The TWIN project proposes a study of the coupling of inertial particles with the aerodynamics of Ahmed bodies. Using a strategy that combines the complementarity of four institutions such as the PRISME, LMFL, LEGI and CSTB laboratories, the effect of inertial particles on wakes will be studied experimentally, including the study of near-wall effects. Our aim is therefore to gain knowledge of particle accumulation effects for turbulent near and far wakes, and a better understanding of the effect of turbulence on cluster formation under real environmental conditions. To this end, joint measurements will be carried out in the wind tunnels of the three laboratories to fully characterize the single-phase and two-phase flows involved. Finally, the complementary nature of the three partners' facilities will enable real-life tests to be carried out in a climatic wind tunnel at CSTB. The TWIN project is structured in three parts: the first is dedicated to the study of the interactions of inertial droplet-like particles on the solid surface of Ahmed's body, the second concerns the influence of roughness models representative of droplet impacts on near and far wakes, and the third part of the project will enable all the mechanisms studied to be apprehended under realistic conditions.