Interpretacions of lines labels in lines.txt

Figure 1: How to work with the program
Figure 2: Airfoils definition
Figure 3: Washin
Figure 4: Axes and coordinates
Figure 5. Miribs definition
Figure 6. Parameter of rotation in "ss" paragliders
Figure 7. Parameter delta of rib forced vertical displacement
Figure 8. Hole type 1, ellipse
Figure 9. Hole type 2, ellipse or circle with central strip
Figure 10. Hole type 3 triangle
Figure 11. Skin tension
Figure 12. Ripstop elasticity
Figure 13. Sewing corrections
Figure 14: General AoA estimation
Figure 15: Suspension lines matrix
Figure 16. Brake distribution
Figure 17: Ramifications length
Figure 18. Mini-rib 1 (horizontal strap)
Figure 19. Mini-rib 2 (V-rib)
Figure 20. Mini-rib 3 (full V-rib)
Figure 21. Mini-rib 4 (VH-rib)
Figure 22. Full continous V-ribs type 5 using parabolic holes
Figure 23. Full continous V-ribs type 5 using elliptical holes
Figure 24. V-rib type 6 general diagonal
Figure 25. Extrados colors
Figure 26. Mark types
Figure 27. Joncs definition
Figure 28. Mylar definition
Figure 29. Tabs definition
Figure 30. Glue vents
Figure 31. Vents types
Figure 32. Special wingtips
Figure 33. Calage variation principe
Figure 34. Calage variation cases
Figure 35. Calage graphic
Figure 36. 3D shaping

LEparagliding is very "cryptic" to use, "FORTRAN style", but very powerfull. FORTRAN is a programming language aimed at numerical calculation, which means FORmula TRANslation. It is a language that allows us to accurately translate the ideas of geometry and mathematics to a code that produces amazing graphical and numerical results.

File program source code, written in language "GNU Fortran 77". This file is not necessary for the end user. Is included for developers who want to make modifications, improvements and extensions to the code, or for students. These changes are completely free under the principles and conditions of the GNU General Public License 3.0 (http://www.gnu.org) which is distributed the program.

    1. Pre-process


    2. Edit data file

    Descibed below in detail. Complete sections 1 to 31. It is the most important operation, and the overall design of the glider itself

    3. Program execution (seconds)

   GNU/Linux: run ./lep-X.XX.out in a terminal

    Windows: execute lep-X.XX.exe including one or more compatible cygwin .dll's in the same directory.

    Mac OSX: compile sorce code in a terminal: " f77 leparagliding.f" and run "./lep-X.XX.out" in terminal as in linux
   (compiler name will be f77, g77, gfortran, or equivalent). Not tested yet.

    4. Viewing the drawings (CAD)

  The program CAD displays the results dxf file. Please use 'zoom_extension' command.

    5. Iteration from stage 1. to achieve the desired layout.

    6. Post-process CAD

Designing the paraglider is simplified to editing the file leparagliding.txt either creating it from scratch or by editing an existing model.

All lines that begin with the symbol "*" are comments that are not used by the program, although you must maintain it to keep the sequence of reading.
It is not allowed to add blank lines.
The main units planned for the data file are centimeters (cm), except sewing allowances in section 6, and some values in section 20 and 21 will be expressed in mm. Optionally, you could use inches and tenths of inches, but this has not been tested ever.

Next, and by section, we define the parameters to enter in the data file. Only are explained the line to complete, because the lines that begin with the asterisk symbol * are comments that should be maintained as are, so that the reading order is right.

First, it indicates the type of data to enter (integer, real , text, or boolean (1 or 0)). Then, following the ":" , indicates the object's data to write. It is essential using the sample file leparagliding.txt to understand. The order, data type, and number of rows is essential for a correct reading of the data file.

text  :   Brand name (between "  ")
text  :  Wing name (between "  ")
real  :  Drawing scale (1.0 usual value)
real  :   Wing scale (1.0 usual value)
integer :    Cells number
integer :   Ribs number
real, integer, real : Maximum torsion angle (washin) between central airfoil and tips, an integer parameter set to 0-1- 2, and a real number for the angle of attack in the center used only in case "2".

