Florent Renac

Research scientist in numerical simulation and aerodynamic shape optimization at ONERA (Computational Fluid Dynamics and Aeroacoustic Dept. DSNA).

- Contributions to discrete implicit gradient and adjoint methods for aerodynamic shape optimization; implementation in the elsA software package based on object-oriented solutions for CFD.

- Theoretical skills: finite volume methods; Newton method; direct methods for linear systems (LU decomposition).

- Programming languages: C++, Forttran 77/90, Python.

Post doctoral position at ONERA (Fundamental and Experimental Aerodynamics Dept. DAFE).

- Research : Linear temporal stability of a compressible vortex.

- Skills: theoretical analyses (asymptotic analysis) and numerical analyses (shooting method, finite differences, spectral collocation method) of differential equations modelizing compressible vortex flows.

Research collaborator at Trisonic Center (Istanbul Technical University, Turkey) within the project T126 of NATO-RTA (Research Technical Agency of NATO).

Research field: Experimental investigation (visualizations) of the compressible vortical flow field around a delta wing.

- Thesis: "Experimental control of vortex breakdown over a rounded leading edge delta wing."
This work awarded the "Prix de Thèse DGA 2004." See www.recherche.dga.defense.gouv.fr/fr/rencontre_...

- Research: This study concerns the fluidic control of the leading-edge vortices over a 60° sweep angle delta wing with a rounded leading-edge. Firstly, we report experimental measurements on the flow field to characterize the effects of the geometry. Laser Doppler Velocimetry allows the analysis of the linear stability of the vortices. The results of the nominal test conditions establish a basis for studying the influence of the flow control. Secondly, we apply a pulsed or steady blowing at the leading-edge through thin slots whose frequency and momentum flux are variable. Pulsed blowing is not effective to affect the global characteristics of the flow field. However, the steady control results in the upstream shift of the vortex breakdown location and increases the maximum normal force and pitching moment. An asymmetric control produces a significant rolling moment around certain incidence angles.

- Experimental methods: Laser Doppler velocinetry LDV, hot wire velocimetry, pressure sensitive paint PSP.

- Theoretical methods: spectral analysis, hydrodynamic stability, linear stability.