Numerical Simulation of Time-Dependent Reacting Flows

JOSÉ P. TAMAGNO; SERGIO A. ELASKAR; GUSTAVO A. RÍOS RODRIGUEZ

Paraná, Entre Ríos

Congreso; MECOM2002 - Primer Congreso Sudamericano de Mecánica Computacional; 2002

Asociación Argentina de Mecánica Computacional (AMCA) y Asociación Brasileña de Mecánica Computacional (ABMEC).

A numerical methodology for solving quasi-one dimensional, time-dependent reacting flowproblems is outlined in this paper. The numerical approach uses a finite-volume Harten-Yee TVD scheme for the Euler equations of motion coupled with finite rate chemistry. Gas interfaces are detected and tracked via a Riemann solver and to reduce the number of nodes without smearing the interfaces, a moving mesh is used. The source terms representing the finite-rate chemical kinetics and vibrational relaxation are often large and make the algorithm too stiff to be advanced explicitly. To avoid this stiffness an implicit treatment of these source terms is implemented. The numerical program can work with 13 chemical reacting species and 33 different reactions of a hydrogen-oxygen-nitrogen combustion mechanism, each of which may proceed forward or backward. Since helium is often employed in certain applications it has also been included, although, it was considered an inert species. Numerical simulations that show the potential of the computer code in predicting flow properties, wave patterns and chemical compositions are presented.