Dissipative particle dynamics with reactions: Application to RDX decomposition

Area of Science:

• Computational chemistry
• Materials science
• Chemical engineering

Background:

• Dissipative Particle Dynamics (DPD) is a mesoscopic simulation method.
• Modeling chemical reactions within DPD simulations presents challenges.

Purpose of the Study:

• To introduce a flexible framework for a constant-energy variant of DPD that incorporates chemical reactions (DPD-RX).
• To demonstrate the DPD-RX method for simulating the decomposition of energetic materials.

Main Methods:

• Assigning reaction progress variables to each particle to monitor reaction extent.
• Modeling complex or reduced reaction mechanisms and kinetics within particles.
• Investigating the effects of spatially averaged particle internal temperature and local reaction volume terms.

Main Results:

• Successfully simulated the unimolecular decomposition of cyclotrimethylene trinitramine (RDX).
• Demonstrated implicit mechanisms for capturing condensed phase reactivity.
• Analyzed the expansion dynamics of the product gas mixture.

Conclusions:

• The DPD-RX framework provides a general and flexible approach for simulating reactive systems at the mesoscopic level.
• The method effectively captures condensed phase reactivity and product gas expansion.
• DPD-RX has potential for broader applications in materials science and chemical engineering.