Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-26T19:18:43.525Z Has data issue: false hasContentIssue false

Direct simulation of particle dispersion in a decaying isotropic turbulence

Published online by Cambridge University Press:  26 April 2006

S. Elghobashi
Affiliation:
Mechanical and Aerospace Engineering Department, University of California. Irvine, CA 92717, USA
G. C. Truesdell
Affiliation:
Mechanical and Aerospace Engineering Department, University of California. Irvine, CA 92717, USA

Abstract

Dispersion of solid particles in decaying isotropic turbulence is studied numerically. The three-dimensional, time-dependent velocity field of a homogeneous, non-stationary turbulence was computed using the method of direct numerical simulation (DNS). A numerical grid containing 963 points was sufficient to resolve the turbulent motion at the Kolmogorov lengthscale for a range of microscale Reynolds numbers starting from Rλ = 25 and decaying to Rλ = 16. The dispersion characteristics of three different solid particles (corn, copper and glass) injected in the flow, were obtained by integrating the complete equation of particle motion along the instantaneous trajectories of 223 particles for each particle type, and then performing ensemble averaging. The three different particles are those used by Snyder & Lumley (1971), referred to throughout the paper as SL, in their pioneering wind-tunnel experiment. Good agreement was achieved between our DNS results and the measured time development of the mean-square displacement of the particles.

The simulation results also include the time development of the mean-square relative velocity of the particles, the Lagrangian velocity autocorrelation and the turbulent diffusivity of the particles and fluid points. The Lagrangian velocity frequency spectra of the particles and their surrounding fluid, as well as the time development of all the forces acting on one particle are also presented. In order to distinguish between the effects of inertia and gravity on the dispersion statistics we compare the results of simulations made with and without the buoyancy force included in the particle motion equation. A summary of the significant results is provided in §7 of the paper.

The main objective of the paper is to enhance the understanding of the physics of particle dispersion in a simple turbulent flow by examining the simulation results described above and answering the questions of how and why the dispersion statistics of a solid particle differ from those of its corresponding fluid point and surrounding fluid and what influences inertia and gravity have on these statistics.

