Influence of interatomic bonding potentials on detonation properties.

Area of Science:

• Computational materials science
• Chemical kinetics
• Shock physics

Background:

• Macroscopic detonation properties are crucial for energetic materials.
• Understanding the link between molecular properties and bulk behavior is essential for material design.

Purpose of the Study:

• Investigate the dependence of detonation velocity, reaction zone thickness, and critical width on molecular exothermicity (Q) and dissociation energy (D(e)(AB)).
• Characterize the shock-induced response and detonation behavior of a 2D diatomic molecular system.

Main Methods:

• Utilized molecular dynamics (MD) simulations with a reactive empirical bond-order potential.
• Performed nonequilibrium MD simulations to study shock response and equilibrium MD simulations to determine Chapman-Jouguet (CJ) states.
• Analyzed radial distribution functions to characterize atomic structure.

Main Results:

• Discovered a linear dependence between the square of detonation velocity and both Q and D(e)(AB).
• Detonation velocities align with the Chapman-Jouguet (CJ) model, influenced by product/reactant equations of state.
• Identified unusual polyatomic clusters near CJ conditions and determined minimum Q and maximum D(e)(AB) for sustained detonation.

Conclusions:

• Molecular properties significantly govern macroscopic detonation characteristics in diatomic molecular systems.
• The Zeldovich-von Neumann-Döring model describes the reaction zone structure.
• Detonation failure diameter is also dependent on Q and D(e)(AB), explainable by reaction zone properties.