Current progress on the numerical simulation of detached flows around airplanes

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Some investigations of domain decomposition techniques in parallel CFD

. Domain decomposition methods in ønite element applied aerodynamics provides a real speed-up of the convergence and good parallel scalability, even with the minimum overlap approach used here. Furthermore, a new variant of Restricted Additive Schwarz procedure is tested and shows a very attractive scalability property. 1 Introduction With the emergence of the parallel distributed memory computers, certain techniques of convergence acceleration, expensive in memory, present a renewed interest for the industrial applications. Exploitation of these techniques on this type of architecture led to the use of domain decomposition decomposition techniques. This article presents the results obtained on a code of aerodynamics where we successively consider: 1. Convergence acceleration on uni-processor with a basic preconditioner (i.e. ILU(0)). 2. The analyze of the behavior of the iteration process in parallel with a domain decomposition method while trying to minimize the communication betwee..

Comparison stripmap COSMOS SkyMed X-band and tops Sentinel-1 C-band in estimating ground subsidence using irstea TOMOSAR platform: Ho Chi Minh City case study

International audienceThe objective of this paper is to provide a better understanding of Persistent Scatterers Interferometry (PSI) capabilities in subsidence estimations of TOPSAR Sentinel-1 data. This work has presented an advanced PSI analysis, to provide unprecedented spatial extent and continuous temporal coverage of the subsidence in Ho Chi Minh City by using 49 stripmap Cosmos SkyMED (CSK) X-band and TOPS Sentinel-1 Cband 23 images acquired from 2014 to 2016. The analysis was carried out by using the Irstea TomoSAR platform, which supports the entire processing from SAR, Interferometry, Polarimetry, to Tomography (so called TomoSAR). The study shows that the performance of stripmap CSK and TOPS Sentinel-1 is quite similar and effective to detect the subsidence phenomena. Subsidence is most severe in the Holocene silt loam areas along Sai Gon river and in the Southwest of the city, with the maximum value up to-30 mm/yr, similar with the previous study using ALOS PALSAR. Index Terms-Synthetic Aperture Radar, TOPS Sentinel-1, Comos SkyMED, TomoSAR platform, service as demand, subsidence, Ho Chi Minh City, Vietnam

Application of sonic boom optimization to supersonic aircraft design

Preliminary results on shape optimization of a wing-body configuration aiming at reducing sonic boom overpressure will be discussed. The optimization process uses a CAD modeler and an Euler CFD code with adjoint. Thickness, scale, twist and camber at section level were used to obtain gains in ground pressure signature

Computational and Experimental Assessment of Models for the First AIAA Sonic Boom Prediction Workshop Using Adaptive High Fidelity CFD methods

International audienceThe first sonic boom prediction workshop which was held in January 2014 has issued three test cases to be compared by a wide range of participants from the international sonic boom community, each one using their own numerical methodology. The present paper is dedicated to the analysis of the results obtained using three different solvers: CEDRE, ENGENIE and WOLF. What is meant here is to assess the sensitivity of the flow pressure perturbation used for acoustic propagation with respect to usual CFD ans mesh practices. Moreover, this work is a contribution toward building up the knowledge allowing being able to say what can be considered as a valid numerically predicted near field pressure