If the integer parameter is set to "0" the washin will be done manually.  (Figure 3).
If the integer parameter is set to "1" then washin will be done proportinal to the chord, being maximun and positive at the tip, using only the first real.
If the integer parameter is set to  "2", then automatic washin angles are set from center airfoil to wingtip. The first real is the washin in wingtip, then set "2", and the last real is the washin in the central airfoil.

Example about how to use: Below line 21 in leparagliding.txt data file:

* Alpha max and parameter
3.5   2  -1.0

- First number "3.5" is the angle of attack (degres) in wingtip airfoil
- Second number "2" is a control parameter that means case "2", ie, add new number indicating the angle of attack of the central airfoil
- Third number "-1.0" is the angle of attack (degres) of the central airfoil

The distribution angles of attack is made proportional to the wing chord (similar to case "1"). See "lep-out.txt" to view the result.

text, boolean : Paraglider type "ds", "ss", or "pc", and parameter set to 0 or 1. If 1 then leading edge triangles will be no rotated (only ss paragliders)
integer + 10 reals:

integer : rib number
real : rib X coordinate
real : Y coordinate of the leading edge
real : Y coordinate of the trailing edge
real : X' coordinate of the rib in its final position in space
real : Z coordinate of the rib in its final position in space
real : the angle "beta" of the rib to the vertical (degres)
real : RP percentage of chord to be held on the relative torsion of the airfoils
real : washin in degrees defined manually (if parameter is set to "0")

And since version 3.15z, you MUST add two additional parameters:

real : angle of rotation of the profiles with respect to a vertical axis Z (degrees).
real : numeric value expressed as a percentage of the chord, where to place the vertical axis of rotation of the profiles

Instructions for selecting the type of paraglider (parameters "ds" "ss" "pc" listed above):

"ds": means that the design and calculation parameters are adjusted to create paragliders and parachute of double surface airfoils (intrados and extrados)
"ss":  means that the design and calculation parameters are adjusted to create single skin paragliders and parachutes, Surfaces corresponding to the intrados are not draw. But it is not enough to indicate this parameter to create single skin paraglider. It is necessary to define an special intrados sawtooth profile (or parabolic shaped), so that the vertices of the triangles are located exactly at the point where% is defined the anchor points. As a general rule, we use covers of the air intakes, as part of the sigle skin profile.
"pc": means that the design and calculation parameters are adjusted to create parachutes using double surface airfoils (intrados and extrados).

Maximun alloved number of ribs is 100 per side (200 ribs or 199 cells).


Figure 5.  Only in "ss" paragliders, the parameter set to 0 or 1. If "1" then leading edge triangles will be no rotated. Control over specified ribs will be done using a real parameter 0.0 or 1.0 in last column of section 2, as explained below.

integer : Number of rib
text : Name the file containing the airfoil assigned to that rib
real : Percentage of chord start of the air inlet
real : Percentage of chord end of the air  inlet
boolean : Value 1 or 0 to create closed cells, at the left of rib ("0" indicates closed-cell, "1" open)
real : Displacement in cm of the rib perpendicular to the chord, and in the plane of the rib itself. Serves to improve the position of the ribs without suspension lines. Value is usually 0
real: Relative weight of the chord, in relation to the load. Value is usually 1.
real: It has two meanings:

                Figure 6. Miribs definition in lep  <  2.50 (since lep-2.50 minirib "i" was defined at LEFT, between "i-1" an "i")

Note: init and end points of the air openings are not fully implemented yet in the program, and is in the profile itself obliged to include it means of the integer numbers that describe the end of the top surface and the beginning of the intrados (in each airfoil).

MIDDLE UNLOADED RIBS: Added the possibility of using "middle unloaded ribs". Very easy to use: In section "2. AIRFOILS" at the last column use the parameter "100", means to place a complete unloaded rib in the middle of the panel, and the left corresponding rib. Similarly, as defined in the mini-ribs. But the parameter "100" activates a new specific programation. New plan numbered "1-6" with the new middle ribs numbered and marked. These ribs have been reformatted to achieve a perfect match with high precision, with the corresponding panels. In the center of the panels, are marked equidistant points in correspondence with the middle unloaded ribs. In addition, in the 2D-planform (plan "1-1"), also drawn in gray new ribs. Planned to draw in 3D (for reference) but not yet done. Important: To define holes in the ribs (elliptical or circles), add in section "4. AIRFOIL HOLES" a new hole type "11" that is defined exactly as the type "1" (hole type "1" and type "11" are exactly the same but the type "11" used exclusively by the middle unloaded ribs). In this case the initial rib number and end rib number with holes type "11" should be the same, and greater than the maximum number of ribs on one side, for example, use "50" . See the attached example "leparagliding.txt". All new programation in section 9.9 of the source code.

