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PARTICLE_HE

Particle

*PARTICLE_HE
"Optional title"
sid, $N_p^{sid}$
type, gid, follow, $dsf$, -, -, -, $t_{end}$
$\rho_0$, $e_0$, $\gamma$, $v$, $D$

Parameter definition

Variable
Description
sid
Subdomain ID
$N_p^{sid}$
Number of particles
default: not used
type
High explosive type
options:
preset $\rightarrow$ see list below
user $\rightarrow$ user defined
gid
Geometry ID
follow
Force particles to follow overlapping elements
options:
0 $\rightarrow$ no
1 $\rightarrow$ yes
$dsf$
Particle density scale factor (particles per unit volume)
default: 1
-
Reserved
-
Reserved
-
Reserved
$t_{end}$
Particle deactivation time or FUNCTION (fcn)
options: time or fcn
default: not used
$\rho_0$
Density (this line is only used if type=USER)
$e_0$
Energy per unit volume
$\gamma$
Fraction between C${}_\mathrm{p}$ and C${}_\mathrm{v}$ at zero co-volume (ideal gas regime)
$v$
Co-volume at $\rho = \rho_0$
$D$
Detonation velocity

Description

Discrete particle high explosive domain definition.

The subdomain ID (sid) determines in which order particles are filled into the global domain. In case subdomains are overlapping, the domain with the largest ID will overwrite (remove) particles belonging to domains with lower domain ID's.

Parameter type can be specified as a preset or a user defined explosive. The input parameters used for the presets are presented on our website (Support > Verifier documentation > Verification of explosives).

Available presets:

$\begin{array}{ll} \textsf{ANFO} & \textsf{(Ammonium nitrate fuel oil)} \\ \textsf{C4} & \textsf{(Composition C-4)} \\ \textsf{COMPA} & \textsf{(Composition A-3)} \\ \textsf{COMPB} & \textsf{(Composition B, grade A)} \\ \textsf{HMX} & \\ \textsf{LX-10-1} & \\ \textsf{LX-14-0} & \\ \textsf{M46} & \\ \textsf{MCX-6100} & \\ \textsf{NSP-711} & \\ \textsf{OCTOL} & \textsf{(Octol 78/22)} \\ \textsf{PBXN-110} & \\ \textsf{PBXN-9010} & \\ \textsf{PETN} & \\ \textsf{TETRYL} & \\ \textsf{TNT} & \\ \end{array} $

The follow flag can be used when gid is a GEOMETRY_PART. Setting follow=1 forces the particles to follow the motion of the finite elements (where they are embedded). Note that the elements and the particles represent the same material. Elements are active prior to erosion and the particles are active after erosion. This feature is typically used to model undetonated explosive material with Finite Elements. At detonation the elements are eroded (e.g. ACTIVATE_ELEMENTS) and replaced by the particles.

$1 \lt \gamma \leq 5/3$ determines the ratio $\xi$ between thermal translational energy and molecular spin + vibrational energy.

$\displaystyle{ \xi = \frac{3}{2}(\gamma - 1) }$

$N_p^{sid}$ is optional. If not defined, then this sub-id will use a fraction of the the particles $N_p$ defined in PARTICLE_DOMAIN.

Example

High explosive defined by preset and user

This example demonstrates the different options for parameter type. The model consists of two cylindrical TNT charges. The first PARTICLE_HE command uses the preset and the second command uses a user defined explosive. The data specified in the user defined explosive is identical to the data used in the preset.

*PARAMETER tend = 5e-5, "Termination time" R = 0.02, "HE charge radius" L = 0.25, "HE charge length" D = 0.25, "Distance between HE charges" L_dp = 1.0 , "DP domain size parameter" N_dp = 4e5 , "Number of DP" *UNIT_SYSTEM SI *TIME %tend # # --- DP --- # *PARTICLE_DOMAIN ALL, 0, %N_dp -%L_dp/2, -%L_dp/4, -%L_dp/6, %L_dp/2, %L_dp/4, %L_dp/6 0, 0, 0, 0, 0, 0 # *PARTICLE_HE "Type specified as a preset" 1 TNT, 1 *PARTICLE_HE "Type specified as user" 2 USER, 2 1630, 7.0e9, 1.299, 0.315, 6930 # *PARTICLE_DETONATION "Preset" 1 -%L/2, %D/2, 0 *PARTICLE_DETONATION "User" 2 -%L/2, -%D/2, 0 # # --- GEOMETRIES --- # *GEOMETRY_PIPE "Preset" 1 -%L/2, -%D/2, 0, %L/2, -%D/2, 0, %R *GEOMETRY_PIPE "User" 2 -%L/2, %D/2, 0, %L/2, %D/2, 0, %R # # --- SENSORS --- # *OUTPUT_SENSOR "Preset" 1, DP, -%L/4, -%D/2, 0, %R/2 *OUTPUT_SENSOR "User" 2, DP, -%L/4, %D/2, 0, %R/2 *END