The next generation of commercial aircraft will require an efficient design loop on which unsteady aerodynamics is heavily involved: these include aerodynamics and aeroacoustics on fixed and mobile surfaces such as landing gear, high-lift system, FAN, compressor, turbine, wind turbine and open-rotor. CERFACS proposed to reach this objective by means of high-fidelity CFD methods (based on Large Eddy Simulation -LES- approach), which represents a breakthrough compared to industrial standards, which are based on the steady or unsteady Reynolds-Averaged Navier Stokes (RANS) turbulence modelling. To make the use of LES in industry attractive, a lot of effort have to be done to reduce the CPU cost. Efforts must be made in different directions: numerical discretization (to get the best accuracy for a given CPU time), mesh generation, turbulence modelling, co-processing and HPC efficiency on different platforms (CPU and GPU).
Among all possible CFD approaches, CERFACS is involved in two promissing ones: Lattice Boltzmann Method (LBM) and high-order discontinuous approach such as Spectral Difference Method (SDM). CERFACS believe that these approaches have a great potential to dramatically reduce the simulation cost compared to traditional CFD formalisms. In this respect, comparisons are made with the standard CFD solvers available at CERFACS.
Here is an example of an aeroacoustic simulation around a full aircraft using an LBM approach. The use of Cartesian grid with immersed boundary method makes the use of LBM the most promising approach in term of restitution time for LES simulations.