ArceNuIX E PARTICLE FALLING RATES The determination of the fallin: rates for the faliout particles wac made by initially cclculating the terminal velocities ror purticles at vurious altitudes. a cclected renge of purticl« diumetere vas used in making there ctlculations, The diameters considered were: 50, 75, 100, 160, 200, 2£0, 375, SCO, 750, aud 1000 B, 10, 25, Terminal ve.o- cities for there varticles were calculated for st.rting altitudes at 5000 ft increments from 0 to 100,000 ft. From these duta the averice rates of full of the :articles throush £000 ft increments of the atros- phere were determined. The calculation of the terminzl velocities involvei the uce of known lavs of settling of cusrenicd sarticlss from causes, The tyes of flow which there perticles underge urs dividea inte three regions: streamline, where vircous forces ;redonminste; intermediate; una turtulent, where inertia forces predominate. ing there types of flow are:3/ ~e Sow: Streamline motion, mntermediate region, Turbulent region, In simplified tor, the laws sovern- Wn : Ke (£6) a2 yo} (E.1) Po . - 2 ~ + Ym = KI (P= Po) [3 y 1/34 - oO = Bex 7 ty = hy (PLA)? alle (6.3) Po Vy = terminal velocity K = conetant, for irresuler quertsz particles: % = 36, Ky = 17,2 ard Kp = 50. P aensity of the particle f = density of the fluid d = true diameter y L = kinematic viscosity = te 137