This implements a solver for a single parameter instability problem, for example a flutter solver where flight speed is the primary parameter.
Definition at line 44 of file time_domain_flutter_solver.h.
#include <time_domain_flutter_solver.h>
Public Member Functions  
TimeDomainFlutterSolver ()  
defalut constructor More...  
virtual  ~TimeDomainFlutterSolver () 
virtual std::pair< bool, MAST::FlutterRootBase * >  analyze_and_find_critical_root_without_tracking (const Real g_tol, const unsigned int n_iters) 
This root starts with the lower velocity and increments the speed till a single unstable root is identified. More...  
virtual void  calculate_sensitivity (MAST::FlutterRootBase &root, const MAST::FunctionBase &f, libMesh::NumericVector< Real > *dXdp=nullptr, libMesh::NumericVector< Real > *dXdV=nullptr) 
Calculate the sensitivity of the flutter root with respect to the f parameter. More...  
virtual 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...  
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 std::pair< bool, MAST::FlutterRootBase * >  find_next_root (const Real g_tol, const unsigned int n_bisection_iters) 
Looks through the list of flutter crossover points and iteratively zooms in to find the crossover point. 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...  
void  initialize (MAST::Parameter &velocity_param, Real V_lower, Real V_upper, unsigned int n_V_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...  
virtual void  print_crossover_points () 
Prints the crossover points output. More...  
virtual void  print_sorted_roots () 
Prints the sorted roots to the 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::TimeDomainFlutterSolution >  _analyze (const Real v_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...  
virtual void  _identify_crossover_points () 
identifies all crossover and divergence points from analyzed roots More...  
void  _initialize_matrices (Real U_inf, RealMatrixX &A, RealMatrixX &B) 
Assembles the reduced order system structural and aerodynmaic matrices for specified flight velocity U_inf . More...  
void  _initialize_matrix_sensitivity_for_param (const MAST::FunctionBase &f, const libMesh::NumericVector< Real > &dXdp, Real U_inf, RealMatrixX &A, RealMatrixX &B) 
Assembles the reduced order system structural and aerodynmaic matrices for specified flight velocity U_inf . More...  
Protected Attributes  
std::multimap< Real, MAST::FlutterRootCrossoverBase * >  _flutter_crossovers 
the map of flutter crossover points versus average velocity of the two bounding roots More...  
std::map< Real, MAST::FlutterSolutionBase * >  _flutter_solutions 
map of velocity sorted flutter solutions More...  
unsigned int  _n_V_divs 
number of division in the reference value range for initial scanning More...  
std::pair< Real, Real >  _V_range 
range of reference values within which to find flutter roots More...  
MAST::Parameter *  _velocity_param 
Parameter that define the velocity. 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...  
MAST::TimeDomainFlutterSolver::TimeDomainFlutterSolver  (  ) 
defalut constructor
Definition at line 34 of file time_domain_flutter_solver.cpp.

virtual 
Definition at line 44 of file time_domain_flutter_solver.cpp.

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 640 of file time_domain_flutter_solver.cpp.

protectedvirtual 
bisection method search
Definition at line 568 of file time_domain_flutter_solver.cpp.

protectedvirtual 
identifies all crossover and divergence points from analyzed roots
Definition at line 822 of file time_domain_flutter_solver.cpp.

protected 
Assembles the reduced order system structural and aerodynmaic matrices for specified flight velocity U_inf
.
Definition at line 676 of file time_domain_flutter_solver.cpp.

protected 
Assembles the reduced order system structural and aerodynmaic matrices for specified flight velocity U_inf
.
Definition at line 754 of file time_domain_flutter_solver.cpp.

virtual 
This root starts with the lower velocity and increments the speed till a single unstable root is identified.
Definition at line 256 of file time_domain_flutter_solver.cpp.

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 992 of file time_domain_flutter_solver.cpp.

virtual 
clears the solution and other data from this solver
Reimplemented from MAST::FlutterSolverBase.
Definition at line 52 of file time_domain_flutter_solver.cpp.

virtual 
clears the solutions stored from a previous analysis.
Definition at line 86 of file time_domain_flutter_solver.cpp.

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 199 of file time_domain_flutter_solver.cpp.

virtual 
Looks through the list of flutter crossover points and iteratively zooms in to find the crossover point.
This should be called only after scan_for_roots() has been called. Potential crossover points are sorted with increasing velocity, and this method will attempt to identify the next critical root in the order.
Definition at line 153 of file time_domain_flutter_solver.cpp.
const MAST::FlutterRootBase & MAST::TimeDomainFlutterSolver::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 127 of file time_domain_flutter_solver.cpp.
void MAST::TimeDomainFlutterSolver::initialize  (  MAST::Parameter &  velocity_param, 
Real  V_lower,  
Real  V_upper,  
unsigned int  n_V_divs,  
std::vector< libMesh::NumericVector< Real > *> &  basis  
) 
initializes the data structres for a flutter solution.
Definition at line 68 of file time_domain_flutter_solver.cpp.

virtual 
finds the number of critical points already identified in the procedure.
Definition at line 108 of file time_domain_flutter_solver.cpp.

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 540 of file time_domain_flutter_solver.cpp.

virtual 
Prints the sorted roots to the output
.
Implements MAST::FlutterSolverBase.
Definition at line 468 of file time_domain_flutter_solver.cpp.

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 425 of file time_domain_flutter_solver.cpp.

protected 
the map of flutter crossover points versus average velocity of the two bounding roots
Definition at line 250 of file time_domain_flutter_solver.h.

protected 
map of velocity sorted flutter solutions
Definition at line 244 of file time_domain_flutter_solver.h.

protected 
number of division in the reference value range for initial scanning
Definition at line 238 of file time_domain_flutter_solver.h.
range of reference values within which to find flutter roots
Definition at line 231 of file time_domain_flutter_solver.h.

protected 
Parameter that define the velocity.
Definition at line 225 of file time_domain_flutter_solver.h.