Type
Research Article
Copyright
© 1992 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Auton, T. R. 1983 The dynamics of bubbles, drops and particles in motion in liquids. PhD thesis, Cambridge University.
Balachandar, S. & Maxey, M. R. 1989 Methods for evaluating fluid velocity in spectral simulations of turbulence. J. Comput. Phys. 115, 15691579.Google Scholar
Basset, A. B. 1888 A Treatise on Hydrodynamics, vol. 2, p. 285. Dover.
Batchelor, G. K. 1949 Diffusion in a field of homogeneous turbulence.. Austal. J. Sci. Res. A 2, 437450.Google Scholar
Batchelor, G. K. 1953 The Theory of Homogeneous Turbulence. Cambridge University Press.
Boussinesq, J. 1903 Theorie Analytique de la Chaleur, vol. 2, p. 224. Paris.
Corrsin, S. & Lumley, J. L. 1956 On the equation of motion for a particle in turbulent fluid. Appl. Sci. Res. 6, 114116.Google Scholar
Crowe, C. T., Chung, J. N. & Trout, T. R. 1988 Particle mixing in free shear flows. Prog. Energy Combust. Sci. 14, 171194.Google Scholar
Csanady, G. T. 1963 Turbulent diffusion of heavy particles in the atmosphere. J. Atmos. Sci. 20, 201208.Google Scholar
Elghobashi, S. E. & Truesdell, G. C. 1989a Direct simulation of particle dispersion in grid turbulence and homogeneous shear flows. Bull. Am. Phys. Soc. 34, 2311.Google Scholar
Elghobashi, S. E. & Truesdell, G. C. 1989b Direct simulation of particle dispersion in a decaying isotropic turbulence. Seventh Symp. on Turbulent Shear Flows, M, pp. 121122.
Elghobashi, S. E. & Truesdell, G. C. 1991 On the interaction between solid particles and decaying turbulence. Eighth Symp. on Turbulent Shear Flows, vol. 1, pp. 731736.
Gerz, T., Schumann, U. & Elghobashi, S. E. 1989 Direct simulation of stably stratified homogeneous turbulent shear flows. J. Fluid Mech. 200, 563594.Google Scholar
Kaneda, Y. & Gotoh, T. 1991 Lagrangian velocity autocorrelation in isotropic turbulence.. Phys. Fluids A 3, 19241933.Google Scholar
Kraichnan, R. H. 1970 Diffusion by a random velocity field. Phys. Fluids 13, 2231.Google Scholar
Lumley, J. L. 1957 Some problems connected with the motion of small particles in a turbulent fluid. PhD thesis, Johns Hopkins University: 41.
Lumley, J. L. 1978 Two-phase and non-newtonian flows. Topics Phys. 12, 290324.Google Scholar
Mclaughlin, J. B. 1989 Aerosol particle deposition in numerically simulated channel flow.. Phys. Fluids A 1, 12111224.Google Scholar
Maxey, M. R. & Riley, J. J. 1983 Equation of motion for a small rigid sphere in a nonuniform flow. Phys. Fluids 26, 883889.Google Scholar
Mohamed, M. S. & LaRue, J. C. 1990 The decay power-law in grid generated turbulence. J. Fluid Mech. 219, 195214.Google Scholar
Monin, A. S. & Yaglom, A. M. 1979 Statistical Fluid Mechanics, vol. 1, pp. 540550. The MIT Press.
Orszag, S. A. & Patterson, G. S. 1972 Numerical simulation of three-dimensional homogeneous turbulence. Phys. Rev. Lett. 28, 7679.Google Scholar
Oseen, C. W. 1927 Über die stokes'sche formel, und über eine verwandte aufgabe in der hydrodynamik. Hydromechanik 82, Leipzig.Google Scholar
Pao, Y.-H. 1965 Structure of turbulent velocity and scalar fields at large wavenumbers. Phys. Fluids 8, 10631075.Google Scholar
Reeks, M. W. 1977 On the dispersion of small particles suspended in an isotropic turbulent fluid. J. Fluid Mech. 83, 529546.Google Scholar
Riley, J. J. & Patterson, G. S. 1974 Diffusion experiments with numerically integrated isotropic turbulence. Phys. Fluids 17, 292297.Google Scholar
Schumann, U. 1977 Realizability of Reynolds-stress turbulence models. Phys. Fluids 20, 721725.Google Scholar
Schumann, U. & Patterson, G. S. 1978 Numerical study of pressure and velocity fluctuation in nearly isotropic turbulence. J. Fluid Mech. 88, 685709.Google Scholar
Shlien, D. J. & Corrsin, S. 1974 A measurement of Lagrangian velocity autocorrelation in approximately isotropic turbulence. J. Fluid Mech. 62, 255271.Google Scholar
Snyder, W. H. & Lumley, J. L. 1971 Some measurements of particle velocity autocorrelation functions in a turbulent flow. J. Fluid Mech. 48, 41.Google Scholar
Squires, K. D. & Eaton, J. K. 1991 Measurements of particle dispersion obtained from direct numerical simulations of isotropic turbulence. J. Fluid Mech. 226, 135.Google Scholar
Stokes, G. C. 1851 On the effect of the internal friction of fluids on the motion of pendulums. Trans. Camb. Phil. Soc. 9, 8.Google Scholar
Taylor, G. I. 1921 Diffusion by continuous movement.. Proc. Lond. Math. Soc. A 20, 196212.Google Scholar
Tchen, C. M. 1947 Mean value and correlation problems connected with the motion of small particles suspended in a turbulent fluid. PhD thesis, Delft University. The Hague: Martinus Nijhoff.
Tennekes, H. & Lumley, J. L. 1972 A First Course in Turbulence. The MIT Press.
Townsend, A. A. 1976 The Structure of Turbulent Shear Flow, p. 340. Cambridge University Press.
Truesdell, G. C. 1989 A study of two-dimensional interpolation schemes. Rep. no. FTS/89-1, Mechanical Engineering Department, University of California, Irvine.
Wells, M. R. & Stock, D. E. 1983 The effects of crossing trajectories on the dispersion of particles in a turbulent flow. J. Fluid Mech. 136, 3162.Google Scholar
Yeung, P. K. & Pope, S. B. 1988 An algorithm for tracking fluid particles in numerical simulations of homogeneous turbulence. J. Comp. Phys. 79, 373415.Google Scholar
Yudine, M. I. 1959 Physical considerations on heavy-particle diffusion. Adv. Geophys. 6, 185191.Google Scholar