- "Mini-ribs" are redefined, and now in section "2. AIRFOILS" at the last column, if you use the parameter "15", means to place a 15% mini-rib in the middle of the panel, and at the LEFT of the corresponding rib. Previously (lep < 2.50), mini-rib it was placed on the RIGHT. But it is better set at the left, so you can specify a minirib the center of the wing (Mini-rib specified in the left first rib). And this is consistent with the new middle unloaded ribs.

- Applied little optional displacement (to the center of the wing) in the points marking the position of the miniribs. Third parameter in the line of section "7. MARKS" of the datafile. Before, this displacement was set to default to zero.

integer : Number of rib
integer : Number of anchors in the rib
real : Anchor position A as% of rib
real : Anchor position B as% of rib
real : Anchor position C as% of the rib
real : Anchor position D as% of rib
real : Anchor position E as% of rib
real : Anchor position F as% of rib

integer : Number of configurations of lightening
integer : Initial rib for first lightening configuration
integer : Final rib for first lightening configuration
integer : Number of holes for the first lightening configuration

integer : 1

real : Distance from LE to hole center in% chord
real : Distance from the center of hole to the chord line in% of chord
real : Horizontal axis of the ellipse as% of chord
real : Ellipse vertical axis as% of chord
real : Rotation angle of the ellipse
real : 0. (not used)

real : 0. (not used)
real : 0. (not used)


Figure 8. Hole type 1, ellipse

integer : 2

real : Distance from LE to hole center in% chord
real : Distance from the center of hole to the chord line in% of chord
real : Horizontal axis of the ellipse as% of chord
real : Ellipse vertical axis as% of chord
real : Rotation angle of the ellipse
real : central strip width

real : 0. (not used)
real : 0. (not used)

Figure 9. Hole type 2, ellipse or circle with central strip

Not use holes type 2 beacuse yet no implemented !

integer : 3

real : Distance from LE to triangle in% chord
real : Distance from the center of the triangle corner to the chord line in% of chord
real : Traingle base as% of chord
real : Triangle heigth as% of chord
real : Rotation angle of the base
real : Radius of the smoothed corners

real : 0. (not used)
real : 0. (not used)

Figure 10. Hole type 3 triangle

integer : 4
real : x Distance from LE to main rectangle corner in % of chord
real : y Distance from chord line to main rectangle corner in % of chord
real : a rectangle width as % of chord
real : b rectangle heigth as % of chord
real : Rotation angle (degrees) relative to chord line
real : Radius (%) of the smoothed corners
real : 0. (not used)
real : 0. (not used)

The main vertex or reference vertex of the rectangle is the bottom left.
If the width value (a) is positive, the rectangle is drawn to the right of the main vertex.
If the value of (a) is negative, then the rectangle is drawn to the left. Similar to the case of triangular holes.



Image 10.1 Parameters for hole type 4 (rectangular)

integer : Initial rib for second lightening configuration
integer : Final rib for second lightening configuration
integer : Number of holes for the second lightening configuration

Definition of each hole in a horizontal line, as before.

And so on... (repeat pattern for all types of lightening configurations)

real : Distance in% of chord on the leading edge of extrados
real : Extrados over-wide corresponding in % of chord
real : Distance in% of chord on trailing edge
real : Intrados over-wide corresponding in% of chord

 real : 0.0114 (strain in mini-ribs).

And the explanation:

When three panels are sewn at the same time, with different curvatures to side... problems may arise:

The left panel (i="izquierda") has a concave curvature, while the right panel (d="derecha") has a convex curvature.

The lengths of seam lines (line dashed) should be exactly the same. However, the outer edge of the fabric, which is 15 mm from the seam line, is shorter in the left case (inner radius) than the right (outer radius). The program calculates the difference in length of the leading edge in the area of "np" points od airfoil of greatest curvature from air inlet (np defined by user).

With the calculated length difference (1d2d-1i2i), the program modifies the plan shape of the left panel, extending its inner side. Thus, when the seam is made, there are fewer problems ...

