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\subsection{Level Set Method} |
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\subsection{Solution Method} |
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\subsection{Functions} |
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\begin{classdesc}{LevelSet}{domain, func, reinit\_max, reinit\_each, tolerance, smooth} |
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opens the LevelSet \index{Level Set} on the \Domain domain. \var{func} defines the initial Level Set function representing the interface between two fluids. \var{reinit\_max} sets the maximum number of interations to satisfy the normal condition, $|\nabla \phi|=1$, during the reinitilization of the Level Set function. \var{reinit\_each} sets the frequency of reinitialization for a number of time-steps. \var{tolerance} sets the convergence tolerance of the error to satisfy the normal condition during the reinitilization of the Level Set function. \var{smooth} sets the bandwidth of size 2$\alpha h$ along the interface to smooth the physical parameters of density and viscosity; $h$ is the size of the elements in the mesh and $\alpha$ is the smoothing parameter, usually set to 1. |
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\end{classdesc} |
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\begin{methoddesc}[LevelSet]{update\_parameter}{par1, par2} |
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updates the physical parameters using the sign of $\phi$. \var{par1} and \var{par2} are the physical parameter values for the two different fluids, for example, the densities of the two fluids. Usually this method is called twice during each time-step to update the density and viscosity of the two fluids. |
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\end{methoddesc} |
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\begin{methoddesc}[LevelSet]{update\_phi}{vel, dt, t\_step} |
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updates the Level Set function. It performs the advection and reinitialization procedures. \var{vel} is the velocity field of the fluids, \var{dt} is the time-step size, and \var{t\_step} is the current time-step to determine when to reinitialize. |
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\end{methoddesc} |
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%\begin{methoddesc}[LevelSet]{update}{\optional{f=Data(), \optional{fixed_u_mask=Data(), \optional{eta=1, \optional{surface_stress=Data(), \optional{stress=Data()}}}}}} |
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%\begin{methoddesc}[StokesProblemCartesian]{update\_phi}{v,p, |
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%\optional{max_iter=20, \optional{verbose=False, \optional{useUzawa=True}}}} |
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%solves the problem and return approximations for velocity and pressure. |
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%The arguments \var{v} and \var{p} define initial guess. The values of \var{v} marked |
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%by \var{fixed_u_mask} remain unchanged. |
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%If \var{useUzawa} is set to \True |
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%the Uzawa\index{Uszwa} scheme is used. Otherwise the problem is solved in coupled form. In most cases |
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%the Uzawa scheme is more efficient. |
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%\var{max_iter} defines the maximum number of iteration steps. |
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%If \var{verbose} is set to \True informations on the progress of of the solver are printed. |
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%\end{methoddesc} |