Experimental Investigation of the Air and Droplet Dynamics of a Soft Mist Inhaler

This presentation reports high-fidelity measurements of the airflow and water-droplet mist generated by a pre-filled syringe soft mist inhaler. Using 2C–2D PIV for the seeded airflow and PTV for the unseeded droplet field, the study compares mouthpiece operation with and without homogeniser airflow under a 2 kPa airflow pressure drop and 3.5 MPa droplet injection pressure. The results show that the droplet mist and airflow are strongly coupled, and that the homogeniser modifies the near-nozzle flow structure and downstream velocity profiles. These measurements provide detailed velocity and droplet-distribution data that can support soft mist inhaler design by helping to minimise mouth–throat deposition and improve aerosol delivery to the lungs.