NUMERICAL MODELLING OF INHALER SPACERS: A NOVEL STUDY

摘要

The purpose of this paper is to report the development and the first stages of validation of a model for a spacer device, used to aid inhalation of various drugs. The aim is to understand the fluid and/or particle behaviour within such a device. In the present study of the spacer, both two- and 3-dimensional studies have been undertaken, using the commercial CFD engines PHOENICS and CFX-4.1. The paper reports on the findings of the study carried out, in terms of grid dependency of the results, sensitivity of the flow patterns to the inlet conditions. Finally, the outcome of the initial results obtained with shorter spacer geometry is also presented. A number of inlet conditions were investigated, these ranged from simple straight jets to spanning jets with variable angles. Results are presented in the form of velocity profiles, within the spacer; concentration distribution at various time-shots in the spacer and comparisons with experimental data, where available. The results showed good agreement between codes and with experimental data where available. It has been shown that the inlet conditions are very important in obtaining optimum mixing within. Furthermore, this also predicts the optimum time at which the patient should breath in to obtain a maximum dosage.