#include <source/euler_aeos/riemann_solver.h>

Public Types
using	View = HyperbolicSystemView< dim, Number >

using	primitive_type = std::array< Number, riemann_data_size >

using	state_type = typename View::state_type

using	precomputed_state_type = typename View::precomputed_state_type

using	ScalarNumber = typename View::ScalarNumber

using	Parameters = RiemannSolverParameters< ScalarNumber >

Public Member Functions
Compute wavespeed estimates
	RiemannSolver (const HyperbolicSystem &hyperbolic_system, const Parameters &parameters, const MultiComponentVector< ScalarNumber, n_precomputed_values > &precomputed_values)

Number	compute (const primitive_type &riemann_data_i, const primitive_type &riemann_data_j) const

Number	compute (const state_type &U_i, const state_type &U_j, const unsigned int i, const unsigned int *js, const dealii::Tensor< 1, dim, Number > &n_ij) const

Static Public Attributes
static constexpr unsigned int	problem_dimension = View::problem_dimension

static constexpr unsigned int	riemann_data_size = 5

static constexpr unsigned int	n_precomputed_values

Internal functions used in the Riemann solver
Number	c (const Number gamma_Z) const

Number	alpha (const Number &rho, const Number &gamma, const Number &a) const

Number	p_star_RS_full (const primitive_type &riemann_data_i, const primitive_type &riemann_data_j) const

Number	p_star_SS_full (const primitive_type &riemann_data_i, const primitive_type &riemann_data_j) const

Number	p_star_failsafe (const primitive_type &riemann_data_i, const primitive_type &riemann_data_j) const

Number	p_star_interpolated (const primitive_type &riemann_data_i, const primitive_type &riemann_data_j) const

Number	phi_of_p_max (const primitive_type &riemann_data_i, const primitive_type &riemann_data_j) const

Number	lambda1_minus (const primitive_type &riemann_data, const Number p_star) const

Number	lambda3_plus (const primitive_type &primitive_state, const Number p_star) const

Number	compute_lambda (const primitive_type &riemann_data_i, const primitive_type &riemann_data_j, const Number p_star) const

primitive_type	riemann_data_from_state (const state_type &U, const Number &p, const dealii::Tensor< 1, dim, Number > &n_ij) const

Detailed Description

template<int dim, typename Number = double>
class ryujin::EulerAEOS::RiemannSolver< dim, Number >

A fast approximative solver for the 1D Riemann problem. The solver ensures that the estimate \(\lambda_{\text{max}}\) that is returned for the maximal wavespeed is a strict upper bound.

The solver is based on [2].

Definition at line 40 of file riemann_solver.h.

Member Typedef Documentation

◆ View

template<int dim, typename Number = double>

using ryujin::EulerAEOS::RiemannSolver< dim, Number >::View = HyperbolicSystemView<dim, Number>

A view of the HyperbolicSystem that makes methods available for a given dimension dim and choice of number type Number (which can be a scalar float, or double, as well as a VectorizedArray holding packed scalars.

Intended usage:

HyperbolicSystem hyperbolic_system;
const auto view = hyperbolic_system.template view<dim, Number>();
const auto flux_i = view.flux_contribution(...);
const auto flux_j = view.flux_contribution(...);
const auto flux_ij = view.flux_divergence(flux_i, flux_j, c_ij);
// etc.

Definition at line 46 of file riemann_solver.h.

◆ primitive_type

template<int dim, typename Number = double>

using ryujin::EulerAEOS::RiemannSolver< dim, Number >::primitive_type = std::array<Number, riemann_data_size>

The array type to store the expanded primitive state for the Riemann solver \([\rho, v, p, a]\)

Definition at line 63 of file riemann_solver.h.

◆ state_type

template<int dim, typename Number = double>

using ryujin::EulerAEOS::RiemannSolver< dim, Number >::state_type = typename View::state_type

The storage type used for a (conserved) state \(\boldsymbol U\).

Definition at line 68 of file riemann_solver.h.

◆ precomputed_state_type

template<int dim, typename Number = double>

using ryujin::EulerAEOS::RiemannSolver< dim, Number >::precomputed_state_type = typename View::precomputed_state_type

Array type used for precomputed values.

Definition at line 79 of file riemann_solver.h.

◆ ScalarNumber

template<int dim, typename Number = double>

using ryujin::EulerAEOS::RiemannSolver< dim, Number >::ScalarNumber = typename View::ScalarNumber

The underlying scalar number type.

Definition at line 84 of file riemann_solver.h.

◆ Parameters

template<int dim, typename Number = double>

using ryujin::EulerAEOS::RiemannSolver< dim, Number >::Parameters = RiemannSolverParameters<ScalarNumber>

Definition at line 89 of file riemann_solver.h.

Constructor & Destructor Documentation

◆ RiemannSolver()

template<int dim, typename Number = double>

ryujin::EulerAEOS::RiemannSolver< dim, Number >::RiemannSolver	(	const HyperbolicSystem &	hyperbolic_system,
		const Parameters &	parameters,
		const MultiComponentVector< ScalarNumber, n_precomputed_values > &	precomputed_values
	)

inline

Constructor taking a HyperbolicSystem instance as argument

Definition at line 99 of file riemann_solver.h.

Member Function Documentation

◆ compute() [1/2]

template<int dim, typename Number >

Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::compute	(	const primitive_type &	riemann_data_i,
		const primitive_type &	riemann_data_j
	)		const

For two given 1D primitive states riemann_data_i and riemann_data_j, compute an estimate for an upper bound of the maximum wavespeed lambda.

Definition at line 536 of file riemann_solver.template.h.

◆ compute() [2/2]

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::compute	(	const state_type &	U_i,
		const state_type &	U_j,
		const unsigned int	i,
		const unsigned int *	js,
		const dealii::Tensor< 1, dim, Number > &	n_ij
	)		const

inline

For two given states U_i a U_j and a (normalized) "direction" n_ij compute an estimate for an upper bound of the maximum wavespeed lambda.

Definition at line 621 of file riemann_solver.template.h.

◆ c()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::c ( const Number gamma_Z ) const

inlineprotected

FIXME

Cost: 0x pow, 1x division, 1x sqrt

Definition at line 52 of file riemann_solver.template.h.

◆ alpha()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::alpha	(	const Number &	rho,
		const Number &	gamma,
		const Number &	a
	)		const

inlineprotected

FIXME

Cost: 0x pow, 1x division, 0x sqrt

Definition at line 85 of file riemann_solver.template.h.

◆ p_star_RS_full()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::p_star_RS_full	(	const primitive_type &	riemann_data_i,
		const primitive_type &	riemann_data_j
	)		const

inlineprotected

Compute the best available, but expensive, upper bound on the expansion-shock case as described in §5.4, Eqn. (5.7) and (5.8) in [2]

Cost: 5x pow, 11x division, 1x sqrt

Definition at line 102 of file riemann_solver.template.h.

References ryujin::positive_part(), and ryujin::pow().

◆ p_star_SS_full()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::p_star_SS_full	(	const primitive_type &	riemann_data_i,
		const primitive_type &	riemann_data_j
	)		const

inlineprotected

Compute the best available, but expensive, upper bound on the shock-shock case as described in §5.5, Eqn. (5.10) and (5.12) in [2]

Cost: 2x pow, 9x division, 3x sqrt

Definition at line 198 of file riemann_solver.template.h.

References ryujin::positive_part(), and ryujin::pow().

◆ p_star_failsafe()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::p_star_failsafe	(	const primitive_type &	riemann_data_i,
		const primitive_type &	riemann_data_j
	)		const

inlineprotected

Definition at line 241 of file riemann_solver.template.h.

◆ p_star_interpolated()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::p_star_interpolated	(	const primitive_type &	riemann_data_i,
		const primitive_type &	riemann_data_j
	)		const

inlineprotected

Definition at line 290 of file riemann_solver.template.h.

References ryujin::positive_part(), and ryujin::pow().

◆ phi_of_p_max()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::phi_of_p_max	(	const primitive_type &	riemann_data_i,
		const primitive_type &	riemann_data_j
	)		const

inlineprotected

See [2]

The approximate Riemann solver is based on a function phi(p) that is montone increasing in p, concave down and whose (weak) third derivative is non-negative and locally bounded. Because we actually do not perform any iteration for computing our wavespeed estimate we can get away by only implementing a specialized variant of the phi function that computes phi(p_max). It inlines the implementation of the "f" function and eliminates all unnecessary branches in "f".

Cost: 0x pow, 2x division, 2x sqrt

Definition at line 419 of file riemann_solver.template.h.

◆ lambda1_minus()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::lambda1_minus	(	const primitive_type &	riemann_data,
		const Number	p_star
	)		const

inlineprotected

See [6] page 912, (3.7)

Cost: 0x pow, 1x division, 1x sqrt

Definition at line 449 of file riemann_solver.template.h.

References ryujin::positive_part().

◆ lambda3_plus()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::lambda3_plus	(	const primitive_type &	primitive_state,
		const Number	p_star
	)		const

inlineprotected

See [6] page 912, (3.8)

Cost: 0x pow, 1x division, 1x sqrt

Definition at line 465 of file riemann_solver.template.h.

References ryujin::positive_part().

◆ compute_lambda()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE Number ryujin::EulerAEOS::RiemannSolver< dim, Number >::compute_lambda	(	const primitive_type &	riemann_data_i,
		const primitive_type &	riemann_data_j,
		const Number	p_star
	)		const

inlineprotected

See [6] page 912, (3.9)

For two given primitive states riemann_data_i and riemann_data_j, and a guess p_2, compute an upper bound for lambda.

Cost: 0x pow, 2x division, 2x sqrt (inclusive)

Definition at line 481 of file riemann_solver.template.h.

References ryujin::negative_part(), and ryujin::positive_part().

◆ riemann_data_from_state()

template<int dim, typename Number >

DEAL_II_ALWAYS_INLINE auto ryujin::EulerAEOS::RiemannSolver< dim, Number >::riemann_data_from_state	(	const state_type &	U,
		const Number &	p,
		const dealii::Tensor< 1, dim, Number > &	n_ij
	)		const

inlineprotected

For a given (2+dim dimensional) state vector U, and a (normalized) "direction" n_ij, first compute the corresponding projected state in the corresponding 1D Riemann problem, and then compute and return the Riemann data [rho, u, p, a] (used in the approximative Riemann solver).

Definition at line 495 of file riemann_solver.template.h.

References AssertThrowSIMD.

Member Data Documentation

◆ problem_dimension

template<int dim, typename Number = double>

constexpr unsigned int ryujin::EulerAEOS::RiemannSolver< dim, Number >::problem_dimension = View::problem_dimension

staticconstexpr

The dimension of the state space.

Definition at line 51 of file riemann_solver.h.

◆ riemann_data_size

template<int dim, typename Number = double>

constexpr unsigned int ryujin::EulerAEOS::RiemannSolver< dim, Number >::riemann_data_size = 5

staticconstexpr

Number of components in a primitive state, we store \([\rho, v, p, a, gamma]\), thus, 5.

Definition at line 57 of file riemann_solver.h.

◆ n_precomputed_values

template<int dim, typename Number = double>

constexpr unsigned int ryujin::EulerAEOS::RiemannSolver< dim, Number >::n_precomputed_values

staticconstexpr

Initial value:

=

View::n_precomputed_values

ryujin::EulerAEOS::HyperbolicSystemView::n_precomputed_values

static constexpr unsigned int n_precomputed_values

Definition: hyperbolic_system.h:383

The number of precomputed values.

Definition at line 73 of file riemann_solver.h.

The documentation for this class was generated from the following files:

source/euler_aeos/riemann_solver.h
source/euler_aeos/riemann_solver.template.h

Public Types

Public Member Functions

Static Public Attributes

Internal functions used in the Riemann solver

Detailed Description

Member Typedef Documentation

◆ View

◆ primitive_type

◆ state_type

◆ precomputed_state_type

◆ ScalarNumber

◆ Parameters

Constructor & Destructor Documentation

◆ RiemannSolver()

Member Function Documentation

◆ compute() [1/2]

◆ compute() [2/2]

◆ c()

◆ alpha()

◆ p_star_RS_full()

◆ p_star_SS_full()

◆ p_star_failsafe()

◆ p_star_interpolated()

◆ phi_of_p_max()

◆ lambda1_minus()

◆ lambda3_plus()

◆ compute_lambda()

◆ riemann_data_from_state()

Member Data Documentation

◆ problem_dimension

◆ riemann_data_size

◆ n_precomputed_values