Artículo de revista
Influence of particle mass fraction over the turbulent behaviour of an incompressible particle-laden flow
Fecha
2021-10-21Registro en:
23115521
Universidad Autónoma de Occidente
Repositorio Educativo Digital
Autor
Duque-Daza, Carlos
Ramírez-Pastran, Jesús
Lain, Santiago
Institución
Resumen
The presence of spherical solid particles immersed in an incompressible turbulent flow was
numerically investigated from the perspective of the particle mass fraction (PMF or φm), a measure
of the particle-to-fluid mass ratio. Although a number of different changes have been reported to
be obtained by the presence of solid particles in incompressible turbulent flows, the present study
reports the findings of varying φm in the the turbulent behaviour of the flow, including aspects
such as: turbulent statistics, skin-friction coefficient, and the general dynamics of a particle-laden
flow. For this purpose, a particle-laden turbulent channel flow transporting solid particles at three
different friction Reynolds numbers, namely Reτ = 180, 365, and 950, with a fixed particle volume
fraction of φv = 10−3
, was employed as conceptual flow model and simulated using large eddy
simulations. The value adopted for φv allowed the use of a two-way coupling approach between
the particles and the flow or carrier phase. Three different values of φm were explored in this work
φm ≈ 1, 2.96, and 12.4. Assessment of the effect of φm was performed by examining changes of mean
velocity profiles, velocity fluctuation profiles, and a number of other relevant turbulence statistics.
Our results show that attenuation of turbulence activity of the carrier phase is attained, and that such
attenuation increases with φm at fixed Reynolds numbers and φv. For the smallest Reynolds number
case considered, flows carrying particles with higher φm exhibited lower energy requirements to
sustain constant fluid mass flow rate conditions. By examining the flow velocity field, as well as
instantaneous velocity components contours, it is shown that the attenuation acts even on the largest
scales of the flow dynamics, and not only at the smaller levels. These findings reinforce the concept
of a selective stabilising effect induced by the solid particles, particularly enhanced by high values
of φm, which could eventually be exploited for improvement of energetic efficiency of piping or
equivalent particles transport systems