Diffusion

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.

Combined gas-phase and interfacial mass transfer coefficient k_mt for gas-particle exchange. k_mt is the inverse of the total resistance to mass transfer, which is the sum of two resistances in series: (1) gas-phase diffusion resistance tau_g = R_p²/(3 D_g), and (2) interfacial resistance tau_i = (R_p/3α) √(2πM_A/(RT)) arising from the finite accommodation probability and molecular speed. The reciprocal relation k_mt = 1/(tau_g + tau_i) (Seinfeld & Pandis 2006, Chapter 12, Eq. 12.116) determines the overall rate at which a gaseous species is transferred to or from the particle surface. Migrated from Aerosol.jl src/mass_transfer.jl `MassTransferCoefficient`.