This implements a solver for a single parameter instability problem, for example a flutter solver where reduced frequency is the primary parameter. More...

#include <ug_flutter_solver.h>

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Public Member Functions
	UGFlutterSolver ()
	defalut constructor More...

virtual	~UGFlutterSolver ()

void	clear ()
	clears the solution and other data from this solver More...

virtual void	clear_solutions ()
	clears the solutions stored from a previous analysis. More...

void	initialize (MAST::Parameter &kr_param, MAST::Parameter &bref_param, Real rho, Real kr_lower, Real kr_upper, unsigned int n_kr_divs, std::vector< libMesh::NumericVector< Real > * > &basis)
	initializes the data structres for a flutter solution. More...

virtual unsigned int	n_roots_found () const
	finds the number of critical points already identified in the procedure. More...

const MAST::FlutterRootBase &	get_root (const unsigned int n) const
	returns the `n` th root in terms of ascending velocity that is found by the solver More...

virtual std::pair< bool, MAST::FlutterRootBase * >	find_next_root (const Real g_tol, const unsigned int n_bisection_iters)
	Looks through the list of flutter cross-over points and iteratively zooms in to find the cross-over point. More...

virtual std::pair< bool, MAST::FlutterRootBase * >	find_critical_root (const Real g_tol, const unsigned int n_bisection_iters)
	This method checks if the flutter root corresponding to the lowest velocity crossover has been calculated. More...

virtual void	calculate_sensitivity (MAST::FlutterRootBase &root, const MAST::FunctionBase &f, libMesh::NumericVector< Real > dXdp=nullptr, libMesh::NumericVector< Real > dXdkr=nullptr)
	Calculate the sensitivity of the flutter root with respect to the `f` parameter. More...

virtual void	print_sorted_roots ()
	Prints the sorted roots to the `output`. More...

virtual void	print_crossover_points ()
	Prints the crossover points output. More...

virtual void	scan_for_roots ()
	Scans for flutter roots in the analyzed points, and identified the divergence (if k_red = 0. More...

Public Member Functions inherited from MAST::FlutterSolverBase
	FlutterSolverBase ()
	defalut constructor More...

virtual	~FlutterSolverBase ()

void	attach_assembly (MAST::StructuralFluidInteractionAssembly &assembly)
	attaches the assembly object to this solver. More...

void	attach_steady_solver (MAST::FlutterSolverBase::SteadySolver &solver)
	attaches the steady solution object More...

virtual void	clear_assembly_object ()
	clears the assembly object More...

void	initialize (std::vector< libMesh::NumericVector< Real > * > &basis)
	initializes the data structres for a flutter solution. More...

void	set_output_file (const std::string &nm)

Protected Member Functions
virtual std::unique_ptr< MAST::FlutterSolutionBase >	_analyze (const Real kr_ref, const MAST::FlutterSolutionBase *prev_sol=nullptr)
	performs an eigensolution at the specified reference value, and sort the roots based on the provided solution pointer. More...

virtual std::pair< bool, MAST::FlutterSolutionBase * >	_bisection_search (const std::pair< MAST::FlutterSolutionBase , MAST::FlutterSolutionBase > &ref_sol_range, const unsigned int root_num, const Real g_tol, const unsigned int max_iters)
	bisection method search More...

void	_initialize_matrices (Real kr, ComplexMatrixX &A, ComplexMatrixX &B)
	Assembles the reduced order system structural and aerodynmaic matrices for specified reduced freq `kr`. More...

void	_initialize_matrix_sensitivity_for_param (const MAST::FunctionBase &f, const libMesh::NumericVector< Real > &dXdp, Real kr, ComplexMatrixX &A, ComplexMatrixX &B)
	Assembles the reduced order system structural and aerodynmaic matrices for specified flight velocity `U_inf`. More...

void	_initialize_matrix_sensitivity_for_kr (Real kr, ComplexMatrixX &A, ComplexMatrixX &B)
	Assembles the sensitivity of matrices wrt kr. More...

virtual void	_identify_crossover_points ()
	identifies all cross-over and divergence points from analyzed roots More...

Protected Attributes
MAST::Parameter *	_kr_param
	Parameter that define the reduced frequency. More...

MAST::Parameter *	_bref_param
	reference chord More...

