XSec and Airfoil Functions

This group of functions provides API control of cross-sections (XSecs). Airfoils are a type of XSec included in this group as well. API functions for Body of Revolution XSecs are included in the Specialized Geometry group. Click here to return to the main page. More...

Functions
void	vsp::CutXSec (const std::string &geom_id, int index)
void	vsp::CopyXSec (const std::string &geom_id, int index)
void	vsp::PasteXSec (const std::string &geom_id, int index)
void	vsp::InsertXSec (const std::string &geom_id, int index, int type)
int	vsp::GetXSecShape (const std::string &xsec_id)
double	vsp::GetXSecWidth (const std::string &xsec_id)
double	vsp::GetXSecHeight (const std::string &xsec_id)
void	vsp::SetXSecWidthHeight (const std::string &xsec_id, double w, double h)
void	vsp::SetXSecWidth (const std::string &xsec_id, double w)
void	vsp::SetXSecHeight (const std::string &xsec_id, double h)
std::vector< std::string >	vsp::GetXSecParmIDs (const std::string &xsec_id)
std::string	vsp::GetXSecParm (const std::string &xsec_id, const std::string &name)
std::vector< vec3d >	vsp::ReadFileXSec (const std::string &xsec_id, const std::string &file_name)
void	vsp::SetXSecPnts (const std::string &xsec_id, std::vector< vec3d > &pnt_vec)
vec3d	vsp::ComputeXSecPnt (const std::string &xsec_id, double fract)
vec3d	vsp::ComputeXSecTan (const std::string &xsec_id, double fract)
void	vsp::ResetXSecSkinParms (const std::string &xsec_id)
void	vsp::SetXSecContinuity (const std::string &xsec_id, int cx)
void	vsp::SetXSecTanAngles (const std::string &xsec_id, int side, double top, double right, double bottom, double left)
void	vsp::SetXSecTanSlews (const std::string &xsec_id, int side, double top, double right, double bottom, double left)
void	vsp::SetXSecTanStrengths (const std::string &xsec_id, int side, double top, double right, double bottom, double left)
void	vsp::SetXSecCurvatures (const std::string &xsec_id, int side, double top, double right, double bottom, double left)
void	vsp::ReadFileAirfoil (const std::string &xsec_id, const std::string &file_name)
void	vsp::SetAirfoilUpperPnts (const std::string &xsec_id, const std::vector< vec3d > &up_pnt_vec)
void	vsp::SetAirfoilLowerPnts (const std::string &xsec_id, const std::vector< vec3d > &low_pnt_vec)
void	vsp::SetAirfoilPnts (const std::string &xsec_id, const std::vector< vec3d > &up_pnt_vec, const std::vector< vec3d > &low_pnt_vec)
std::vector< vec3d >	vsp::GetHersheyBarLiftDist (const int &npts, const double &alpha, const double &Vinf, const double &span, bool full_span_flag=false)
std::vector< vec3d >	vsp::GetHersheyBarDragDist (const int &npts, const double &alpha, const double &Vinf, const double &span, bool full_span_flag=false)
std::vector< vec3d >	vsp::GetVKTAirfoilPnts (const int &npts, const double &alpha, const double &epsilon, const double &kappa, const double &tau)
std::vector< double >	vsp::GetVKTAirfoilCpDist (const double &alpha, const double &epsilon, const double &kappa, const double &tau, std::vector< vec3d > xyz_data)
std::vector< vec3d >	vsp::GetEllipsoidSurfPnts (const vec3d &center, const vec3d &abc_rad, int u_npts=20, int w_npts=20)
std::vector< vec3d >	vsp::GetFeatureLinePnts (const string &geom_id)
std::vector< double >	vsp::GetEllipsoidCpDist (const std::vector< vec3d > &surf_pnt_vec, const vec3d &abc_rad, const vec3d &V_inf)
std::vector< vec3d >	vsp::GetAirfoilUpperPnts (const std::string &xsec_id)
std::vector< vec3d >	vsp::GetAirfoilLowerPnts (const std::string &xsec_id)
std::vector< double >	vsp::GetUpperCSTCoefs (const std::string &xsec_id)
std::vector< double >	vsp::GetLowerCSTCoefs (const std::string &xsec_id)
int	vsp::GetUpperCSTDegree (const std::string &xsec_id)
int	vsp::GetLowerCSTDegree (const std::string &xsec_id)
void	vsp::SetUpperCST (const std::string &xsec_id, int deg, const std::vector< double > &coefs)
void	vsp::SetLowerCST (const std::string &xsec_id, int deg, const std::vector< double > &coefs)
void	vsp::PromoteCSTUpper (const std::string &xsec_id)
void	vsp::PromoteCSTLower (const std::string &xsec_id)
void	vsp::DemoteCSTUpper (const std::string &xsec_id)
void	vsp::DemoteCSTLower (const std::string &xsec_id)
void	vsp::FitAfCST (const std::string &xsec_surf_id, int xsec_index, int deg)
void	vsp::WriteBezierAirfoil (const std::string &file_name, const std::string &geom_id, const double &foilsurf_u)
void	vsp::WriteSeligAirfoil (const std::string &file_name, const std::string &geom_id, const double &foilsurf_u)
std::vector< vec3d >	vsp::GetAirfoilCoordinates (const std::string &geom_id, const double &foilsurf_u)

