Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
EFFECT OF THE MACRO-SCALE TOPOLOGY OVER THE EFFECTIVE DRAG COEFFICIENT IN DENSE GAS-SOLID FLUIDIZED FLOWS
Submission Author:
Seyed Reza Amini Niaki , SP , Brazil
Co-Authors:
Seyed Reza Amini Niaki, Joseph Mouallem, Christian Milioli, Fernando Milioli
Presenter: Seyed Reza Amini Niaki
doi://10.26678/ABCM.ENCIT2018.CIT18-0017
Abstract
Large scale simulation of fluidized gas-particle flows with two-fluid modeling requires closure models to deal with sub-grid filtered parameters such as filtered and residual stresses and filtered drag. The very heterogeneous topology of the concerning flows is qualitatively well captured by the current two-fluid formulations, but quantitative accuracy is still out of reach mostly due to the lack of more accurate sub-grid closure models. The effective drag coefficient is one of those closures for which sub-grid modeling requires improvement. Literature presents models for the effective drag coefficient derived from results of highly resolved simulations with two-fluid modeling which disregard any macro-scale impact. In this work it is showed that macro-scale effects cannot be disregarded if higher accuracy is pursued. The macro-scale parameters considered were the domain average solid volume fraction and gas flow Reynolds number, both showing significant effects over the effective drag coefficient. Only dense gas-solid flows were considered, as a complement to a previous work dealing with dilute conditions (Niaki et al., “Effect of the flow Macro-Scale on the effective drag coefficient in Gas-Solid flows”, COBEM2017).
Keywords
gas-particle flow, Fluidization, Two Fluid Model, Sub-grid modeling, effective drag