The second control parameter, "k" between 0. and 1. is the coefficient to be applied to the difference (1d2d-1i2i). Then 0.0 = no effect. 1.0 = total effect. Then sewing corrections:

integer, real : Number of points np, k coeficient 0.0 to 1.0

3 reals : Edge seam (mm) in upper panels,  LE, TE
3 reals : Edge seam (mm) in lower panels, LE, TE
real : Edge seam (mm) in ribs
real : Edge seam (mm) in V-ribs

real, real, real : marks spacing, point radius, point displacement

real : Finesse goal, according to the general proportions of the wing.

real : Position of the wing center of pressure estimated as % of central cord

real : Calage in% (distance from the leading edge point to the perpendicular to the central chord from the pilot position)

real : Riser basic length

real : Basic length of lines (maillons - sail)

real : Separation between main carabiners

integer : Control parameter with the following meanings

integer : Line plans number (2,3,4...)

integer : Paths number for first plan

11 integers : i1, i2, i3, i4, i5, i6, i7, i8 ,i9, i19, i11 Ramifications and levels

integer : Paths number for second plan

real : brake lenght

integer : number of paths brake plane

11 integers : i1, i2, i3, i4, i5, i6, i7, i8 ,i9, i10, i11 Ramifications and levels

NOTE:  i11 indicates rib number "i", where anchor the top line of the brakes. This number, usually an integer. Nevertheless, some versions ago was added an interesting feature. Is possible define a decimal which means the displacement of the anchoring point between the rib "i" and the rib and "i+1". For example, 8.4 means anchor the line in the trailing edge, between rib 8 and 9, and 40% from the rib 8.

4 real : s1, s2, s3, s4, s5 (lengths along vault and from center wing)

4 real : d1, d2, d3, d4, d5 (lengths increments in brake line)

integer, real :  3 , Distance branching from third ramification to sail (l2)

integer, real, real :  4, Distance branching third to sail (l3), Distance beginning of fourth branching to sail (l2)

integer, real :  3, Distance beginning of third brake branch to sail (l2)

integer, real, real : 4, Distance beginning of third brake branch to sail (l3), Distance brakes start fourth branching to sail (l2)

integer : mini-ribs number

real, real : x-spacing, y-spacing (when drawing mini-ribs)

integer, integer, integer, integer, integer, integer, real, real real, real, real :

Parameters:

n = number of V-rib (consecutive order)
6 = define V-rib "type 6"
i = number of initial rib
x1 = starting position as a percentage of the chord of the profile
h1 = initial height in percent of the local thickness profile
r1 = radius backwards (cm)
r1- = radius forward (cm)
i +1 = number of final rib
x2 = starting position as a percentage of the chord of the profile
h2 = initial height in percent of the local thickness profile
r2+ = radius backwards (cm)
r2- = radius forward (cm)

Type 6 uses 12 parameters, while the other V-ribs types, use only 10 parameters. This is no problem. The program can read the data file correctly. Simply, interpret the scheme. Try and see the results. Type-6 is now working and fully implemented.

Very important: The pieces "Type 6", must be defined consecutively, and line by line. With the following order: From the leading edge to the trailing edge, and from the center of the wing, to the wingtip. That is, first define all the pieces consecutively in rib number "i", before defining pieces in a rib greater than "i".

integer : number of ribs with marks

integer, integer : first rib number, number of marks

integer, real, 0. : first mark, distance % from TE, 0.

integer, real, 0. : second mark, distance % from TE, 0.
                                ...

integer, integer : second rib number, number of marks

integer, real, 0. : first mark, distance % from TE, 0.

integer, real, 0. : second mark, distance % from TE, 0.
                                ...
and so on...

1
1    1
1    0.    0.

integer : number of points

real, real : x-coordinate % of chord, y coordinate % of chord (first point)
                  ....
real, real : x-coordinate % of chord, y coordinate % of chord (last point)

real : load in flight (kg)

real, real : % load distribution in 2 lines rib

real, real, real : % load distribution in 3 lines rib

real, real, real, real : % load distribution in 4 lines rib

real, real, real, real, real :  % load distribution in 5 lines rib

integer, real, real, real, real :  p, d1, d2, d3 where

This section allows the user to choose some layers names in the DXF files. To facilitate the edition and modification of DXF files. In version 2.75 only the layers "points" "circles" and "triangles" are functional.

