Description

Base class for a system for fluid-solid interaction problems.

This class is used to represent fluid-solid interaction problems consisting of fluid dynamics and multibody system. Each of the two underlying physics is an independent object owned and instantiated by this class. A derived class must always set the FSI interface for coupling the two physics systems.

#include <ChFsiSystem.h>

Inheritance diagram for chrono::fsi::ChFsiSystem:

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Collaboration diagram for chrono::fsi::ChFsiSystem:

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Classes
class	MBDCallback
	Class to specify step dynamics for the associated multibody system. More...

Public Member Functions
virtual	~ChFsiSystem ()
	Destructor for the FSI system.

void	AttachFluidSystem (ChFsiFluidSystem *sys)
	Attach a fluid system.

void	AttachMultibodySystem (ChSystem *sys)
	Attach a MBS system.

ChFsiFluidSystem &	GetFluidSystem () const
	Access the associated fluid system.

ChSystem &	GetMultibodySystem () const
	Access the associated multibody system.

ChFsiInterface &	GetFsiInterface () const
	Access the associated FSI interface.

void	SetVerbose (bool verbose)
	Enable/disable verbose terminal output (default: true). More...

void	SetGravitationalAcceleration (const ChVector3d &gravity)
	Set gravitational acceleration for the FSI system. More...

void	SetStepSizeCFD (double step)
	Set integration step size for fluid dynamics.

void	SetStepsizeMBD (double step)
	Set integration step size for multibody dynamics. More...

std::shared_ptr< FsiBody >	AddFsiBody (std::shared_ptr< ChBody > body, std::shared_ptr< ChBodyGeometry > geometry, bool check_embedded)
	Add a rigid body to the FSI system.

virtual void	Initialize ()
	Initialize the FSI system. More...

void	RegisterMBDCallback (std::shared_ptr< MBDCallback > callback)
	Set a custom function for advancing the dynamics of the associated multibody system. More...

void	DoStepDynamics (double step)
	Function to advance the FSI system combined state. More...

double	GetSimTime () const
	Get current simulation time.

double	GetStepSizeMBD () const
	Get the integration step size for multibody dynamics.

double	GetStepSizeCFD () const
	Get the integration step size for fluid dynamics.

double	GetRtf () const
	Get current estimated RTF (real time factor) for the coupled problem.

void	SetRtf (double rtf)
	Set RTF value for the coupled problem. More...

double	GetRtfCFD () const
	Get current estimated RTF (real time factor) for the fluid system.

double	GetRtfMBD () const
	Get current estimated RTF (real time factor) for the multibody system.

double	GetRatioMBD () const
	Get ratio of simulation time spent in MBS integration.

double	GetTimerStep () const
	Return the time in seconds for for simulating the last step.

double	GetTimerCFD () const
	Return the time in seconds for fluid dynamics over the last step.

double	GetTimerMBD () const
	Return the time in seconds for multibody dynamics over the last step.

double	GetTimerFSI () const
	Return the time in seconds for data exchange between phases over the last step.

const std::vector< std::shared_ptr< FsiBody > > &	GetBodies () const
	Get a list of the FSI rigid bodies.

const ChVector3d &	GetFsiBodyForce (size_t i) const
	Return the FSI applied force on the body with specified index (as returned by AddFsiBody). More...

const ChVector3d &	GetFsiBodyTorque (size_t i) const
	Return the FSI applied torque on the body with specified index (as returned by AddFsiBody). More...

Protected Member Functions
	ChFsiSystem (ChSystem sysMBS, ChFsiFluidSystem sysCFD)
	Construct an FSI system coupling the provided multibody and fluid systems. More...

Protected Attributes
ChSystem *	m_sysMBS
	multibody system

ChFsiFluidSystem *	m_sysCFD
	FSI fluid solver.

std::shared_ptr< ChFsiInterface >	m_fsi_interface
	FSI interface system.

bool	m_verbose
	enable/disable m_verbose terminal output

bool	m_is_initialized
	set to true once the Initialize function is called

Constructor & Destructor Documentation

◆ ChFsiSystem()

chrono::fsi::ChFsiSystem::ChFsiSystem	(	ChSystem *	sysMBS,
		ChFsiFluidSystem *	sysCFD
	)

protected

Construct an FSI system coupling the provided multibody and fluid systems.

