Instabilities in rotating cylinders

Pre-filled medical syringes (or vials) are prepared via an automated process that requires drastic control measures. Indeed, during their preparation, small particles may find their way into the syringe which must then be detected before they can be safely released for public use. A common way to control the quality of pre-filled syringes is to rotate them around their axis to set its fluid content in motion and then to stop the rotation. At this point, inertia controls the flow and the presence of undesired particles can be identified via visual techniques.

Due to the important medical implications related to this quality control process, a good understanding of the flow is paramount. We will study numerically (and potentially experimentally) the instabilities occurring during the set up of the rotating flow when the syringe is set in rotation and during its relaxation when this rotation is stopped. The results will constitute a fundamental step toward the understanding and design of quality control measures for the preparation of pre-filled medical syringes.