Pulsating wave propagation in reactive flows: flow-distributed oscillations

Area of Science:

• Chemical kinetics
• Nonlinear dynamics
• Fluid dynamics

Background:

• Stationary waves in reactive flows were previously generated using constant inflow concentrations.
• The Belousov-Zhabotinsky reaction is a classic example of a chemical oscillator.

Purpose of the Study:

• To investigate the impact of oscillatory boundary conditions on reactive flow systems.
• To characterize the resulting traveling wave phenomena, including pulsating and steady propagation.

Main Methods:

• Experimental generation of traveling waves in a tubular packed bed reactor under isothermal conditions.
• Numerical simulations of the reaction-diffusion-advection system with a realistic kinetic model.
• Development of a one-variable iterative map to capture the kinematic mechanism.

Main Results:

• Observation of traveling wave fronts propagating in pulsating or steady manners.
• Demonstration that wave pulsation is induced by a kinematic mechanism, not diffusion, due to equal transport coefficients.
• Validation of experimental findings through numerical simulations.

Conclusions:

• Oscillatory boundary conditions can induce complex traveling wave dynamics in reactive flows.
• A kinematic mechanism is sufficient to explain wave pulsation in this system.
• The study provides a simplified model to understand the underlying physics of wave propagation.