Description of the tasks or assignment:
In Medspray inhalers droplets are generated using a silicon based nozzle plate inside an aerosol mix chamber. The aerosol mix chamber slows down the uniform droplets generated and adds these to the inhaled air stream. Using pressurized liquid, jets are formed through these nozzles. The jets breakup into droplets by means of Rayleigh breakup.
The starting pressure is dependent on the momentum of the jets. At low pressure (low velocities), the jets don’t have sufficient energy to come free from the surface. And as a result, the nozzle is drooling. At a higher pressure, the jets gain momentum and are able to lift off the drooling droplet. For an efficient spray nozzle, the drooling droplet is as small as possible.
In the assignment the influence of various parameters on the start behavior of the will be studied. Physical models may be made, as well experiments with a camera can be done. Results will be analysed. Suggestions for design rules will be made.