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Turbulent breakage of ductile aggregates

Cristian Marchioli* and Alfredo Soldati

  • Dipartimento di Ingegneria Elettrica, Gestionale e Meccanica, Università di Udine, Udine, Italy and Dipartimento di Fluidodinamica, CISM, Udine, Italy

  • *Corresponding author: marchioli@uniud.it
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Phys. Rev. E 91, 053003 – Published 5 May, 2015

DOI: https://doi.org/10.1103/PhysRevE.91.053003

Abstract

In this paper we study breakage rate statistics of small colloidal aggregates in nonhomogeneous anisotropic turbulence. We use pseudospectral direct numerical simulation of turbulent channel flow and Lagrangian tracking to follow the motion of the aggregates, modeled as sub-Kolmogorov massless particles. We focus specifically on the effects produced by ductile rupture: This rupture is initially activated when fluctuating hydrodynamic stresses exceed a critical value, σ>σcr, and is brought to completion when the energy absorbed by the aggregate meets the critical breakage value. We show that ductile rupture breakage rates are significantly reduced with respect to the case of instantaneous brittle rupture (i.e., breakage occurs as soon as σ>σcr). These discrepancies are due to the different energy values at play as well as to the statistical features of energy distribution in the anisotropic turbulence case examined.

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Outline

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Phys. Rev. E 91, 053003– Published 5 May, 2015
  • Received 6 January 2015

©2015 American Physical Society

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