By lines, and regardless of the lines beginning with * which are comments or notes for help:

By lines, and regardless of the lines beginning with * which are comments or notes for help:

Line 1: integer
integer :   max number of different marks, now is 10

Line 2: text integer real real integer real real   (OK)
text:  typepoint  is the point for general use
integer: 1=constructed point, 2=minicircle - print
real: radius of minicircle in mm - print
real: offset in mm - print
integer: 1=unidimensional, 2=minicircle - laser
real: radius of minicircle in mm - laser
real: offset in mm - laser

Line 3: text integer real real integer real real   (still not used, set defaults)
text:  typepoint2
integer: 1=unidimensional, 2=minicircle - print
real: radius of minicircle in mm - print
real: offset in mm - print
integer: 1=unidimensional, 2=minicircle - laser
real: radius of minicircle in mm - laser
real: offset in mm - laser

Line 4: text integer real real integer real real   (still not used, set defaults)
text:  typepoint3
integer: 1=unidimensional, 2=minicircle - print
real: radius of minicircle in mm - print
real: offset in mm - print
integer: 1=unidimensional, 2=minicircle - laser
real: radius of minicircle in mm - laser
real: offset in mm - laser

Line 5: text integer real real integer real real  (OK)
text:  typevent
integer: 1=two green points, 2=segment, 3=double segment - print
real: points separation or segment in mm - print
real: offset in mm - print
integer: 1=two green points, 2=segment, 3=double segment - laser
real: points separation or segment in mm - laser
real: offset in mm - laser

Line 6: text integer real real integer real real  (OK)
text:  typetab
integer: 1=tree orange points, 2=tree orange full control, 3=triangle - print
real: points separation or segment in mm - print
real: offset in mm - print
integer: 1=tree orange points, 2=tree orange full control, 3=triangle - laser
real: points separation or triangle height in mm - laser
real: offset in mm - laser

Line 7: text integer real real integer real real (still not used, set defaults)
text:  typejonc
integer: 1=single point, 2=segment, 3=double segment - print
real: points separation or segment in mm - print
real: offset in mm - print
integer: 1=single point, 2=segment, 3=double segment - laser
real: points separation or segment in mm - laser
real: offset in mm - laser

Line 8: text integer real real integer real real  (still not used, set defaults)
text:  typeref
integer: 1,2,3 - print
real: dimesion in mm - print
real: offset in mm - print
integer: 1,2,3 - laser
real: dimension in mm - laser
real: offset in mm - laser

Line 9: text integer real real integer real real  (OK)
text:  type8 - romano numbering in panels generated using section 29
integer: 1 not used
real: 0.2 spanning from 0.0 to 1.0 means the position of the roman number (0.0 totally to the left and 1.0 totally to the right, normal values 0.2 or 0.5 - print and laser
real: 4.0 means the vertical offset in mm with respect to the baseline. May be positive or negative number - print and laser
integer: 1 not used
real: 0.0 not used
real: 4.4 means the offset in mm between dots of the roman numeral (global size of the roman numerals) - print and laser

Line 10: text integer real real integer real real  (OK)
text:  type9 -  general numbers size, and roman marks size in ribs,
integer: 1 not used
real: 0.0 not used
real: 7.0 decimal integer numbers size in cm, in leading edge, ribs, trailing edge panels
integer: 1 not used
real: 3.3 means the offset in mm between dots of the roman numeral (global size of the roman numerals) in rod pockets. If set to 0.0 then roman is not drawn
real: 4.5 means the offset in mm between dots of the roman numeral (global size of the roman numerals) in ribs - print and laser

Line 11: text integer real real integer real real  (OK)
text:  type10 -  general numbers size in VH-ribs, and roman marks size in VH-ribs,
integer: 1 not used
real: 0.0 not used
real: 6.0 decimal integer numbers size in cm, in VH-ribs
integer: 1 not used
real: 0.0 not used
real: 4.5 means the offset in mm between dots of the roman numeral (global size of the roman numerals in VH-ribs) - laser

Section is fully functional. Now it is possible to define type 1 and type 2 rods, which are the most used. Type "1" is  rod on the nose with small deflections at both ends, which are completely controllable in position, transition, and depth of deflection, with 8 parameters. Type "2" is straight or arched rod defined to any position within the profile, which can be at any position within the profile, defined by coordinates. The structure of the section is a bit complex, but it has its own logic. The program calculates the rods and shapes of the pockets, which are also fully controllable in widths, with 4 parameters. It is possible to define different rods for each cell, individually or by groups. If you don't need rods, leave the value to "0". In this section we will use the following basic concepts: scheme, bloc (of data), type (of rod), group (of ribs).