Detailed Description

Function Documentation

ComputeXSecPnt()

vec3d vsp::ComputeXSecPnt	(	const std::string &	xsec_id,
		double	fract
	)

Compute 3D coordinate for a point on an XSec curve given the parameter value (U) along the curve

//==== Add Geom ====//
string stack_id = AddGeom( "STACK" );
 
//==== Get The XSec Surf ====//
string xsec_surf = GetXSecSurf( stack_id, 0 );
 
string xsec = GetXSec( xsec_surf, 2 );
 
double u_fract = 0.25;
 
vec3d pnt = ComputeXSecPnt( xsec, u_fract );

Parameters

[in]	xsec_id	string XSec ID
[in]	fract	double Curve parameter value (range: 0 - 1)

Returns

vec3d 3D coordinate point

ComputeXSecTan()

vec3d vsp::ComputeXSecTan	(	const std::string &	xsec_id,
		double	fract
	)

Compute the tangent vector of a point on an XSec curve given the parameter value (U) along the curve

//==== Add Geom ====//
string stack_id = AddGeom( "STACK" );
 
//==== Get The XSec Surf ====//
string xsec_surf = GetXSecSurf( stack_id, 0 );
 
string xsec = GetXSec( xsec_surf, 2 );
 
double u_fract = 0.25;
 
vec3d tan = ComputeXSecTan( xsec, u_fract );

Parameters

[in]	xsec_id	string XSec ID
[in]	fract	double Curve parameter value (range: 0 - 1)

Returns

vec3d Tangent vector

CopyXSec()

void vsp::CopyXSec	(	const std::string &	geom_id,
		int	index
	)

Copy a cross-section from the specified geometry and maintain it in memory

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Copy XSec To Clipboard
CopyXSec( sid, 1 );
 
// Paste To XSec 3
PasteXSec( sid, 3 );

See also

PasteXSec

Parameters

[in]	geom_id	string Geom ID
[in]	index	XSec index

CutXSec()

void vsp::CutXSec	(	const std::string &	geom_id,
		int	index
	)

Cut a cross-section from the specified geometry and maintain it in memory

string fid = AddGeom( "FUSELAGE", "" );             // Add Fuselage
 
//==== Insert, Cut, Paste Example ====//
InsertXSec( fid, 1, XS_ROUNDED_RECTANGLE );         // Insert A Cross-Section
 
CopyXSec( fid, 2 );                                 // Copy Just Created XSec To Clipboard
 
PasteXSec( fid, 1 );                                // Paste Clipboard
 
CutXSec( fid, 2 );                                  // Cut Created XSec

See also

PasteXSec

Parameters

[in]	geom_id	string Geom ID
[in]	index	XSec index

DemoteCSTLower()

void vsp::DemoteCSTLower

(

const std::string &

xsec_id

)

Demote the CST for the lower airfoil surface. The XSec must be of type XS_CST_AIRFOIL

See also

GetLowerCSTDegree

Parameters

[in]

xsec_id

XSec ID

DemoteCSTUpper()

void vsp::DemoteCSTUpper

(

const std::string &

xsec_id

)

Demote the CST for the upper airfoil surface. The XSec must be of type XS_CST_AIRFOIL

See also

GetUpperCSTDegree

Parameters

[in]

xsec_id

XSec ID

FitAfCST()

void vsp::FitAfCST	(	const std::string &	xsec_surf_id,
		int	xsec_index,
		int	deg
	)

Fit a CST airfoil for an existing airfoil of type XS_FOUR_SERIES, XS_SIX_SERIES, XS_FOUR_DIGIT_MOD, XS_FIVE_DIGIT, XS_FIVE_DIGIT_MOD, XS_ONE_SIX_SERIES, or XS_FILE_AIRFOIL.

Parameters

[in]	xsec_surf_id	XsecSurf ID
[in]	xsec_index	XSec index
[in]	deg	CST degree

GetAirfoilCoordinates()

std::vector< vec3d > vsp::GetAirfoilCoordinates	(	const std::string &	geom_id,
		const double &	foilsurf_u
	)

Get the untwisted unit-length 2D coordinate points for the specified airfoil

See also

WriteSeligAirfoil

Parameters

[in]	geom_id	string Geom ID
[in]	foilsurf_u	U location (range: 0 - 1) along the surface. The foil surface does not include root and tip caps (i.e. 2 section wing -> XSec0 @ u=0, XSec1 @ u=0.5, XSec2 @ u=1.0)

GetAirfoilLowerPnts()

std::vector<vec3d> vsp::GetAirfoilLowerPnts

(

const std::string &

xsec_id

)

Get the coordinate points for the lower surface of an airfoil. The XSec must be of type XS_FILE_AIRFOIL

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 1, XS_FILE_AIRFOIL );
 
string xsec = GetXSec( xsec_surf, 1 );
 
ReadFileAirfoil( xsec, "airfoil/N0012_VSP.af" );
 
array< vec3d > @low_array = GetAirfoilLowerPnts( xsec );

See also

SetAirfoilPnts

Parameters

[in]

xsec_id

string XSec ID

Returns

vector<vec3d> Vector of coordinate points for the lower airfoil surface

GetAirfoilUpperPnts()

std::vector<vec3d> vsp::GetAirfoilUpperPnts

(

const std::string &

xsec_id

)