Real	_rho
	flight density More...

std::pair< Real, Real >	_kr_range
	range of reference values within which to find flutter roots More...

unsigned int	_n_kr_divs
	number of division in the reference value range for initial scanning More...

std::map< Real, MAST::FlutterSolutionBase * >	_flutter_solutions
	map of kr sorted flutter solutions More...

bool	_include_highest_kr_unstable
	flag allows check to see if the root started out as critical at the highest k value. More...

std::multimap< Real, MAST::FlutterRootCrossoverBase * >	_flutter_crossovers
	the map of flutter crossover points versus average kr of the two bounding roots More...

Protected Attributes inherited from MAST::FlutterSolverBase
MAST::StructuralFluidInteractionAssembly *	_assembly
	structural assembly that provides the assembly of the system matrices. More...

std::vector< libMesh::NumericVector< Real > * > *	_basis_vectors
	basis vector used to define the reduced order model More...

std::ofstream *	_output
	file to which the result will be written More...

MAST::FlutterSolverBase::SteadySolver *	_steady_solver
	object provides the steady state solution. More...

Detailed Description

This implements a solver for a single parameter instability problem, for example a flutter solver where reduced frequency is the primary parameter.

Definition at line 41 of file ug_flutter_solver.h.

Constructor & Destructor Documentation

MAST::UGFlutterSolver::UGFlutterSolver ( )

defalut constructor

Definition at line 35 of file ug_flutter_solver.cpp.

MAST::UGFlutterSolver::~UGFlutterSolver ( )

virtual

Definition at line 47 of file ug_flutter_solver.cpp.

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Member Function Documentation

std::unique_ptr< MAST::FlutterSolutionBase > MAST::UGFlutterSolver::_analyze	(	const Real	kr_ref,
		const MAST::FlutterSolutionBase *	prev_sol = `nullptr`
	)

protectedvirtual

performs an eigensolution at the specified reference value, and sort the roots based on the provided solution pointer.

If the pointer is nullptr, then no sorting is performed

Definition at line 486 of file ug_flutter_solver.cpp.

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std::pair< bool, MAST::FlutterSolutionBase * > MAST::UGFlutterSolver::_bisection_search	(	const std::pair< MAST::FlutterSolutionBase , MAST::FlutterSolutionBase > &	ref_sol_range,
		const unsigned int	root_num,
		const Real	g_tol,
		const unsigned int	max_iters
	)

protectedvirtual

bisection method search

Definition at line 407 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::_identify_crossover_points ( )

protectedvirtual

identifies all cross-over and divergence points from analyzed roots

Definition at line 692 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::_initialize_matrices	(	Real	kr,
		ComplexMatrixX &	A,
		ComplexMatrixX &	B
	)

protected

Assembles the reduced order system structural and aerodynmaic matrices for specified reduced freq kr.

Definition at line 522 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::_initialize_matrix_sensitivity_for_kr	(	Real	kr,
		ComplexMatrixX &	A,
		ComplexMatrixX &	B
	)

protected

Assembles the sensitivity of matrices wrt kr.

Definition at line 640 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::_initialize_matrix_sensitivity_for_param	(	const MAST::FunctionBase &	f,
		const libMesh::NumericVector< Real > &	dXdp,
		Real	kr,
		ComplexMatrixX &	A,
		ComplexMatrixX &	B
	)

protected

Assembles the reduced order system structural and aerodynmaic matrices for specified flight velocity U_inf.

Definition at line 578 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::calculate_sensitivity	(	MAST::FlutterRootBase &	root,
		const MAST::FunctionBase &	f,
		libMesh::NumericVector< Real > *	dXdp = `nullptr`,
		libMesh::NumericVector< Real > *	dXdkr = `nullptr`
	)

virtual

Calculate the sensitivity of the flutter root with respect to the f parameter.

If the base solution has a sensitivity with respect to the parameter, then that should be provided through dXdp. The sensitivity solution also requires sensitivity of the eigenvalue wrt velocity, which is defined as a parameter. Hence, the sensitivity of the static solution is also required wrt the velocity parameter. If dXdV is nullptr, then zero value is assumed.

Definition at line 871 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::clear ( )

virtual

clears the solution and other data from this solver

Reimplemented from MAST::FlutterSolverBase.

