Modeling the formation of sedan crater using the FLAG and HOSS codes

Area of Science:

• Geophysics
• Computational Science
• Engineering

Background:

• Explosion crater formation involves complex physics, requiring numerical modeling for understanding.
• Validation of these models necessitates experimental data, which is often limited.
• Both continuum and discrete element models have advantages and disadvantages for simulating these events.

Purpose of the Study:

• To model the formation of the Sedan crater, a large human-made crater.
• To compare the effectiveness of arbitrary Lagrangian-Eulerian (ALE) hydrocode and finite discrete element method (FDEM) approaches.
• To demonstrate how combining multiple numerical methods enhances understanding of complex physical processes with limited data.

Main Methods:

• Utilized an arbitrary Lagrangian-Eulerian (ALE) hydrocode for early-time continuum fluid behavior.
• Employed a finite discrete element method (FDEM) for later-time solid mechanics and material settlement.
• Applied both methods to simulate the Sedan crater formation from an underground nuclear detonation.

Main Results:

• The ALE hydrocode accurately modeled early-time behavior before mound rupture and fireball venting.
• The FDEM approach effectively reproduced the final crater dimensions after material settlement.
• The study highlights the distinct strengths of each method in different temporal and physical regimes.

Conclusions:

• Leveraging both continuum hydrodynamics and discrete element methods provides a more comprehensive understanding of explosion crater formation.
• This hybrid approach is particularly valuable for complex problems with scarce experimental data.
• Different numerical methods are best suited for different physical regimes within the cratering process.