Get the coordinate points for the upper surface of an airfoil. The XSec must be of type XS_FILE_AIRFOIL

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 1, XS_FILE_AIRFOIL );
 
string xsec = GetXSec( xsec_surf, 1 );
 
ReadFileAirfoil( xsec, "airfoil/N0012_VSP.af" );
 
array< vec3d > @up_array = GetAirfoilUpperPnts( xsec );

See also

SetAirfoilPnts

Parameters

[in]

xsec_id

string XSec ID

Returns

vector<vec3d> VectorArray of coordinate points for the upper airfoil surface

GetEllipsoidCpDist()

std::vector<double> vsp::GetEllipsoidCpDist	(	const std::vector< vec3d > &	surf_pnt_vec,
		const vec3d &	abc_rad,
		const vec3d &	V_inf
	)

Generate Analytical Solution for Potential Flow for specified ellipsoid shape at input surface points for input velocity vector. Based on Munk, M. M., 'Remarks on the Pressure Distribution over the Surface of an Ellipsoid, Moving Translationally Through a Perfect Fluid,' NACA TN-196, June 1924. Function initially created to compare VSPAERO results to theory.

const double pi = 3.14159265358979323846;
 
const int npts = 101;
 
const vec3d abc_rad = vec3d(1.0, 2.0, 3.0);
 
const double alpha = 5; // deg
 
const double beta = 5; // deg
 
const double V_inf = 100.0;
 
array < vec3d > x_slice_pnt_vec(npts);
array<double> theta_vec(npts);
 
theta_vec[0] = 0;
 
for ( int i = 1; i < npts; i++ )
{
    theta_vec[i] = theta_vec[i-1] + (2 * pi / ( npts - 1) );
}
 
for ( int i = 0; i < npts; i++ )
{
    x_slice_pnt_vec[i] = vec3d( 0, abc_rad[1] * cos( theta_vec[i] ), abc_rad[2] *sin( theta_vec[i] ) );
}
 
vec3d V_vec = vec3d( ( V_inf * cos( Deg2Rad( alpha ) ) * cos( Deg2Rad( beta ) ) ), ( V_inf * sin( Deg2Rad( beta ) ) ), ( V_inf * sin( Deg2Rad( alpha ) ) * cos( Deg2Rad( beta ) ) ) );
 
array < double > cp_dist = GetEllipsoidCpDist( x_slice_pnt_vec, abc_rad, V_vec );

See also

GetEllipsoidSurfPnts

Parameters

[in]	surf_pnt_vec	vector<vec3d> Vector of points on the ellipsoid surface to assess
[in]	abc_rad	vec3d Radius along the A (X), B (Y), and C (Z) axes
[in]	V_inf	vec3d 3D components of freestream velocity

Returns

vector<double> Vector of Cp results corresponding to each point in surf_pnt_arr

GetEllipsoidSurfPnts()

std::vector<vec3d> vsp::GetEllipsoidSurfPnts	(	const vec3d &	center,
		const vec3d &	abc_rad,
		int	u_npts = 20,
		int	w_npts = 20
	)

Generate the surface coordinate points for a ellipsoid at specified center of input radius along each axis. Based on the MATLAB function ellipsoid (https://in.mathworks.com/help/matlab/ref/ellipsoid.html).

See also

GetVKTAirfoilPnts

Parameters

[in]	center	3D location of the ellipsoid center
[in]	abc_rad	Radius along the A (X), B (Y), and C (Z) axes
[in]	u_npts	Number of points in the U direction
[in]	w_npts	Number of points in the W direction

Returns

Array of coordinates describing the ellipsoid surface

GetFeatureLinePnts()

std::vector<vec3d> vsp::GetFeatureLinePnts

(

const string &

geom_id

)

Get the points along the feature lines of a particular Geom

Parameters

[in]

geom_id

string Geom ID

Returns

Array of points along the Geom's feature lines

GetHersheyBarDragDist()

std::vector<vec3d> vsp::GetHersheyBarDragDist	(	const int &	npts,
		const double &	alpha,
		const double &	Vinf,
		const double &	span,
		bool	full_span_flag = false
	)

Get the theoretical drag (Cd) distribution for a Hershey Bar wing with unit chord length using Glauert's Method. This function was initially created to compare VSPAERO results to Lifting Line Theory. If full_span_flag is set to true symmetry is applied to the results.

// Compute theoretical lift and drag distributions using 100 points
double Vinf = 100;
 
double halfAR = 20;
 
double alpha_deg = 10;
 
int n_pts = 100;
 
array<vec3d> cl_dist_theo = GetHersheyBarLiftDist( int( n_pts ), Deg2Rad( alpha_deg ), Vinf, ( 2 * halfAR ), false );
 
array<vec3d> cd_dist_theo = GetHersheyBarDragDist( int( n_pts ), Deg2Rad( alpha_deg ), Vinf, ( 2 * halfAR ), false );

Parameters

[in]	npts	Number of points along the span to assess
[in]	alpha	Wing angle of attack (Radians)
[in]	Vinf	Freestream velocity
[in]	span	Hershey Bar full-span. Note, only half is used in the calculation
[in]	full_span_flag	Flag to apply symmetry to results (default: false)

Returns

Theoretical coefficient of drag distribution array (size = 2*npts if full_span_flag = true)

GetHersheyBarLiftDist()

std::vector<vec3d> vsp::GetHersheyBarLiftDist	(	const int &	npts,
		const double &	alpha,
		const double &	Vinf,
		const double &	span,
		bool	full_span_flag = false
	)

Get the theoretical lift (Cl) distribution for a Hershey Bar wing with unit chord length using Glauert's Method. This function was initially created to compare VSPAERO results to Lifting Line Theory. If full_span_flag is set to true symmetry is applied to the results.

