Particle dispersion in forced isotropic low-Mach-number turbulence

Dispersion of solid particles in forced isotropic low-Mach-number turbulent flows is studied. The carrier phase is considered in the Eulerian frame an d is simulated by direct numerical simulation (DNS) whereas the particles a re treated in a Lagrangian context. The formulation includes the effects of the two-way coupling on the carrier phase. The results verify previous obs ervations for velocity field in similar studies in incompressible flows whi le providing new insights into the modifications of the thermodynamic field s. It is found that the ratio of the root mean square (rms) Mach number to the mean Mach number is nearly constant (similar to 0.41) for all of the ca ses. A peak value is observed in the variation of the particle velocity var iance (normalized with the fluid velocity variance) with the mass loading r atio. The polytropic coefficient decreases linearly by the increase of the mass loading ratio, and nonlinearly by the decrease of the particle time co nstant. (C) 1999 Elsevier Science Ltd. All rights reserved.