. 2020 Jun 1;32(6):063303. doi: 10.1063/5.0015044

TABLE I.

Regime transition state of the local interaction modes for a saliva droplet impacting a fibrous porous filter. α = 2630 and β = 0.183 were measured and reported for water droplets impacting on a dry surface.^45,46 α = 1320 and β = 0.183 were reported for water droplets impacting on a wet surface;^45,46 ${W e_{c}}_{1} = 0$ and ${d_{p}}_{c} = 60 μ m$ .

Interaction mode (see Fig. 5)	Condition	Critical number
Stick	$E_{K S} < {W e_{c}}_{1}$	${W e_{c}}_{1}$
Splash/Rebound	$We \leq {W e_{c}}_{2}$	${W e_{c}}_{2} = α {La}^{- β}$
Penetrate	$d_{p} \leq {d_{p}}_{c}$	${d_{p}}_{c}$