// Compute theoretical lift and drag distributions using 100 points
double Vinf = 100;
 
double halfAR = 20;
 
double alpha_deg = 10;
 
int n_pts = 100;
 
array<vec3d> cl_dist_theo = GetHersheyBarLiftDist( int( n_pts ), Deg2Rad( alpha_deg ), Vinf, ( 2 * halfAR ), false );
 
array<vec3d> cd_dist_theo = GetHersheyBarDragDist( int( n_pts ), Deg2Rad( alpha_deg ), Vinf, ( 2 * halfAR ), false );

Parameters

[in]	npts	Number of points along the span to assess
[in]	alpha	Wing angle of attack (Radians)
[in]	Vinf	Freestream velocity
[in]	span	Hershey Bar full-span. Note, only half is used in the calculation
[in]	full_span_flag	Flag to apply symmetry to results

Returns

Theoretical coefficient of lift distribution array (size = 2*npts if full_span_flag = true)

GetLowerCSTCoefs()

std::vector<double> vsp::GetLowerCSTCoefs

(

const std::string &

xsec_id

)

Get the CST coefficients for the lower surface of an airfoil. The XSec must be of type XS_CST_AIRFOIL

See also

SetLowerCST

Parameters

[in]

xsec_id

string XSec ID

Returns

vector<double> Vector of CST coefficients for the lower airfoil surface

GetLowerCSTDegree()

int vsp::GetLowerCSTDegree

(

const std::string &

xsec_id

)

Get the CST degree for the lower surface of an airfoil. The XSec must be of type XS_CST_AIRFOIL

See also

SetLowerCST

Parameters

[in]

xsec_id

XSec ID

Returns

int CST Degree for lower airfoil surface

GetUpperCSTCoefs()

std::vector<double> vsp::GetUpperCSTCoefs

(

const std::string &

xsec_id

)

Get the CST coefficients for the upper surface of an airfoil. The XSec must be of type XS_CST_AIRFOIL

See also

SetUpperCST

Parameters

[in]

xsec_id

string XSec ID

Returns

vector<double> Vector of CST coefficients for the upper airfoil surface

GetUpperCSTDegree()

int vsp::GetUpperCSTDegree

(

const std::string &

xsec_id

)

Get the CST degree for the upper surface of an airfoil. The XSec must be of type XS_CST_AIRFOIL

See also

SetUpperCST

Parameters

[in]

xsec_id

string XSec ID

Returns

int CST Degree for upper airfoil surface

GetVKTAirfoilCpDist()

std::vector<double> vsp::GetVKTAirfoilCpDist	(	const double &	alpha,
		const double &	epsilon,
		const double &	kappa,
		const double &	tau,
		std::vector< vec3d >	xyz_data
	)

Get the pressure coefficient (Cp) along a Von Kármán-Trefftz airfoil of specified shape at specified points along the airfoil

const double pi = 3.14159265358979323846;
 
const int npts = 122;
 
const double alpha = 0.0;
 
const double epsilon = 0.1;
 
const double kappa = 0.1;
 
const double tau = 10;
 
array<vec3d> xyz_airfoil = GetVKTAirfoilPnts(npts, alpha, epsilon, kappa, tau*(pi/180) );
 
array<double> cp_dist = GetVKTAirfoilCpDist( alpha, epsilon, kappa, tau*(pi/180), xyz_airfoil );

See also

GetVKTAirfoilPnts

Parameters

[in]	alpha	double Airfoil angle of attack (Radians)
[in]	epsilon	double Airfoil thickness
[in]	kappa	double Airfoil camber
[in]	tau	double Airfoil trailing edge angle (Radians)
[in]	xyz_data	vector<vec3d> Vector of points on the airfoil to evaluate

Returns

vector<double> Vector of Cp values for each point in xydata

GetVKTAirfoilPnts()

std::vector<vec3d> vsp::GetVKTAirfoilPnts	(	const int &	npts,
		const double &	alpha,
		const double &	epsilon,
		const double &	kappa,
		const double &	tau
	)

Get the 2D coordinates an input number of points along a Von K�rm�n-Trefftz airfoil of specified shape

const double pi = 3.14159265358979323846;
 
const int npts = 122;
 
const double alpha = 0.0;
 
const double epsilon = 0.1;
 
const double kappa = 0.1;
 
const double tau = 10;
 
array<vec3d> xyz_airfoil = GetVKTAirfoilPnts(npts, alpha, epsilon, kappa, tau*(pi/180) );
 
array<double> cp_dist = GetVKTAirfoilCpDist( alpha, epsilon, kappa, tau*(pi/180), xyz_airfoil );

