My past and present research activities consist in proposing and studying efficient numerical methods applicable to resolution of a wide range of partial differential equations (PDEs) and optimization problems. In particular, in the past four years, I have been developing • algebraic multigrid methods by smoothed aggregation: an efficient multigrid solver of sparse systems of linear equations. The main application fields have been compressible and incom-pressible fluid simulations, linear elasticity, and electromagnetism. • shape optimization algorithms: conception of multi-level parametrization techniques to ac-celerate convergence of standard optimization methods. The main application area was the aerodynamic design of a small business je...