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Detonation with finite-rate chemistry• 0.05 meter 1D domain with 1500 cells• 298.15 °K and 1 atmosphere ambient• 0.001 meter driver at 3000° K and 30 atmospheres• Spatially first-order explicit HLLC solver for
fluxes• Sources use implicit 6th order Runge-Kutta
algorithm• Compared to results of CFD++ code
FCT solver with solution adaptive mesh • 10 atmosphere 300 °K cylinder of air expands into
one atmosphere air• Domain: 10 meters x 10 meters with 40 x 40 cells• Two levels of cell refinement in response to
pressure gradients• FCT solver modified to handle cell refinement
Level Set Tracking• Location of shock-, detonation-, or contact front is tracked
using scalar value, G, that is zero at front.
• Value of G in a cell is the signed distance from the front
• Shock or detonation front moves at speed determined by Hugoniot relation
• Contact front moves at flow speed
• Two states are maintained in cells containing front or near to front.
• Front states change in response to edge fluxes and front fluxes
• Spatially second-order explicit HLLC solver
High-pressure gas bubble expands in water (with and without 3 levels of refinement) (tracked contact)
Simulation of explosive blast
(near field to far field) • Domain: 10.9 meters x 5.1 meters with 100 x 140 cells
• Detonation front is tracked with two levels of refinement until solid explosive cylinder is consumed
• Spatially second-order explicit HLLC solver used for explosive products and air
• Trajectory of shock at height of burst matches raw experimental data at mid field and far field
• Simulation produces better estimate of front pressures near burst compared to extrapolated experimental fit to raw experimental data
Detonation of explosive charge mixed with inert metal particles (near field to mid field)
• Expanding sphere of combustion products and particles
• JWL gas equation of state - combustion products
• van der Waals gas equation of state - air
• Dense particle equation of state
• HLLC solver - combustion products and air
• FCT Solver - particles
• Momentum and energy exchange between gas and particle phases
Detonation of liquid explosive mixed with reactive metal particles (near field)
• HOM condensed equation of state - liquid explosive
• HOM gas equation of state - explosive combustion products
• van der Waals gas equation of state - air
• Particle equation of state
• HLLC solver - liquid explosive, combustion products, and air
• FCT solver - particles
• Momentum, mass, and energy exchange between gas and particle phases
Chemical Reactions
• Arrhenius combustion model for nitromethane
• Nitromethane H20 + (CO2-CO)
• Particle-diameter controlled oxidation rate
• Metal+H20 + (CO2-CO)+O2 metal oxides