Capillary

Parameters for aerosol penetration through a fine capillary tube via convective diffusion (Dahneke 1983, Section 9). Computes the velocity-profile normalization factor σ and the dimensionless tube length z' = DL/(σv̄R²) from which the penetration fraction ϕ(z') = Σ B_i exp(−ω_i² z') can be evaluated using the tabulated eigenvalues in Tables 3–5 of the reference. Migrated from Aerosol.jl src/dahneke_brownian_diffusion.jl:372.