Jutzi 2008 1D P-alpha Compaction Wave Validation

Overview

This case reproduces the 1D porous aluminum compaction wave test from Jutzi et al. (2008) Section 5.1, comparing the following physical quantities at a fixed time against the paper’s SPH curves and the analytical solution:

• Pressure distribution
• Distension alpha distribution

This type of test is used to examine the performance of the p-alpha model in terms of wave front structure, compaction zone thickness, and post-wave compaction degree.

This run used shock_00350.h5 as the reference frame. Extracted results:

• Material 0 particle count: 400
• Pressure range: ~1.07e-01 Pa to 5.07e+09 Pa
• Distension range: 1.0 to 1.275

The compaction wave has driven the material from the initial porous state to a nearly fully compacted region.

Validation Objective

The physical picture of this case: a right-side moving piston drives a compaction wave through an initially porous aluminum rod. As the wave propagates forward, the material transitions from an initial distension of

toward a denser state.

How to Run

Test directory:

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GASPHiA-Tests/Jutzi2008_Section5_1_PAlphaCompactionWave

Run with:

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./run_all.sh --source-dir /path/to/GASPHiA --cuda 0

The default workflow executes sequentially:

1. Compile and run input/gen_input_1d.cpp
2. Compile GASPHiA using the local para.cuh
3. Run compaction_wave.ini
4. Read output/shock_00350.h5
5. Output pressure / distension comparison plots

Note: this case’s para.cuh reserves a macro specifically for reproducing the experimental path:

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#define JUTZI2008_5_1_reproduce_need 1

Result Interpretation

The figure is divided into two panels:

• Top: Pressure profile
• Bottom: Distension alpha profile

Each panel simultaneously plots three curves:

• GASPHiA computed results
• Paper SPH curve
• Analytical reference curve

Actual Run Data

Key metrics extracted from post-processing:

These values validate the simulation from two perspectives:

On the one hand, the output alpha covers the entire range from the initial porous state to the fully compacted state. On the other hand, the peak pressure has entered the GPa range, indicating that the compaction wave is sufficiently strong and has formed a genuine compaction structure.