Fig. 8.

The measured and predicted dilution factors vary with the distance from the discharge orifice. Prediction using the steady and two-stage jet models was made with five activity intensities and the discharge orifice as 0.02 m. The representative inhalation/exhalation rates listed in Table 1 were used. Note that for the steady jet model, the dilution factor is 1 when the distance is less than 0.12 m. The jet or puff flow in Ghaem-Maghami and Johari [29] and Behera et al. [28] was injected into an isothermal and isobaric chamber. The former was accompanied by a weak co-flow (a 0.5% of jet velocity) while the latter had no co-flow.