Parameters

[in]	npts	Number of points along the airfoil to return
[in]	alpha	Airfoil angle of attack (Radians)
[in]	epsilon	Airfoil thickness
[in]	kappa	Airfoil camber
[in]	tau	Airfoil trailing edge angle (Radians)

Returns

Array of points on the VKT airfoil (size = npts)

GetXSecHeight()

double vsp::GetXSecHeight

(

const std::string &

xsec_id

)

Get the height of an XSec. Note that POINT type XSecs have a width and height of 0, regardless of what width and height it is set to.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
string xsec = GetXSec( xsec_surf, GetNumXSec( xsec_surf ) - 2 ); // Get 2nd to last XSec
 
SetXSecWidthHeight( xsec, 3.0, 6.0 );
 
if ( abs( GetXSecHeight( xsec ) - 6.0 ) > 1e-6 )        { Print( "---> Error: API Get/Set Width " ); }

See also

SetXSecHeight

Parameters

[in]

xsec_id

XSec ID

Returns

Xsec height

GetXSecParm()

std::string vsp::GetXSecParm	(	const std::string &	xsec_id,
		const std::string &	name
	)

Get a specific Parm ID from an Xsec

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, GetNumXSec( xsec_surf ) - 1, XS_ROUNDED_RECTANGLE );
 
string xsec = GetXSec( xsec_surf, GetNumXSec( xsec_surf ) - 1 );
 
string wid = GetXSecParm( xsec, "RoundedRect_Width" );
 
if ( !ValidParm( wid ) )                            { Print( "---> Error: API GetXSecParm " ); }

Parameters

[in]	xsec_id	XSec ID
[in]	name	Parm name

Returns

Parm ID

GetXSecParmIDs()

std::vector<std::string> vsp::GetXSecParmIDs

(

const std::string &

xsec_id

)

Get all Parm IDs for specified XSec Parm Container

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
string xsec = GetXSec( xsec_surf, GetNumXSec( xsec_surf ) - 1 );
 
array< string > @parm_array = GetXSecParmIDs( xsec );
 
if ( parm_array.size() < 1 )                        { Print( "---> Error: API GetXSecParmIDs " ); }

Parameters

[in]

xsec_id

XSec ID

Returns

Array of Parm IDs

GetXSecShape()

int vsp::GetXSecShape

(

const std::string &

xsec_id

)

Get the shape of an XSec

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
ChangeXSecShape( xsec_surf, 1, XS_EDIT_CURVE );
 
string xsec = GetXSec( xsec_surf, 1 );
 
if ( GetXSecShape( xsec ) != XS_EDIT_CURVE ) { Print( "ERROR: GetXSecShape" ); }

See also

XSEC_CRV_TYPE

Parameters

[in]

xsec_id

XSec ID

Returns

XSec type enum (i.e. XS_ELLIPSE)

GetXSecWidth()

double vsp::GetXSecWidth

(

const std::string &

xsec_id

)

Get the width of an XSec. Note that POINT type XSecs have a width and height of 0, regardless of what width and height it is set to.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
string xsec = GetXSec( xsec_surf, GetNumXSec( xsec_surf ) - 2 ); // Get 2nd to last XSec
 
SetXSecWidthHeight( xsec, 3.0, 6.0 );
 
if ( abs( GetXSecWidth( xsec ) - 3.0 ) > 1e-6 )        { Print( "---> Error: API Get/Set Width " ); }

See also

SetXSecWidth

Parameters

[in]

xsec_id

XSec ID

Returns

Xsec width

InsertXSec()

void vsp::InsertXSec	(	const std::string &	geom_id,
		int	index,
		int	type
	)

Insert a cross-section of particular type to the specified geometry after the given index

string wing_id = AddGeom( "WING" );
 
//===== Add XSec ====//
InsertXSec( wing_id, 1, XS_SIX_SERIES );

See also

XSEC_CRV_TYPE

Parameters

[in]	geom_id	string Geom ID
[in]	index	XSec index
[in]	type	XSec type enum (i.e. XS_GENERAL_FUSE)

PasteXSec()

void vsp::PasteXSec	(	const std::string &	geom_id,
		int	index
	)

Paste the cross-section currently held in memory to the specified geometry

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Copy XSec To Clipboard
CopyXSec( sid, 1 );
 
// Paste To XSec 3
PasteXSec( sid, 3 );

See also

CutXSec, CopyXSec

Parameters

[in]	geom_id	string Geom ID
[in]	index	XSec index

PromoteCSTLower()

void vsp::PromoteCSTLower

(

const std::string &

xsec_id

)

Promote the CST for the lower airfoil surface. The XSec must be of type XS_CST_AIRFOIL

See also

GetLowerCSTDegree

Parameters

[in]

xsec_id

XSec ID

PromoteCSTUpper()

void vsp::PromoteCSTUpper

(

const std::string &

xsec_id

)

Promote the CST for the upper airfoil surface. The XSec must be of type XS_CST_AIRFOIL

See also

GetUpperCSTDegree

Parameters

[in]

xsec_id

XSec ID

ReadFileAirfoil()

void vsp::ReadFileAirfoil	(	const std::string &	xsec_id,
		const std::string &	file_name
	)