Definition at line 56 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::clear_solutions ( )

virtual

clears the solutions stored from a previous analysis.

Definition at line 96 of file ug_flutter_solver.cpp.

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std::pair< bool, MAST::FlutterRootBase * > MAST::UGFlutterSolver::find_critical_root	(	const Real	g_tol,
		const unsigned int	n_bisection_iters
	)

virtual

This method checks if the flutter root corresponding to the lowest velocity crossover has been calculated.

If not, then it attempts to find that root using an iterative approach

Definition at line 208 of file ug_flutter_solver.cpp.

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std::pair< bool, MAST::FlutterRootBase * > MAST::UGFlutterSolver::find_next_root	(	const Real	g_tol,
		const unsigned int	n_bisection_iters
	)

virtual

Looks through the list of flutter cross-over points and iteratively zooms in to find the cross-over point.

This should be called only after scan_for_roots() has been called. Potential cross-over points are sorted with increasing velocity, and this method will attempt to identify the next critical root in the order.

Definition at line 163 of file ug_flutter_solver.cpp.

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const MAST::FlutterRootBase & MAST::UGFlutterSolver::get_root ( const unsigned int n ) const

returns the n th root in terms of ascending velocity that is found by the solver

Definition at line 137 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::initialize	(	MAST::Parameter &	kr_param,
		MAST::Parameter &	bref_param,
		Real	rho,
		Real	kr_lower,
		Real	kr_upper,
		unsigned int	n_kr_divs,
		std::vector< libMesh::NumericVector< Real > * > &	basis
	)

initializes the data structres for a flutter solution.

Definition at line 73 of file ug_flutter_solver.cpp.

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unsigned int MAST::UGFlutterSolver::n_roots_found ( ) const

virtual

finds the number of critical points already identified in the procedure.

Definition at line 118 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::print_crossover_points ( )

virtual

Prints the crossover points output.

If no pointer to output is given then the output defined by set_output_file() is used.

Implements MAST::FlutterSolverBase.

Definition at line 379 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::print_sorted_roots ( )

virtual

Prints the sorted roots to the output.

Implements MAST::FlutterSolverBase.

Definition at line 307 of file ug_flutter_solver.cpp.

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void MAST::UGFlutterSolver::scan_for_roots ( )

virtual

Scans for flutter roots in the analyzed points, and identified the divergence (if k_red = 0.

is specified) and flutter crossover points. The roots are organized in terms of increasing velocity.

Definition at line 262 of file ug_flutter_solver.cpp.

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Member Data Documentation

MAST::Parameter* MAST::UGFlutterSolver::_bref_param

protected

reference chord

Definition at line 227 of file ug_flutter_solver.h.

std::multimap<Real, MAST::FlutterRootCrossoverBase*> MAST::UGFlutterSolver::_flutter_crossovers

protected

the map of flutter crossover points versus average kr of the two bounding roots

Definition at line 265 of file ug_flutter_solver.h.

std::map<Real, MAST::FlutterSolutionBase*> MAST::UGFlutterSolver::_flutter_solutions

protected

map of kr sorted flutter solutions

Definition at line 252 of file ug_flutter_solver.h.

bool MAST::UGFlutterSolver::_include_highest_kr_unstable

protected

flag allows check to see if the root started out as critical at the highest k value.

Definition at line 259 of file ug_flutter_solver.h.

MAST::Parameter* MAST::UGFlutterSolver::_kr_param

protected

Parameter that define the reduced frequency.

Definition at line 221 of file ug_flutter_solver.h.

std::pair<Real, Real> MAST::UGFlutterSolver::_kr_range

protected

range of reference values within which to find flutter roots

Definition at line 239 of file ug_flutter_solver.h.

unsigned int MAST::UGFlutterSolver::_n_kr_divs

protected

number of division in the reference value range for initial scanning

Definition at line 246 of file ug_flutter_solver.h.

Real MAST::UGFlutterSolver::_rho

protected

flight density

Definition at line 233 of file ug_flutter_solver.h.

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

/home/travis/build/MASTmultiphysics/mast-multiphysics/src/aeroelasticity/ug_flutter_solver.h
/home/travis/build/MASTmultiphysics/mast-multiphysics/src/aeroelasticity/ug_flutter_solver.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation