Scale height of the particle layer H_p (top panels) and maximum of the local particle density ρ_p (bottom panels) as a function of time for all our 3D models. Each column represents one set of dimensionless stopping time τ_s and solid abundance Z. All the models have a computational domain of 0.2H on each side. Different line colors represent different resolutions. The dotted lines are obtained by first averaging over the azimuthal direction before taking the maximum of ρ_p.