The first number in the section is an integer, which we called the "scheme".

The scheme "0" means, not defining any rod. And here ends the section. Easy!

Line 1: integer
if integer = 0 rods are not considered

Example 1: Scheme "0" means do not use rods
*******************************************************
*       21. JONCS DEFINITION (NYLON RODS)
*******************************************************
0

The scheme "1" means use rods type "1" in the nose. At the bottom line write the number of groups. Then write each group consecutively using four lines. This is the detailed structure of the scheme 1:

Note: Remember usual color index numbers for CAD systems:
1= red, 2=yellow, 3=green, 4=cyan, 5=blue, 6=magenta 7=white 8=dark grey 9= grey,... up to 255 depending on your color palette. It is preferable not to use colors with more than two digits.

SECTION 25: GENERAL 3D DXF OPTIONS


Line 1: integer
if integer = 0 DXF options set by default
if integer = 1 add some others parameters for the 3D DXF

Only if first integer is 1 then add:

Line 2: text1  integer  text2
tex1: A_lines_color (do not change this text)
integer: color number index for "A" lines
text2: color name (optional text not used)

Line 3: text1  integer  text2
tex1: B_lines_color (do not change this text)
integer: color number index for "B" lines
text2: color name (optional text not used)

Line 4: text1  integer  text2
tex1: C_lines_color (do not change this text)
integer: color number index for "C" lines
text2: color name (optional text not used)

Line 5: text1  integer  text2
tex1: D_lines_color (do not change this text)
integer: color number index for "D" lines
text2: color name (optional text not used)

Line 6: text1  integer  text2
tex1: E_lines_color (do not change this text)
integer: color number index for "E" lines
text2: color name (optional text not used)

Line 7: text1  integer  text2
tex1: F_lines_color (do not change this text)
integer: color number index for "F" brake lines
text2: color name (optional text not used)

Line 8: text1 integer integer text2
tex1: Extrados (do not change this text)
integer: if set to "0" unifiilar extrados is not drawn, if set to "1" is drawn
integer: color index for the extrados
text 2: optional text with the color name

Line 9: text1 integer integer text2
tex1: Vents (do not change this text)
integer: if set to "0" unifiilar vents is not drawn, if set to "1" is drawn
integer: color index for the vents
text 2: optional text with the color name

Line 10: text1 integer integer text2
tex1: Intrados (do not change this text)
integer: if set to "0" unifiilar intrados is not drawn, if set to "1" is drawn
integer: color index for the intrados
text 2: optional text with the color name

Example:
*******************************************************
*       25. GENERAL 3D DXF OPTIONS
*******************************************************
1
A_lines_color    1     red
B_lines_color    8     grey
C_lines_color    8     grey
D_lines_color    8     grey
E_lines_color    8     grey
F_lines_color    30    orange
Extrados    1    5     blue
Vents       0    1     red
Intrados    1    3     green

SECTION 26. GLUE VENTS

This section allows us to define different types of air inlets (vents), and  automatically "glue" into the panel of extrados, intrados, or to separate them. The vents include sewing edges. The skin tension in the vent is linear and automatically corresponds to that defined at the points corresponding in extrados and intrados.

The vent definition is very easy and intuitive. A row is defined for each rib. The first number is the rib number, the next is the vent type, and then zero, two, or three parameters, depending on the type.

Available vent types (version lep-3.17) 0,1,-1,-2,-3,4,-4,5,-5,6,-6:

0 means do not glue anywhere (open air inlet).
1 means glue the vent to the extrados (normally used in paragliders single skin type)
-1 means glue the vent to the intrados (usually means, closed cell)
-2 means diagonal vent 100% open ant left, glued to intrados
-3 means diagonal vent 100% open alt right, glued to intrados
-4 50 30 mean general diagonal vent 50% closed at left and 30% closed at right, glued to intrados
 4 0 80 mean general diagonal vent 0% open at left and 80% open at right, glued to extrados
5 50 100 10 mean arched vent, 50% open at left, 100% open at right, and 10% arc depth, glued to intrados
-5 50 40 15 mean arched vent, 50% closed at left, 40% closed at right, and 15% arc depth, glued to intrados
6 80 80 means elliptical inlet, width of 80% in X direction and 80% in Y direction, glued to extrados
-6 50 85 means elliptical inlet, width of 50% in X direction and 85% in Y direction, glued to intrados

