A Lagrangian stochastic model for the deposition of heavy particles from turbulent flows is presented. Heavy particles are treated as tracer particles moving in a virtual fluid having heavy particle velocity statistics. These velocity statistics are deduced from the particle momentum equation. The m
A Lagrangian Stochastic Model for the Dispersion and Deposition of Brownian Particles
β Scribed by Andrew Michael Reynolds
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 104 KB
- Volume
- 217
- Category
- Article
- ISSN
- 0021-9797
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β¦ Synopsis
A Lagrangian stochastic model for the dispersion and deposition of submicron-size particles is formulated and validated. The model satisfies the well-mixed condition, incorporates molecular diffusivity, and accounts for the effects of Reynolds number upon Lagrangian particle statistics. Reynolds number effects are found to be significant in the viscous sublayer and the buffer zone of a turbulent shear flow. The effects are due almost entirely to the change in the Lagrangian integral time scale. Sawford's correction to first-order Lagrangian stochastic models for the effects of Reynolds number is found to be appropriate for inhomogeneous turbulence even when the Taylor-Reynolds number R Ο³ O(0.1). The model predicts, in close accord with experiment and the results of direct numerical simulations, that the nondimensional particle deposition velocity K Ψ β«Ψβ¬ 0.06Sc Ψ2/3 , where Sc is the Schmidt number. When Reynolds number effects are neglected, K Ψ is overpredicted by several orders of magnitude.
π SIMILAR VOLUMES
The modeling approach of B. L. Sawford and F. H. Guest ("8th Symposium of Turbulence and Diffusion; San Diego, CA," pp. 96-99. Am. Meteorol. Soc., Boston, MA, 1990) is extended to encompass the formulation of Lagrangian stochastic models for fluid velocities along heavy-particle trajectories in inho
binding molecules influence the rate of particle attachment, A model is presented for the attachment of a Brownian particle which accounts for both discrete and non-discrete interacto a surface mediated by both the conservative colloidal forces and tions, such as London-van der Waals, electrostatic,