Dispensing aerosols
In general are dispensing aerosols used for the treatment of chronic and acute diseases of the respiratory system. Using inhalers medical substances reach the bronchi directly. The active substances and auxiliary agents dissolved in the fluid-phase foaming agent are very finely pulverised through the spontaneous evaporation of the propellant. This substance cloud reaches the bronchi with each spray thrust.
Object - In conventional dispensing aerosols only a small part of the active substances (approximately 20%) reaches the bronchi. Increasing the effective portion of aerosols, therefore, comprises a major objective when developing new dispensing aerosols or optimising existing ones.
Method - The relative complex problem represented by the dispensing aerosol spraying process can be modelled using modern numerical flow simulation methods, while taking account of the two-phase character of the transient flow.
The results of the simulation allow a detailed analysis of the time-dependent, three-dimensional velocity and particle distributions in the dispensing aerosol. A targeted optimisation of the device can be undertaken on the basis effective parameter variation simulations for the specific inhaler, which, in this form, can not be obtained from experiments.