Derived classes must also construct and set the FSI interface (m_fsi_interface).

Member Function Documentation

◆ DoStepDynamics()

void chrono::fsi::ChFsiSystem::DoStepDynamics ( double step )

Function to advance the FSI system combined state.

This implements an explicit force-displacement co-simulation step:

advance fluid dynamics (CFD) to new data exchange point;
advance multibody dynamics (MBD) to new data exchange point;
extract (from fluid system) and apply (to MBS) fluid forces on FSI solid objects;
extract (from MBS) and apply (to fluid system) new states for FSI solid objects; Notes:
no data exchange is performed before the first step; this assumes that FSI solid states and FSI solid forces are properly initialized
CFD advance calls ChFsiFluidSystem::DoStepDynamics multiple times (see SetStepsizeCFD);
MBD advance is executed in a separate, concurrent thread and does not block execution;
the caller can register a custom callback (of type ChFsiSystem::MBDCallback) to control MBD advance;
if MBDCallback not provided, MBD advance calls ChSystem::DoStepDynamics multiple times (see SetStepsizeMBD);

◆ GetFsiBodyForce()

const ChVector3d & chrono::fsi::ChFsiSystem::GetFsiBodyForce ( size_t i ) const

Return the FSI applied force on the body with specified index (as returned by AddFsiBody).

The force is applied at the body COM and is expressed in the absolute frame.

◆ GetFsiBodyTorque()

const ChVector3d & chrono::fsi::ChFsiSystem::GetFsiBodyTorque ( size_t i ) const

Return the FSI applied torque on the body with specified index (as returned by AddFsiBody).

The torque is expressed in the absolute frame.

◆ Initialize()

void chrono::fsi::ChFsiSystem::Initialize ( )

virtual

Initialize the FSI system.

A call to this function marks the completion of system construction. The default implementation performs the following operations:

check that an associated FSI interface was created and a value for integration step size was provided;
initialize the FSI interface;
get initial solid states from the FSI interface;
initialize the associated fluid solver, passing the initial solid states;

Reimplemented in chrono::fsi::sph::ChFsiSystemSPH, and chrono::fsi::tdpf::ChFsiSystemTDPF.

◆ RegisterMBDCallback()

void chrono::fsi::ChFsiSystem::RegisterMBDCallback ( std::shared_ptr< MBDCallback > callback )

inline

Set a custom function for advancing the dynamics of the associated multibody system.

If not provided, the MBS system is integrated with the specified step size (see SetStepsizeMBD) by calling ChSystem::DoStepDynamics.

◆ SetGravitationalAcceleration()

void chrono::fsi::ChFsiSystem::SetGravitationalAcceleration ( const ChVector3d & gravity )

Set gravitational acceleration for the FSI system.

This function sets gravity for both the fluid and multibody systems.

◆ SetRtf()

void chrono::fsi::ChFsiSystem::SetRtf ( double rtf )

inline

Set RTF value for the coupled problem.

This is necessary for correct reporting if automatic integration of the multibody system dynamics is disabled and performed externally.

◆ SetStepsizeMBD()

void chrono::fsi::ChFsiSystem::SetStepsizeMBD ( double step )

Set integration step size for multibody dynamics.

If a value is not provided, the MBS system is integrated with the same step used for fluid dynamics.

◆ SetVerbose()

void chrono::fsi::ChFsiSystem::SetVerbose ( bool verbose )

Enable/disable verbose terminal output (default: true).

The default implementation sets the verbose mode for the FSI system and the underlying FSI interface.

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

/builds/uwsbel/chrono/src/chrono_fsi/ChFsiSystem.h
/builds/uwsbel/chrono/src/chrono_fsi/ChFsiSystem.cpp