serif::equations::MassNormalization Class Reference

Mass normalization equation, which enforces a global constraint on the total mass of a system. More...

#include <mass_normalization.hpp>

Inheritance diagram for serif::equations::MassNormalization:

Collaboration diagram for serif::equations::MassNormalization:

Public Types
using	Density = discretization::blocks::density::mass
	Alias for mass density.
using	ResidualQuantity = dimensions::Mass
	Alias for the dimension of the residual.
using	DensityValue = discretization::forms::Operand<Density>
	Alias for the operand type of the mass density.
using	Operands = utils::types::TypeList<DensityValue>
	The list of operands for the mass normalization equation.
Public Types inherited from serif::equations::Contribution< discretization::forms::Operand< discretization::blocks::barotropic_constant::mass_normalization > >
using	Test
	The test type of the contribution.
using	TestOperand
	The operand type of the contribution (associating a test function and a term)
using	Support
	The domain support of the contribution (which then boils down to the dofs which are supported by the term on that test function)

Public Member Functions
	MassNormalization (const double target_mass)
	Construct a mass normalization equation.
double	residual_offset () const
	Return the residual offset for the mass normalization equation.

Static Public Member Functions
static PointLinearization< Operands >	evaluate (const EquationPoint< Operands > &point)
	Evaluate the mass normalization equation point-wise integrand and its partial derivatives.
static int	additional_order (DensityValue, int)
	Return the additional quadrature order required for the operands of this equation.

Static Public Attributes
static constexpr std::string_view	name = "mass normalization"
	Compile time name for the mass normalization equation, used for debugging and logging.

Private Attributes
double	m_target_mass
	The target mass for the system, which must be finite and positive.

Detailed Description

Mass normalization equation, which enforces a global constraint on the total mass of a system.

Note

In the barotropic case the bernoulli constant as the control variable here. This is a "clever" choice in this case; however, more broadly most of this equation is general (its only that in we choose to inject the residual into the mass_normalization member of the barotropic_constant block). That could very easily become a more general control variable without changing the rest of this

Mass normalization, being an integral constraint must make use of the residual_offset() method to properly find the residual. See AngularMomentumConstraint for a more detailed discussion of this. Suffice it to say that these are point-wise integrands so if we were to subtract the target mass from every point we would wildly over count the target mass. Rather, we simply return the density everywhere as the volume integrated density will be the mass. Then the residual_offset() method returns the negative of the target mass (the backend automatically adds anything from this function, if it exists, to the integrated residual to get the final residual).

@contribution Residuals to the mass_normalization term in the barotropic_constant block. This is effectively a global constraint on the total mass of the system.

Member Typedef Documentation

Density

using serif::equations::MassNormalization::Density = discretization::blocks::density::mass

Alias for mass density.

DensityValue

using serif::equations::MassNormalization::DensityValue = discretization::forms::Operand<Density>

Alias for the operand type of the mass density.

Operands

using serif::equations::MassNormalization::Operands = utils::types::TypeList<DensityValue>

The list of operands for the mass normalization equation.

ResidualQuantity

using serif::equations::MassNormalization::ResidualQuantity = dimensions::Mass

Alias for the dimension of the residual.

Constructor & Destructor Documentation

MassNormalization()

serif::equations::MassNormalization::MassNormalization ( const double target_mass )

inlineexplicit

Construct a mass normalization equation.

Parameters

target_mass

The target mass for the system, which must be finite and positive.

Exceptions

std::invalid_argument

If the target mass is not finite or not positive.

Member Function Documentation

additional_order()

static int serif::equations::MassNormalization::additional_order ( DensityValue , int  )

inlinestaticnodiscard

Return the additional quadrature order required for the operands of this equation.

Parameters

operand	The operand type for which to determine the additional quadrature order. Note that this is only used to select the correct overload of this function. This particular version only has one overload; therefore this is really just their to maintain symmetry with other equation implementations.
position_order	The order of the position basis functions.

Returns

The additional quadrature order required for the given operand type (always 0 in this case).

evaluate()

static PointLinearization< Operands > serif::equations::MassNormalization::evaluate ( const EquationPoint< Operands > & point )

inlinestaticnodiscard

Evaluate the mass normalization equation point-wise integrand and its partial derivatives.

The point-wise integrand is calculated as \( \rho \), where \( \rho \) is the model density. The partial derivative is calculated as:

• \( \frac{\partial r}{\partial \rho} = 1 \)

Note

As the class description notes, the residual is not calculated as \( \rho - M_{\text{target}} \) because this would over count the target mass. Instead we simply return the density and then use the residual_offset() method to subtract the target mass from the integrated residual.

Parameters

point

The point at which to evaluate the equation.

Returns

The point-wise linearization of the mass normalization equation, which contains the residual and the partial derivative with respect to the model density.

residual_offset()

double serif::equations::MassNormalization::residual_offset ( ) const

inlinenodiscard

Return the residual offset for the mass normalization equation.

The backend integrates the point-wise residual integrand over the domain. The global constraint is satisfied when the total mass equals the target value. Therefore we subtract the target from the integrated residual to get the actual residual.

Note

The backend automatically looks for this method and calls it if it exists.

The backend actually adds whatever is returned from this function to the integrated residual to get the final residual. Therefore we return the negative of the target mass here.

Returns

The negative of the target mass, \(-M_{\text{target}}\).

Member Data Documentation

m_target_mass

double serif::equations::MassNormalization::m_target_mass

private

The target mass for the system, which must be finite and positive.

name

std::string_view serif::equations::MassNormalization::name = "mass normalization"

staticconstexpr

Compile time name for the mass normalization equation, used for debugging and logging.

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

• src/include/serif/equations/mass_normalization.hpp