Read in XSec shape from airfoil file and set to the specified XSec. The XSec must be of type XS_FILE_AIRFOIL. Airfoil files may be in Lednicer or Selig format with *.af or *.dat extensions.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 1, XS_FILE_AIRFOIL );
 
string xsec = GetXSec( xsec_surf, 1 );
 
ReadFileAirfoil( xsec, "airfoil/N0012_VSP.af" );

Parameters

[in]	xsec_id	XSec ID
[in]	file_name	Airfoil XSec file name

ReadFileXSec()

std::vector<vec3d> vsp::ReadFileXSec	(	const std::string &	xsec_id,
		const std::string &	file_name
	)

Read in XSec shape from fuselage (*.fsx) file and set to the specified XSec. The XSec must be of type XS_FILE_FUSE.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 2, XS_FILE_FUSE );
 
string xsec = GetXSec( xsec_surf, 2 );
 
array< vec3d > @vec_array = ReadFileXSec( xsec, "TestXSec.fxs" );

Parameters

[in]	xsec_id	XSec ID
[in]	file_name	Fuselage XSec file name

Returns

Array of coordinate points read from the file and set to the XSec

ResetXSecSkinParms()

void vsp::ResetXSecSkinParms

(

const std::string &

xsec_id

)

Reset all skinning Parms for a specified XSec. Set top, bottom, left, and right strengths, slew, angle, and curvature to 0. Set all symmetry and equality conditions to false.

string fid = AddGeom( "FUSELAGE", "" );             // Add Fuselage
 
string xsec_surf = GetXSecSurf( fid, 0 );           // Get First (and Only) XSec Surf
 
int num_xsecs = GetNumXSec( xsec_surf );
 
string xsec = GetXSec( xsec_surf, 1 );
 
SetXSecTanAngles( xsec, XSEC_BOTH_SIDES, 0.0 );       // Set Tangent Angles At Cross Section
SetXSecContinuity( xsec, 1 );                       // Set Continuity At Cross Section
 
ResetXSecSkinParms( xsec );

Parameters

[in]

xsec_id

string XSec ID

SetAirfoilLowerPnts()

void vsp::SetAirfoilLowerPnts	(	const std::string &	xsec_id,
		const std::vector< vec3d > &	low_pnt_vec
	)

Set the lower points for an airfoil. The XSec must be of type XS_FILE_AIRFOIL.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 1, XS_FILE_AIRFOIL );
 
string xsec = GetXSec( xsec_surf, 1 );
 
ReadFileAirfoil( xsec, "airfoil/N0012_VSP.af" );
 
array< vec3d > @low_array = GetAirfoilLowerPnts( xsec );
 
for ( int i = 0 ; i < int( low_array.size() ) ; i++ )
{
    low_array[i].scale_y( 0.5 );
}
 
SetAirfoilUpperPnts( xsec, low_array );

Parameters

[in]	xsec_id	XSec ID
[in]	low_pnt_vec	Array of points defining the lower surface of the airfoil

SetAirfoilPnts()

void vsp::SetAirfoilPnts	(	const std::string &	xsec_id,
		const std::vector< vec3d > &	up_pnt_vec,
		const std::vector< vec3d > &	low_pnt_vec
	)

Set the upper and lower points for an airfoil. The XSec must be of type XS_FILE_AIRFOIL.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 1, XS_FILE_AIRFOIL );
 
string xsec = GetXSec( xsec_surf, 1 );
 
ReadFileAirfoil( xsec, "airfoil/N0012_VSP.af" );
 
array< vec3d > @up_array = GetAirfoilUpperPnts( xsec );
 
array< vec3d > @low_array = GetAirfoilLowerPnts( xsec );
 
for ( int i = 0 ; i < int( up_array.size() ) ; i++ )
{
    up_array[i].scale_y( 2.0 );
 
    low_array[i].scale_y( 0.5 );
}
 
SetAirfoilPnts( xsec, up_array, low_array );

Parameters

[in]	xsec_id	XSec ID
[in]	up_pnt_vec	Array of points defining the upper surface of the airfoil
[in]	low_pnt_vec	Array of points defining the lower surface of the airfoil

SetAirfoilUpperPnts()

void vsp::SetAirfoilUpperPnts	(	const std::string &	xsec_id,
		const std::vector< vec3d > &	up_pnt_vec
	)

Set the upper points for an airfoil. The XSec must be of type XS_FILE_AIRFOIL.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 1, XS_FILE_AIRFOIL );
 
string xsec = GetXSec( xsec_surf, 1 );
 
ReadFileAirfoil( xsec, "airfoil/N0012_VSP.af" );
 
array< vec3d > @up_array = GetAirfoilUpperPnts( xsec );
 
for ( int i = 0 ; i < int( up_array.size() ) ; i++ )
{
    up_array[i].scale_y( 2.0 );
}
 
SetAirfoilUpperPnts( xsec, up_array );

Parameters

[in]	xsec_id	XSec ID
[in]	up_pnt_vec	Array of points defining the upper surface of the airfoil

SetLowerCST()

void vsp::SetLowerCST	(	const std::string &	xsec_id,
		int	deg,
		const std::vector< double > &	coefs
	)

