Radially Locked Sun-Ray Patterns in Reaction-Diffusion-Advection Systems

Area of Science:

• Chemical kinetics
• Fluid dynamics
• Pattern formation

Background:

• Traveling fronts are common in natural systems and prone to instabilities.
• Diffusive and convective instabilities can cause transverse cellular deformations in fronts.
• Radial advection can lock fronts, influencing their stability and pattern evolution.

Purpose of the Study:

• To investigate the formation of new patterns in traveling fronts when destabilization is triggered around a radially locked front.
• To theoretically and experimentally demonstrate the development of angularly shifting, sun-ray-like patterns.
• To analyze the control parameters influencing these novel structures.

Main Methods:

• Theoretical analysis using linear stability analysis.
• Numerical simulations including nonlinear simulations.
• Experimental investigation using the chlorite-tetrathionate reaction.

Main Results:

• Angularly shifting sun-ray-like patterns emerge around autocatalytic fronts stabilized by radial advection.
• These patterns originate from a diffusive instability driven by disparate diffusion rates of autocatalyst X and reactant Y.
• The characteristics of the observed shining-star structures are tunable via flow rate (Q) and diffusion coefficient ratio (δ).

Conclusions:

• Radial advection can stabilize traveling fronts and lead to the formation of unique spatiotemporal patterns.
• The interplay between diffusion rates and advection is crucial for pattern selection and control.
• The chlorite-tetrathionate reaction serves as a model system for studying these advection-driven pattern formations.