Section 26 structure:

Line 1: integer
if integer = 0 then end the section and use old vents style (not recommended)
if integer = 1 add some others parameters for precise vents control

Only if first integer is 1 then add N lines, one for each airfoil number i:

Line i: integer1 integer2 real1 real2 real3
integer1: airfoil number (cell between airfoil i and airfoil i-1)
integer2: vent parameter (available parameters 0,1, -1,-2,-3,4,-4,5,-5,6,-6 as explained above)
real1: parameter 1 (0 to 100). Start point at left (vents 4,-4,5,-5), or horizontal axis in 6,-6
real2: parameter 2 (0 to 100). Start point at right (vents 4,-4,5,-5), or vertical axis in 6,-6
real3: parameter 3 (0 to 100). Arch depth in vents type 5 or -5

Examples 1 (use old style, not recommended):

*******************************************************
*       26. GLUE VENTS
*******************************************************
0

Examples 2 (full vent control):

*******************************************************
*       26. GLUE VENTS
*******************************************************
1  
1    0
2    0
3    1
4   -2
5   -3
...
20  -2
21  -1
22  -1
23  -1

Examples 3 (advanced vents):

*******************************************************
*       26. GLUE VENTS
*******************************************************
1  
1    0
2    0
3    1
4   -4 100. 0.   ---> general diagonal vent from 100% to 0%
5   -4 10. 50.   ---> general diagonal vent from 10% to 50%
...
19  -5 0. 0. 15  ---> arc vent 15% depth
20  -6 80 80     ---> elliptical inlet
21  -1
22  -1
23  -1


Figure 30. Glue vents


Figure 31: Vents types 0,1,-1,-2,-3


Figure 31b: Vents types -4,4 (general diagonal) -5,5 (general arc) -6,6 (elliptical inlet), available in lep-3.17 and later. Note that type 4 also includes cases 0,1,2,3, and type -4 cases 0, -1, -2, -3. Finally type 5 includes case 4, and -5 includes case -4.


SECTION 27 SPECIAL WINGTIPS

It is used for defining wingtips with special shapes:

Figure 32. Special wingtip

Line 1: integer
if integer = 0 do not add wingtip modifications(set by default)
if integer = 1 add some wingtip modifications

Only if first integer is 1 then add:

Line 2: text  real
text: AngleLE (do not change this text)
real: angle in degrees between the horizontal and the leading edge in the last cell

Line 3: text  real
text: AngleTE (do not change this text)
real: angle in degrees between the horizontal and the trailing edge in the last cell

Example 1:
*******************************************************
*       27. SPECIAL WING TIP
*******************************************************
1
AngleLE 45
AngleTE -7.78

"1" refers to define "type 1" wing tip modifications. It is planned to define several modifications. Type 1 is the simplest.
"AngleLE" is a name not computed. It serves to remember that next we have to write the new angle in degrees between the horizontal and the leading edge in the last cell. It is usual to force the angle of the last cell, and this section allows it to be done without modifying the geometry matrix. Set 45º for example. "AngleTE" is a name not computed for the trailing edge. Set the angle as desired, -7.78º for example.

Example 2:
*******************************************************
*       27. SPECIAL WING TIP
*******************************************************
0

SECTION 28 PARAMETERS FOR CALAGE VARIATION

Study the variations in the riser lengths and calage when applying speed system or trim system. It is interesting to experiment with new calages in prototypes or to define the speed or trim systems.

Figure 33. Principles of the study of the calage variations.

We study the variations in the riser lengths when applying accelerator (speed system) pivoting in the last riser (most common case), which remains with constant length. For practical purposes we define a negative alpha  angle of pitch increased in N1 spaces gradually, and then we compute  the variations in the line  lengths and calage. We do the same study, assuming a trim system that increases the picth angle in N2 spaces gradually. In this case, the most usual is to consider the constant length A riser and the other variables in length.