Set the CST degree and coefficients for the lower surface of an airfoil. The number of coefficients should be one more than the CST degree. The XSec must be of type XS_CST_AIRFOIL

See also

GetLowerCSTDegree, GetLowerCSTCoefs

Parameters

[in]	xsec_id	string XSec ID
[in]	deg	int CST degree of lower airfoil surface
[in]	coefs	vector<double> Vector of CST coefficients for the lower airfoil surface

SetUpperCST()

void vsp::SetUpperCST	(	const std::string &	xsec_id,
		int	deg,
		const std::vector< double > &	coefs
	)

Set the CST degree and coefficients for the upper surface of an airfoil. The number of coefficients should be one more than the CST degree. The XSec must be of type XS_CST_AIRFOIL

See also

GetUpperCSTDegree, GetUpperCSTCoefs

Parameters

[in]	xsec_id	string XSec ID
[in]	deg	int CST degree of upper airfoil surface
[in]	coefs	vector<double> Vector of CST coefficients for the upper airfoil surface

SetXSecContinuity()

void vsp::SetXSecContinuity	(	const std::string &	xsec_id,
		int	cx
	)

Set C-type continuity enforcement for a particular XSec

string fid = AddGeom( "FUSELAGE", "" );             // Add Fuselage
 
string xsec_surf = GetXSecSurf( fid, 0 );           // Get First (and Only) XSec Surf
 
int num_xsecs = GetNumXSec( xsec_surf );
 
for ( int i = 0 ; i < num_xsecs ; i++ )
{
    string xsec = GetXSec( xsec_surf, i );
 
    SetXSecContinuity( xsec, 1 );                       // Set Continuity At Cross Section
}

Parameters

[in]	xsec_id	string XSec ID
[in]	cx	int Continuity level (0, 1, or 2)

SetXSecCurvatures()

void vsp::SetXSecCurvatures	(	const std::string &	xsec_id,
		int	side,
		double	top,
		double	right,
		double	bottom,
		double	left
	)

Set curvatures for the specified XSec

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
// Flatten ends
int num_xsecs = GetNumXSec( xsec_surf );
 
for ( int i = 0 ; i < num_xsecs ; i++ )
{
    string xsec = GetXSec( xsec_surf, i );
 
    SetXSecCurvatures( xsec, XSEC_BOTH_SIDES, 0.2 );  // Set Tangent Strengths At Cross Section
}

See also

XSEC_SIDES_TYPE

Parameters

[in]	xsec_id	XSec ID
[in]	side	Side type enum (i.e. XSEC_BOTH_SIDES)
[in]	top	Top curvature
[in]	right	Right curvature
[in]	bottom	Bottom curvature
[in]	left	Left curvature

SetXSecHeight()

void vsp::SetXSecHeight	(	const std::string &	xsec_id,
		double	h
	)

Set the height of an XSec. Note that POINT type XSecs have a width and height of 0, regardless of what is input to SetXSecHeight.

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
// Identify XSec 2
string xsec_2 = GetXSec( xsec_surf, 2 );
 
SetXSecHeight( xsec_2, 1.5 );

See also

GetXSecHeight

Parameters

[in]	xsec_id	XSec ID
[in]	h	Xsec height

SetXSecPnts()

void vsp::SetXSecPnts	(	const std::string &	xsec_id,
		std::vector< vec3d > &	pnt_vec
	)

Set the coordinate points for a specific XSec. The XSec must be of type XS_FILE_FUSE.

// Add Fuselage Geom
string fuseid = AddGeom( "FUSELAGE", "" );
 
string xsec_surf = GetXSecSurf( fuseid, 0 );
 
ChangeXSecShape( xsec_surf, 2, XS_FILE_FUSE );
 
string xsec = GetXSec( xsec_surf, 2 );
 
array< vec3d > @vec_array = ReadFileXSec( xsec, "TestXSec.fxs" );
 
if ( vec_array.size() > 0 )
{
    vec_array[1] = vec_array[1] * 2.0;
    vec_array[3] = vec_array[3] * 2.0;
 
    SetXSecPnts( xsec, vec_array );
}

Parameters

[in]	xsec_id	string XSec ID
[in]	pnt_vec	vector<vec3d> Vector of XSec coordinate points

SetXSecTanAngles()

void vsp::SetXSecTanAngles	(	const std::string &	xsec_id,
		int	side,
		double	top,
		double	right,
		double	bottom,
		double	left
	)

Set the tangent angles for the specified XSec

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
int num_xsecs = GetNumXSec( xsec_surf );
 
for ( int i = 0 ; i < num_xsecs ; i++ )
{
    string xsec = GetXSec( xsec_surf, i );
 
    SetXSecTanAngles( xsec, XSEC_BOTH_SIDES, 10.0 );       // Set Tangent Angles At Cross Section
}

See also

XSEC_SIDES_TYPE

Parameters

[in]	xsec_id	string XSec ID
[in]	side	int Side type enum (i.e. XSEC_BOTH_SIDES)
[in]	top	double Top angle (degrees)
[in]	right	double Right angle (degrees)
[in]	bottom	double Bottom angle (degrees)
[in]	left	double Left angle (degrees)

SetXSecTanSlews()

void vsp::SetXSecTanSlews	(	const std::string &	xsec_id,
		int	side,
		double	top,
		double	right,
		double	bottom,
		double	left
	)

