evidence of the existence, energetics, dynamics, and acoustic efficiency of wave packets. We highlight how extensive data available from simulations and modern measurement techniques can be used to distill acoustically relevant turbulent motions. The evidence supports theories that seek to represent wave packets as instability waves, or more general modal solutions of the governing equations, and confirms the acoustic importance of these structures in the aft-angle radiation of high subsonic and supersonic jets. The resulting unified view of wave packets provides insights that can help guide control strategies. Copyright © 2013 by Annual Reviews. All rights reserved. Source
French National Center for Scientific Research, University of Poitiers and University of Bordeaux Segalen | Date: 2011-12-16
The invention concerns screening molecules with anti-prion activity. More particularly, it concerns kits for screening molecules with anti-prion activity characterized in that they comprise in combination a [PSI+], phenotype yeast, an antibiogram and an agent for purifying prions at sub-efficient doses, said yeast including the ade1-14 allele of the ADE1 gene and an inactivated ERG6 gene, the screening methods, and a family of molecules with anti-prion activity isolated by the inventive screen. The invention is applicable to anti-prion agents for producing medicines in particular for treating neurodegenerative diseases involving protein aggregates.
University of Poitiers and French Institute of Petroleum | Date: 2011-07-29
A current reversible DC/DC double-boost quadratic converter, capable of performing high transformation ratios.
Snecma, French National Center for Scientific Research, University of Poitiers and Ensma | Date: 2014-07-08
The invention relates to a rear casing for a turbine engine comprising a primary body generating a primary flow (
University of Poitiers, French Institute of Petroleum and C.N.R.S. | Date: 2012-10-26
This invention describes a process for the production of middle distillates comprising at least one hydrocracking stage that oligomerizes a paraffinic feedstock produced by Fischer-Tropsch synthesis, said process using a catalyst that comprises at least one hydrogenating-dehydrogenating metal that is selected from the group that is formed by the metals of group VIB and group VIII of the periodic table, by themselves or in a mixture, and a substrate that comprises a beta zeolite in the form of crystallites with a mean size that is less than 100 nm dispersed in at least one porous mineral matrix, whereby said beta zeolite has a mesopore volume of less than 0.4 ml/g.