Résumé
By means of quasi-2D experiments and 2D numerical testswe investigate the particle flow around amoving intruder immersed into an ensiled granular material.The intruder (a blade)isfirst positioned at the bottom of a transparent box. The box is filled with glass beadsup to a fixed bed height. The intruder is then moved upward at constant velocity. The flow around the intruder is analyzed using a Particle Image Velocimetry (PIV) method,while a force sensor monitorsthe exerted vertical drag force. In the vicinity of the intruder, avalanches, lateral collapsing, compacted zones, shear banding... areclearly observed. These flow typologies are correlated to successive loading-unloading events in the force signal.As a function of the intruderdepth, three flow regimes of the particles can be distinguished: quasistatic, frictional and collisional.Regarding to numerical simulations, aDiscrete Element (DEM) approach was developed to clarify the force transmission at the scale of the contact between particles and with the intruder. Specific boundariesconditions wereprogramedto simulate the geometry of the experimental device,with different sizesof boxes and intrudersshapes. The grain flow and the forces acting on the intruder are computed during its ascending motion.Finally,both experimental and numerical parametric study were performed,in which the velocity of the intruderwasvaried.Based on these results the experimental and numerical flow regimes are compared and analyzed according to the force networks obtained by the DEM