Use of 1-D detonation pressure leads to excellent agreement in phase length experiment and shell simulation

Taylor wave drives oscillation, not von Neumann pressure, already very good agreement, if average pressure is prescribed via appropriate shock

Further work to assess steadiness of detonation in experiment

Next step is to redo strain gauge measurements

Tests towards fully coupled simulations

Treatment of shells/thin structures

Thin boundary structures or lower-dimensional shells require artificial “thickening” to apply ghost fluid method

Unsigned distance level set function

Treat cells with 0<

Leaving unmodified ensures correctness of r

Refinement criterion based on ensures reliable mesh adaptation

Use face normal in shell element to evaluate in p= pu– pl

about ~107 cells required to capture correct wall thickness in fracturing tube experiment with this technique (2-3 ghost cells within wall, uniform spatial discretization)

Coupled simulations for thin shells

Performance of coupled thin shell code

Coupled simulation with standard Euler equations (Roe+MUSCL, dimensional splitting)

AMR base mesh 40x40x80, 2 additional levels with refinement factor 2, ~3,000,000 cells.

Modeled tube thickness 0.0017 mm, (2x thicker than in experiment).

Solid Mesh: ~ 5,000 elements.

Calculation run on 26 fluid CPUs, 6 solid CPUs P4: ~4.5h real time

Conclusions and outlook

Detonation simulation

Fully resolved detonation structure simulations for basic phenomena in 3D possible for smaller detailed reaction systems

Combination of mixed explicit-implicit time-discretization with parallel SAMR and reliable higher order scheme

Cartesian scheme for complex embedded boundaries

Accurate results can be obtained by supplementing GFM with SAMR

With well developed auxiliary algorithms an implicit geometry representation can be highly efficient

Future goal: Extend implementation from diffused boundary method GFM to accurate boundary scheme based on

Fully coupled AMR simulations with fracture using GFM with thin shell technique

Detonation model to propagate three-dimensional Ethylen-Oxygen detonation with CJ velocity

Redo experiments with mixture that allows direct simulation, e.g. Hydrogen-Oxygen

AMROC Scalability

Domain based partitioning creates unnecessary waiting times in AMR algorithm, because single levels are not thoroughly balanced

Scalable AMR requires (R.Rotta, R.Deiterding):

Parallel inter-level operations to allow slight differences in level decomposition

Fast parallel partitioning technique that considers block structure and aims to preserve data locality, but balances single level work almost perfectly