CFD_HE
CFD
"Optional title"
sid
type, gid, follow
$\rho$, $A$, $B$, $R_1$, $R_2$, $\omega$, $e_0$, $D$
$e_{ab}$, $t_{ab}$
Parameter definition
Description
This command is used to fill a region of the CFD_DOMAIN with a high explosive. Explosives can be detonated using CFD_DETONATION. The pressure is defined as:
$\displaystyle{ p = A \left( 1 - \frac{\omega}{R_1 V} \right) \mathrm{e}^{-R_1 V} + B \left( 1 - \frac{\omega}{R_2 V} \right) \mathrm{e}^{-R_2 V} + \omega e}$
where $V$ is the ratio of current density to initial density and $e$ is the current internal energy per unit volume. The remaining afterburn energy at coordinate $\mathbf{x}$ evolves according to:
$\displaystyle{ \frac{\partial \dot{e}_{ab}}{\partial t} (\mathbf{x},t) = -\frac{e_{ab}(\mathbf{x},t)}{t_{ab}} }$
The follow option is used when switching between a FE formulation for the undetonated explosive and a CFD formulation from detonation time and onwards. This is typically done by syncronizing the deactivation of elements (ACTIVATE_ELEMENTS) and the detonation (CFD_DETONATION).
Input parameters used for the presets are presented on our website (Support > Documentation > Verification – Calibrated Explosives).