On the motion of a small particle in the atmosphere
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Equations of motion, valid for a water droplet or a dust particle less than about 50Μm in radius moving through the air, are derived. Thus, the behaviour of a particle in some simple nonuniform fluid flows is discussed. In particular, it is found that a particle may follow an approximately closed trajectory in an axisymmetric flow about a horizontal axis. Thus, it is argued that turbulence should cause particles to fall at a much slower rate than their terminal velocity, even in the absence of a mean updraft.
KeywordsAtmosphere Dust Fluid Flow Small Particle Horizontal Axis
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- Basset, A. B.: 1888,Hydrodynamics, Vol. II, Deighton, Bell and Co.Google Scholar
- Basset, A. B.: 1910, ‘On the Descent of a Sphere in a Viscous Liquid’,Quart. J. Pure Appl. Math. 41, 369–381.Google Scholar
- Batchelor, G. K.: 1967,Fuid Dynamics, Cambridge University Press.Google Scholar
- Corrsin, S. and Lumley, J.: 1956, ‘On the Equation of Motion for a Particle in Turbulent Fluid’,Appl. Sci. Res. 6A, 114–116.Google Scholar
- Hinze, J. O.: 1959,Turbulence, McGraw-Hill.Google Scholar
- Kreyszig, E.: 1962,Advanced Engineering Mathematics, Wiley and Sons.Google Scholar
- Rubinow, S. I. and Keller, J. B.: 1961, ‘The Transverse Force on a Spinning Sphere Moving in a Viscous Fluid’,J. Fluid Mech. 11, 447–459.Google Scholar
- Saffman, P. G.: 1965, ‘The Lift on a Small Sphere in a Slow Shear Flow’,J. Fluid Mech. 22, 385–440.Google Scholar
- Tchen, C. M.: 1947, ‘Mean Value and Correlation Problems Connected with the Motion of Small Particles Suspended in a Turbulent Fluid’, Ph. D. Thesis, Delft.Google Scholar
- Warner, J.: 1969, ‘The Microstructure of Cumulus Cloud. Part II: The Effect On Droplet Size Distribution of Cloud Nucleus Spectrum and Updraft Velocity’,J. Atmos. Sci. 26, 1272–1282.Google Scholar
- Warner, J.: 1970, ‘The Microstructure of Cumulus Cloud. Part III: The Nature of the Updraft’,J. Atmos. Sci. 27, 682–688.Google Scholar