wet_cylinder_water::ChainJoints Class Reference

#include <GaussPointDrag.h>

Public Member Functions
void	Begin (double length, bool closed=false)
void	Add (const Eigen::Vector3d &centre, const Eigen::Vector3d &axis)
void	Build ()
	Finds the joints and their positions from the elements added.
int	NumElements () const
	The number of elements in the chain.
int	NumJoints () const
	The number of joints: one more than the number of elements in an open chain, as many in a closed loop, none for an empty chain.
const Eigen::Vector3d &	JointPosition (int joint) const
	The position of joint joint [m], NED.
int	JointOfEnd (int element, int end) const
void	AppendJointPositions (std::vector< double > &points) const
void	QueryWater (const environment::wake::ElementFlowInteraction &flow, double T, int firstPoint)
EndWater	WaterOf (int element) const
	The water at the ends of element element, after QueryWater.

Detailed Description

The joints of a chain of equal elements, and the water at them.

Fill it with Begin, Add (once per element, in chain order) and Build; then QueryWater. The buffers keep their size from call to call, so a chain of fixed length allocates nothing after the first call.

In an open chain joint j lies between element j − 1 and element j; joint 0 is the free end of the first element, joint n the free end of the last. In a closed loop (at least three elements) there are n joints, and joint j lies between element j and element (j + 1) mod n. Which end of an element touches its neighbour is found from the geometry, not from the axis direction: the end of element i nearest the centre of element i + 1 goes to joint i + 1, the other end to joint i (the last element: the end nearest the centre of the one before goes to joint n − 1, the other to joint n).

Member Function Documentation

Add()

void wet_cylinder_water::ChainJoints::Add ( const Eigen::Vector3d &  centre, const Eigen::Vector3d &  axis  )

inline

Adds the next element of the chain.

Parameters

centre	The element's centre [m], NED.
axis	Its unit axis.

AppendJointPositions()

void wet_cylinder_water::ChainJoints::AppendJointPositions ( std::vector< double > &  points ) const

inline

Appends the joint positions to the points of a wake take (3 coordinates per joint, NED), in joint order.

Parameters

points

The points the wakes are taken at; joint j becomes point firstPoint + j, with firstPoint the number of points already in it.

Begin()

void wet_cylinder_water::ChainJoints::Begin ( double  length, bool  closed = false  )

inline

Starts a new chain and forgets the old one.

Parameters

length	The length of every element [m].
closed	True for a closed loop: the last element is a neighbour of the first.

JointOfEnd()

int wet_cylinder_water::ChainJoints::JointOfEnd ( int  element, int  end  ) const

inline

The joint at an end of an element.

Parameters

element	The element's index in the chain.
end	0 for the minus end, 1 for the plus end.

QueryWater()

void wet_cylinder_water::ChainJoints::QueryWater ( const environment::wake::ElementFlowInteraction &  flow, double  T, int  firstPoint  )

inline

Queries the water velocity once at every joint. The wakes are taken at the joints, so joint j takes point firstPoint + j.

Parameters

flow	The element flow.
T	Time [s].
firstPoint	The point of joint 0 (the points of the joints are consecutive).

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

• webfhsim/reloadrepos/fhsim_marine_elements/src/cable/GaussPointDrag.h