Simulation of species concentration distribution in reactive flows with unsteady boundary conditions

AUTOR(ES)

Oliveira Filho, A. G. de, Mangiavacchi, N., Pontes, J.

FONTE

Braz. J. Chem. Eng.

DATA DE PUBLICAÇÃO

2017-10

RESUMO

Abstract The determination of species concentration profiles in reactive flows with variable inlets is a problem of practical interest to many fields such as in flow reactor transient operation and in cyclic degradable pollutants disposals in watercourses. In these cases, the inflow condition often consists of a time-dependent function, which may imply unsteady outflows, not always well represented by the usual boundary conditions (BC) used so far. A new approach, using an outlet condition in the form of a material derivative, termed Material Derivative Boundary Condition (MDBC), is introduced and a numerical model to solve convection-diffusion-reaction equations in two-dimensional (2-D) incompressible flows is developed. Upon reviewing the literature, it is noted that the Finite Element Method (FEM) is rarely used in the simulation of reactive flows, in spite of its ability of consistently coping with variable BCs. The above facts are reasons to explore its use along with a semi-discrete formulation with the Galerkin Method in our simulations. Results are obtained for various conditions, in order to show features of the code, and are compared to existing solutions. Use of the MDBC is shown to provide a better approximation of the exit concentrations and use of FEM in reactive flows is further enhanced.

Documentos Relacionados

• Wind tunnel simulation of atmospheric boundary layer flows
• Absorbing boundary conditions for numerical simulation of waves
• The use of molecular spectra simulation for diagnostics of reactive flows
• Numerical simulation of two-dimensional complex flows around bluff bodies using the immersed boundary method
• Recent extensions of the residence time distribution concept: unsteady state conditions and hydrodynamic model developments