Thermal Simulation in Powder Bed Fusion (PBF)#
Mathematical Model:
\[\begin{split}
\begin{align*}
&\text{Heat Conduction:} \quad \rho c \frac{\partial T}{\partial t} - \nabla \cdot (k \nabla T) = Q \\
&\text{Melting and Solidification:} \quad \rho_l L \frac{\partial \phi}{\partial t} = H \nabla \cdot \left(\frac{\nabla T}{\lVert \nabla T \rVert}\right)
\end{align*}
\end{split}\]
Weak Formulation:
\[\begin{split}
\begin{align*}
&\int_{\Omega} \left(\rho c \frac{\partial T}{\partial t} \phi + k \nabla T \cdot \nabla \phi - Q \phi\right) \,d\Omega = 0 \\
&\int_{\Omega} \left(\rho_l L \frac{\partial \phi}{\partial t} - H \nabla \cdot \left(\frac{\nabla T}{\lVert \nabla T \rVert}\right) \phi\right) \,d\Omega = 0
\end{align*}
\end{split}\]