get_settling Subroutine

public subroutine get_settling(xt, yt, zt, nsp, settling)

                                                                        *

This subroutine calculates particle settling velocity. * * Author: A. Stohl * * May 2010 * * Improvement over traditional settling calculation in FLEXPART: * generalize to higher Reynolds numbers and also take into account the * temperature dependence of dynamic viscosity. * * Based on: * Naeslund E., and Thaning, L. (1991): On the settling velocity in a * nonstationary atmosphere, Aerosol Science and Technology 14, 247-256. * * Changes * Daria Tatsii 2022: implementation of shape factor according to * Bagheri & Bonadonna 2016 *

                                                                        *

Variables: * itime [s] current temporal position * xt,yt,zt coordinates position for which wind data shall be cal- * culated * * Constants: * dfdr fluid density/particle density * Veq [m^3] equivalent volume of a sphere * dcyl [m] diameter of a cylinder (fiber) * f flatness parameters, S/I * e elongation parameters, I/L * Fs Stokes form factor, f e^1.3 * Fn Newton's form factor * Ks Stokes' drag correction * vsp help variable * x aspect ratio of cylinder height to its diameter * * Variables: * c_d drag coefficient * settling [m/s] settling velocity *

Arguments