Set the tangent slew angles for the specified XSec

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
int num_xsecs = GetNumXSec( xsec_surf );
 
for ( int i = 0 ; i < num_xsecs ; i++ )
{
    string xsec = GetXSec( xsec_surf, i );
 
    SetXSecTanSlews( xsec, XSEC_BOTH_SIDES, 5.0 );       // Set Tangent Slews At Cross Section
}

See also

XSEC_SIDES_TYPE

Parameters

[in]	xsec_id	XSec ID
[in]	side	Side type enum (i.e. XSEC_BOTH_SIDES)
[in]	top	Top angle (degrees)
[in]	right	Right angle (degrees)
[in]	bottom	Bottom angle (degrees)
[in]	left	Left angle (degrees)

SetXSecTanStrengths()

void vsp::SetXSecTanStrengths	(	const std::string &	xsec_id,
		int	side,
		double	top,
		double	right,
		double	bottom,
		double	left
	)

Set the tangent strengths for the specified XSec

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
// Flatten ends
int num_xsecs = GetNumXSec( xsec_surf );
 
for ( int i = 0 ; i < num_xsecs ; i++ )
{
    string xsec = GetXSec( xsec_surf, i );
 
    SetXSecTanStrengths( xsec, XSEC_BOTH_SIDES, 0.8 );  // Set Tangent Strengths At Cross Section
}

See also

XSEC_SIDES_TYPE

Parameters

[in]	xsec_id	XSec ID
[in]	side	Side type enum (i.e. XSEC_BOTH_SIDES)
[in]	top	Top strength
[in]	right	Right strength
[in]	bottom	Bottom strength
[in]	left	Left strength

SetXSecWidth()

void vsp::SetXSecWidth	(	const std::string &	xsec_id,
		double	w
	)

Set the width of an XSec. Note that POINT type XSecs have a width and height of 0, regardless of what is input to SetXSecWidth.

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
// Identify XSec 2
string xsec_2 = GetXSec( xsec_surf, 2 );
 
SetXSecWidth( xsec_2, 1.5 );

See also

GetXSecWidth

Parameters

[in]	xsec_id	XSec ID
[in]	w	Xsec width

SetXSecWidthHeight()

void vsp::SetXSecWidthHeight	(	const std::string &	xsec_id,
		double	w,
		double	h
	)

Set the width and height of an XSec. Note, if the XSec is an EDIT_CURVE type and PreserveARFlag is true, the input width value will be ignored and instead set from on the input height and aspect ratio. Use SetXSecWidth and SetXSecHeight directly to avoid this.

// Add Stack
string sid = AddGeom( "STACK", "" );
 
// Get First (and Only) XSec Surf
string xsec_surf = GetXSecSurf( sid, 0 );
 
// Identify XSec 2
string xsec_2 = GetXSec( xsec_surf, 2 );
 
SetXSecWidthHeight( xsec_2, 1.5, 1.5 );

See also

SetXSecWidth, SetXSecHeight

Parameters

[in]	xsec_id	XSec ID
[in]	w	Xsec width
[in]	h	Xsec height

WriteBezierAirfoil()

void vsp::WriteBezierAirfoil	(	const std::string &	file_name,
		const std::string &	geom_id,
		const double &	foilsurf_u
	)

Write out the untwisted unit-length 2D Bezier curve for the specified airfoil in custom *.bz format. The output will describe the analytical shape of the airfoil. See BezierAirfoilExample.m and BezierCtrlToCoordPnts.m for examples of discretizing the Bezier curve and generating a Selig airfoil file.

//==== Add Wing Geometry and Set Parms ====//
string wing_id = AddGeom( "WING", "" );
 
const double u = 0.5; // export airfoil at mid span location
 
//==== Write Bezier Airfoil File ====//
WriteBezierAirfoil( "Example_Bezier.bz", wing_id, u );

Parameters

[in]	file_name	Airfoil (*.bz) output file name
[in]	geom_id	string Geom ID
[in]	foilsurf_u	U location (range: 0 - 1) along the surface. The foil surface does not include root and tip caps (i.e. 2 section wing -> XSec0 @ u=0, XSec1 @ u=0.5, XSec2 @ u=1.0)

WriteSeligAirfoil()

void vsp::WriteSeligAirfoil	(	const std::string &	file_name,
		const std::string &	geom_id,
		const double &	foilsurf_u
	)

Write out the untwisted unit-length 2D coordinate points for the specified airfoil in Selig format. Coordinate points follow the on-screen wire frame W tessellation.

//==== Add Wing Geometry and Set Parms ====//
string wing_id = AddGeom( "WING", "" );
 
const double u = 0.5; // export airfoil at mid span location
 
//==== Write Selig Airfoil File ====//
WriteSeligAirfoil( "Example_Selig.dat", wing_id, u );

See also

GetAirfoilCoordinates

Parameters

[in]	file_name	Airfoil (*.dat) output file name
[in]	geom_id	string Geom ID
[in]	foilsurf_u	U location (range: 0 - 1) along the surface. The foil surface does not include root and tip caps (i.e. 2 section wing -> XSec0 @ u=0, XSec1 @ u=0.5, XSec2 @ u=1.0)