Softwares

Multi-fluid flows and application for complex fluids, microfluidics and biology

Participants: Charles-Henri Bruneau, Thierry Colin [correspondant], Mathieu Colin, Olivier Saut.

• Microfluidics
  This last 3 years we have built several codes for microfluidics. The forts one deals with bifluid Newtonian flows with surface tensor in channels, "T" junction and cross junction. We have 2D, 3D-axi-symetric and 3D version. We use a level set method for the evolution of the interface. These codes have been validated with comparison with experiments.
  The next step will be to construct a parallel solver for the Stokes equation with discontinuous coefficient adapted to our framework.
  
  
• Biology
  The numerical platform eLYSe is maturing. The platform is already used for our biological simulations. Work is still ongoing to finish abstracting the boundary conditions in the 3D version (which was completed for the 2D version). The platform is also being slightly adapted to have performance on par with a classical discretization on a cartesian mesh at the cost of a small increase of memory use. Some methods of eLYSe were also rewritten to take advantage of distributed architectures.

• A parallelized version of 2D and 3D Navier-Stokes solvers are in development.
  
  
• A Hybrid numerical code coupling DNS and Reduced Order Model based on Proper Orthogonal Decomposition is developed. This code is implemented for 2D incompressible NSE, based on the CH Bruneau code. The extension to 3D compressible flows will follow.
  
  
• Several codes for system identification based on low-order models are now available. They are based on a spectral representation of the inputs and outputs to be identified. These codes allowed us to devise accurate non-linear observers for two-dimensional flows. For three-dimensional complex flows the results still need to be improved.

Flow control and shape optimization

Participants: Michel Bergmann, Charles-Henri Bruneau [correspondant], Angelo Iollo, Iraj Mortazavi.

• Recent advances in Closed-Loop and Open-Loop flow control using vortex methods for high Reynolds number flows are implemented in a Vortex-In-Cell code in order to apply them easily to various control needs.
  
  
• 2D Shape optimization: bio-locomotion - optimization of fish like swimming, optimization of airfiol with flaps. Numerical tools based on vortex method, cartesian meshes, penalisation and level set methods.
  

Coupled transport-diffusion equations

Participant: Héloïse Beaugendre.

• Richards: 2D Finite Element code coupled to transport-diffusion equations of silica and oxygen.
  
  
• NSdes_SA module in FluidBox the ScAlApplix platform : 3D unstructured Finite Volume/Finite Element code to solve Navier-Stokes equations, parallel computing using MPI.