S. Yuu et al., Numerical simulation of the high Reynolds number slit nozzle gas-particle jet using subgrid-scale coupling large eddy simulation, CHEM ENG SC, 56(14), 2001, pp. 4293-4307
Large eddy simulation (LES) model in which the effect of the particle exist
ence on subgrid-scale flows have been taken into account is proposed. The k
inetic energy of the subgrid-scale flow to obtain a turbulent viscosity coe
fficient of the subgrid-scale flow in the LES has been calculated in assumi
ng that the interaction terms between the gas and particles, the turbulent
production term and the viscous dissipation term were balanced with each ot
her in the kinetic energy equation of the subgrid-scale turbulent flow. Usi
ng this model, three-dimensional Navier-Stokes equations and the Lagrangian
particle motion equations are simultaneously solved to describe the high R
eynolds number (Re = 10(4)) gas-particle jet flow and the effect of particl
e existence on it. The calculated results of air and particle turbulent cha
racteristics which are mean velocity, turbulent intensity and Reynolds stre
ss distributions are in good agreement with experimental data measured by a
laser Doppler velocimeter.
The existence of particles usually reduces the grid-scale turbulence in the
high Reynolds number developed turbulent jet. On the other hand, the parti
cle existence which is some kind of flow disturbance produces grid-scale fl
uctuations in the initial and the transitional regions of the jet and then
it increases the air turbulent intensity. When particle size is much smalle
r than the grid size, the particle existence reduces the subgrid-scale turb
ulence. However, when the product of the particle relative velocity and the
particle concentration gradient is very large, the particle existence is a
ble to increase the subgrid-scale turbulence. (C) 2001 Published by Elsevie
r Science Ltd.