Résolution couplée des équations RANS 3D intégrées sur les Volumes Finis non structurés d'une grille primale et de ses duales. Application au 4ème atelier 'High Lift Prediction'

International audienceThis paper describes the main features of NextFlow ITW, a high-order reconstructed Finite Volume solver for turbulent flows of perfect gases. This code of the 'k-exact' family was worked out on the occasion of the High-Lift Prediction Workshop 4, it is based on reconstructed k1 to k3 polynomials and results in 2 nd order and 3 rd order FV schemes. One important characteristic is that it couples the discretization of the RANS equations on the unstructured primal grid (a multi-element grid with prisms, pyramids and tetrahedron) and on its dual grids (made of vertex-, edge-and face-centered Finite Volumes). 3 series of runs proposed by the Workshop were conducted with this solver and its 2D reduced version, their setup are described together with detailed results. Reference is made to the synthesis of all submissions prepared by the coordinator of the HO Technology Focus Group and the Workshop organizers

An optimized solver for unsteady transonic aerodynamics and aeroacoustics around wing profiles

International audienceThe extensive optimisation for HPC of Fluid Dynamics software is possible under a variety of aspects on GPU clusters within GPUDirect/C/CUDA/Thrust programming paradigms. In particular, our algorithm could be made more modular to adapt to the CUDA register usage limit, Thrust libraries provide highly efficient solutions on global memory computations and warp collaboration through shared memory proves crucial. Large Eddy Simulation, based on basic principles of field mechanics, despite its very high computing requirements, complements Reynolds-Averaged Navier-Stokes models, which lack versatility. In the field of aeronautical flows around wing profiles in steady or off-design configurations, our solver provides efficient solutions on 128-TESLA clusters for adequate 2-billion cell grids

Numerical Properties and GPU Implementation of a High Order Finite Volume Scheme

International audienc

Numerical Properties and GPU Implementation of a High Order Finite Volume Scheme

International audienc

Early and systematic administration of fibrinogen concentrate in postpartum haemorrhage following vaginal delivery: the FIDEL randomised controlled trial

Objective: To assess the benefits and safety of early human fibrinogen concentrate in postpartum haemorrhage (PPH) management. Design: Multicentre, double‐blind, randomised placebo‐controlled trial. Setting: 30 French hospitals. Population: Patients with persistent PPH after vaginal delivery requiring a switch from oxytocin to prostaglandins. Methods: Within 30 minutes after introduction of prostaglandins, patients received either 3 g fibrinogen concentrate or placebo. Main outcome measures: Failure as composite primary efficacy endpoint: at least 4 g/dl of haemoglobin decrease and/or transfusion of at least two units of packed red blood cells within 48 hours following investigational medicinal product administration. Secondary endpoints: PPH evolution, need for haemostatic procedures and maternal morbidity–mortality within 6 ± 2 weeks after delivery. Results: 437 patients were included: 224 received FC and 213 placebo. At inclusion, blood loss (877 ± 346 ml) and plasma fibrinogen (4.1 ± 0.9 g/l) were similar in both groups (mean ± SD). Failure rates were 40.0% and 42.4% in the fibrinogen and placebo groups, respectively (odds ratio [OR] = 0.99) after adjustment for centre and baseline plasma fibrinogen; (95% CI 0.66–1.47; P = 0.96). No significant differences in secondary efficacy outcomes were observed. The mean plasma FG was unchanged in the Fibrinogen group and decreased by 0.56 g/l in the placebo group. No thromboembolic or other relevant adverse effects were reported in the Fibrinogen group versus two in the placebo group. Conclusions: As previous placebo‐controlled studies findings, early and systematic administration of 3 g fibrinogen concentrate did not reduce blood loss, transfusion needs or postpartum anaemia, but did prevent plasma fibrinogen decrease without any subsequent thromboembolic events

Comparison of Various CFD Codes for LES Simulations of Turbomachinery: From Inviscid Vortex Convection to Multi-Stage Compressor

peer reviewedSome possible future High Fidelity CFD codes for LES simulation of turbomachinery are compared on several test cases increasing in complexity, starting from a very simple inviscid Vortex Convection to a multistage axial experimental compressor. Simulations were performed between 2013 and 2016 by major Safran partners (Cenaero, Cerfacs, CORIA and Onera) and various numerical methods compared: Finite Volume, Discontinuous Galerkin, Spectral Differences. Comparison to analytical results, to experimental data or to RANS simulations are performed to check and measure accuracy. CPU efficiency versus accuracy are also presented. It clearly appears that the level of maturity could be different between codes and numerical approaches. In the end, advantages and disadvantages of every codes obtained during this project are presented

Loss-of-Function Mutations in RSPH1 Cause Primary Ciliary Dyskinesia with Central-Complex and Radial-Spoke Defects

International audiencePrimary ciliary dyskinesia (PCD) is a rare autosomal-recessive respiratory disorder resulting from defects of motile cilia. Various axonemal ultrastructural phenotypes have been observed, including one with so-called central-complex (CC) defects, whose molecular basis remains unexplained in most cases. To identify genes involved in this phenotype, whose diagnosis can be particularly difficult to establish, we combined homozygosity mapping and whole-exome sequencing in a consanguineous individual with CC defects. This identified a nonsense mutation in RSPH1, a gene whose ortholog in Chlamydomonas reinhardtii encodes a radial-spoke (RS)-head protein and is mainly expressed in respiratory and testis cells. Subsequent analyses of RSPH1 identified biallelic mutations in 10 of 48 independent families affected by CC defects. These mutations include splicing defects, as demonstrated by the study of RSPH1 transcripts obtained from airway cells of affected individuals. Wild-type RSPH1 localizes within cilia of airway cells, but we were unable to detect it in an individual with RSPH1 loss-of-function mutations. High-speed-videomicroscopy analyses revealed the coexistence of different ciliary beating patterns—cilia with a normal beat frequency but abnormal motion alongside immotile cilia or cilia with a slowed beat frequency—in each individual. This study shows that this gene is mutated in 20.8% of individuals with CC defects, whose diagnosis could now be improved by molecular screening. RSPH1 mutations thus appear as a major etiology for this PCD phenotype, which in fact includes RS defects, thereby unveiling the importance of RSPH1 in the proper building of CCs and RSs in humans