Effect of Turbulence Internal Structure on Diffusion of Heavy Inertial Particles

• Main Authors: I. V. Derevich, A. Iu. Fokina
• Format: Article
• Language: Russian
• Published: MGTU im. N.È. Baumana 2015-01-01
• Series: Matematika i Matematičeskoe Modelirovanie
• Subjects: turbulence; dispersed flow; turbulence spectra; particles inertia; Lagrange correlation; Euler correlation; von Karman turbulence spectrum
• Online Access: http://mathm.elpub.ru/jour/article/view/16

Based on the spectral expansion of Euler correlation of the carrier medium the a closed system of functional equations for the Lagrange spectra of heavy inertial particles and the velocity fluctuations of the carrier medium on the particle trajectory have been obtained. To split the fourth moments the approximation of quasinormality and velocity fluctuations of particles is performed by a random Gaussian process. The approximate self-consistent method is proposed for solving the resulting system of functional equations. The influence of the particle inertia, the velocity of the averaged slip and microstructure of velocity fluctuations of the medium on the parameters of the chaotic motion of an impurity has been studied. It is shown that the difference in integral time scales of Eulerian and Lagrangian correlations is associated with the spatial microstructure of velocity fluctuations of the medium. It is established that in the absence of mass forces, the coefficient of the stationary diffusion of inertial particles is always greater than the diffusion coefficient of inertialess impurity. The dependence of the turbulent diffusion coefficient of particles impurity on the structural parameter of turbulence has been illustrated. The spectrum of Euler correlations of medium velocity fluctuations is modeled by Karman distributions. The influence of the particle inertia, the velocity of the averaged slip and microstructure of velocity fluctuations of the medium on the parameters of the chaotic motion of an impurity has been studied. It is shown that the difference in integral time scales of Eulerian and Lagrangian correlations is associated with the spatial microstructure of velocity fluctuations of the medium. It is established that in the absence of mass forces, the coefficient of the stationary diffusion of inertial particles is always larger than the diffusion coefficient of inertialess impurity. The dependence of the turbulent diffusion coefficient of particles impurity on the structural parameter of turbulence has been illustrated.