Time Integration and Postprocessing

Classes
class	ryujin::EquationDispatch
class	ryujin::Restart
class	ryujin::Correction
class	ryujin::Postprocessor< Description, dim, Number >
class	ryujin::Quantities< Description, dim, Number >
class	ryujin::TimeIntegrator< Description, dim, Number >
class	ryujin::TimeLoop< Description, dim, Number >
class	ryujin::VTUOutput< Description, dim, Number >

Enumerations
enum class	ryujin::CFLRecoveryStrategy { ryujin::CFLRecoveryStrategy::none , ryujin::CFLRecoveryStrategy::bang_bang_control , ryujin::CFLRecoveryStrategy::cruise_control }
enum class	ryujin::TimeSteppingScheme {   ryujin::TimeSteppingScheme::ssprk_22 , ryujin::TimeSteppingScheme::ssprk_33 , ryujin::TimeSteppingScheme::erk_11 , ryujin::TimeSteppingScheme::erk_22 ,   ryujin::TimeSteppingScheme::erk_33 , ryujin::TimeSteppingScheme::erk_43 , ryujin::TimeSteppingScheme::erk_54 , ryujin::TimeSteppingScheme::strang_ssprk_33_cn ,   ryujin::TimeSteppingScheme::strang_erk_33_cn , ryujin::TimeSteppingScheme::strang_erk_43_cn , ryujin::TimeSteppingScheme::imex_11 , ryujin::TimeSteppingScheme::imex_22 ,   ryujin::TimeSteppingScheme::imex_33 }

Detailed Description

This module contains classes and functions used for timestepping and running the program.

Enumeration Type Documentation

CFLRecoveryStrategy

enum class ryujin::CFLRecoveryStrategy

strong

Controls the chosen invariant domain / CFL recovery strategy.

Enumerator
none	Step with the chosen "cfl max" value and do nothing in case an invariant domain and or CFL condition violation is detected.
bang_bang_control	Step with the chosen "cfl max" value and, in case an invariant domain or "CFL condition" violation is detected, the time step is repeated with "cfl min". If this is unsuccessful as well, a warning is emitted.
cruise_control	Adaptive strategy that similarly to "bang bang control" first steps with the chosen "cfl max" value, and, in case of an invariant domain violation or a "CFL condition" violation restarts the time step using a tau_max hint coming from the sub step where we encountered a problem. This is the default strategy.

Definition at line 26 of file time_integrator.h.

TimeSteppingScheme

enum class ryujin::TimeSteppingScheme

strong

Controls the chosen time-stepping scheme.

Enumerator
ssprk_22	The strong stability preserving Runge Kutta method of order 2, SSPRK(2,2;1/2), with the following butcher tableau \begin{align*} \begin{array}{c|ccc} 0 & 0 \\ \tfrac{1}{2} & \tfrac{1}{2} & 0 \\ \hline 1 & 1 & 0 \end{array} \end{align*}
ssprk_33	The strong stability preserving Runge Kutta method of order 3, SSPRK(3,3;1/3), with the following butcher tableau \begin{align*} \begin{array}{c|ccc} 0 & 0 \\ 1 & 1 & 0 \\ \tfrac{1}{2} & \tfrac{1}{4} & \tfrac{1}{4} & 0\\ \hline 1 & \tfrac{1}{6} & \tfrac{1}{6} & \tfrac{2}{3} \end{array} \end{align*}
erk_11	The explicit Runge-Kutta method RK(1,1;1), aka a simple, forward Euler step.
erk_22	The explicit Runge-Kutta method RK(2,2;1) with the butcher tableau \begin{align*} \begin{array}{c|ccc} 0 & 0 \\ \tfrac{1}{2} & \tfrac{1}{2} & 0 \\ \hline 1 & 0 & 1 \end{array} \end{align*}
erk_33	The explicit Runge-Kutta method RK(3,3;1) with the butcher tableau \begin{align*} \begin{array}{c|ccc} 0 & 0 \\ \tfrac{1}{3} & \tfrac{1}{3} & 0 \\ \tfrac{2}{3} & 0 & \tfrac{2}{3} & 0 \\ \hline 1 & \tfrac{1}{4} & 0 & \tfrac{3}{4} \end{array} \end{align*}
erk_43	The explicit Runge-Kutta method RK(4,3;1) with the butcher tableau \begin{align*} \begin{array}{c|ccc} 0 & 0 \\ \tfrac{1}{4} & \tfrac{1}{4} & 0 \\ \tfrac{1}{2} & 0 & \tfrac{1}{2} & 0 \\ \tfrac{3}{4} & 0 & \tfrac{1}{4} & \tfrac{1}{2} & 0 \\ \hline 1 & 0 & \tfrac{2}{3} & -\tfrac{1}{3} & \tfrac{2}{3} \end{array} \end{align*}
erk_54	The explicit Runge-Kutta method RK(5,4;1) with the butcher tableau TODO
strang_ssprk_33_cn	A Strang split using ssprk 33 for the hyperbolic subproblem and Crank-Nicolson for the parabolic subproblem
strang_erk_33_cn	A Strang split using erk 33 for the hyperbolic subproblem and Crank-Nicolson for the parabolic subproblem
strang_erk_43_cn	A Strang split using erk 43 for the hyperbolic subproblem and Crank-Nicolson for the parabolic subproblem
imex_11	A Euler IMEX splitting. This is the low order IMEX method: it performs a forward Euler time step for the hyperbolic subproblem and then a backward Euler time step for the parabolic subproblem.
imex_22	An implicit-explicit method that utilizes the Heun's second order explicit Runge-Kutta scheme with Butcher tableau \begin{align*} \begin{array}{c|ccc} 0 & 0 \\ 1 & 0.5 & 0 \\ 0.5 & 0 & 2 \\ \end{array} \end{align*} to solve the explicit subproblem and the two-stage Crank-Nicolson scheme diagonally implicit Runge-Kutta scheme with Butcher tableau \begin{align*} \begin{array}{c|ccc} 0 & 0 \\ 0.5 & 0 & \tfrac{1}{2} \\ 1 & 0 & 1 \\ \end{array} \end{align*} to solve the parabolic subproblem.
imex_33	An implicit-explicit method that utilizes the Heun's second order explicit Runge-Kutta scheme with Butcher tableau \begin{align*} \begin{array}{c|cccc} 0 & 0 \\ \tfrace{1}{3} & \tfrace{1}{3} & 0 \\ \tfrace{2}{3} & 0 & \tfrace{2}{3} & 0 \\ 1 & \tfrace{1}{4} & 0 & \tfrace{3}{4} \end{array} \end{align*} to solve the explicit subproblem and the two-stage Crank-Nicolson scheme diagonally implicit Runge-Kutta scheme with Butcher tableau \begin{align*} \begin{array}{c|cccc} 0 & 0 \\ \tfrace{1}{3} & \tfrace{1}{3} - \gamma & \gamma \\ \tfrace{2}{3} & \gamma & \tfrace{2}{3} - 2 \gamma & \gamma \\ 1 & \tfrace{1}{4} & 0 & \tfrace{3}{4} \end{array} \end{align*} with \gamma = \tfrace{1}{2} + \tfrace{1}{2\sqrt(3)} to solve the parabolic subproblem.

Definition at line 57 of file time_integrator.h.