The program analyzes a total of 4 cases, depending on the pivot point and if it is reduction or increase in angle:

Figure 34. Cases a,b,c,d reported in file lep-out.txt

In output file SECTION 7: lep-out.txt we see the tables that relate in detail the variations of angle, with the calage variations, and increments or decrements of length in each riser. It is interesting to experiment with new calages in prototypes or to define the speed or trim systems. Four cases:
a) Speed system pivot in last riser
b) Speed system pivot in first riser
c) Trimer system pivot in first riser
d) Trimer system pivot in last riser

 Example lep-out.txt:
a) Speed system pivot in last riser:
 -------------------------------------------
 i   alpha       A       B       C  Calage
 1     .00     .00     .00     .00   25.00
 2   -1.00   -2.18   -1.29     .00   21.19
 3   -2.00   -4.35   -2.59     .00   17.40
 4   -3.00   -6.52   -3.88     .00   13.66
Column 2 > angle alpha in degrees
Column 3 > Decrease of length A riser (amount of accelerator) in cm
Column 4 > Decrease of length B riser in cm
Column 5 > Decrease of length C riser in cm = 0 (pivot in C riser)
Column 6 > New calage %

Write data in in SECTION 28 with one or four lines:

Line 1: integer
if integer = 0 do nothing
if integer = 1 do calage study "type 1"

Only if first integer is 1 then add:

Line 2: integer
integer: number of risers to be considered (2,3,4,5 or 6)

Line 3: real1 real2 real3 real4 real5 real6
real1: % of central chord for riser A (is not necessary to match anchor position)
...
real6: % of central chord for riser E (is not necessary to match anchor position)

Line 4: real1 integer1 real2 integer2
real1: max angle (negative) in degrees set by the speed system
integer1: number of steps in angle for study purpose
real2: max angle (positive) in degrees set by the trim system
integer2: number of steps in angle for study purpose

Example:
*******************************************************
*       28. PARAMETERS FOR CALAGE VARIATION
*******************************************************
1
3
10. 30.35  60  0  0  0
-4 4 5 10
*******************************************************

Explanation:
Set to calage type "1" (first line), only type "1" available
"3" risers to be considered
A=10.%  B=30.35%  C=60%  D=  E=  F=   (set % to be considered)
Speed angle set to -4º and compute in 4 steps
Trim angle set to 5º and compute in 10 steps


Figure 35. New graphic in plan 2-1 (.dxf output)


SECTION 29 3D SHAPING

The model of 3-Shaping proposed by the Laboratori, consists in making one or two transverse cuts in the upper surface, near the leading edge, and another optional cut on the bottom surface. We will call this model as "type 1". The edges of the transverse cuts will be modified from the straight line into an arc of a circle. In this way, we can "add fabric" lengthwise and we can control the ovalization and the tension in this direction. Ovalization in transverse direction is achieved via the module of skin tension (SECTIONS 5 or 31). In summary, we can control the amount of tissue and tension in transverse and in longitudinal direction near the nose, where the curvatures are greatest.

To set the parameters of the 3D-shaping in the model "type 1" is necessary to study the profile in detail, viewing and counting the individual points that form it, Laboratori style! :-) You need to view your profile in CAD (or in the .txt file), identify and count points. Remember that the points in a profile is counted starting in the trailing edge (point 1), continuing by the upper surface, nose, vents, lower surface, and ending again in the trailing edge. Exactly as described previously. We could define another model "type 2" where the position of the cut points are defined in % of the length of the panel, but in this model 1, is considered to specify exactly the points considered.

For each cut, it is necessary to define a "zone of influence". In the zones of influence is measured the length of a section of the profile and is compared with the corresponding length in the ovalized profile. This question is fundamental to understand the 3D-shaping type 1. It is necessary to view the figure below:


Figure 36. Cuts and zones of influence. J1,j2,j3,j4,j5,j6,j7 indicate numeric values of the selected points in the profile, starting to count from the trailing edge. J4 and j5 are the vent points.

For the purposes of notation, we will call the different parts in which we divide the profile as:
zone 1 (between j1 and j2), extrados part 1
zone 2 (between j2 and j3), extrados part 2
zone 3 (between j3 and j4), extrados part 3 or nose
zone 4 (between j4 and j5), or vents
zone 5 (between j5 and j6), intrados part 1
zone 6 (between j6 and j7), intrados part 2

In each zone 1,2,3,4,5,6 the program computes the length ot the arch of airfoil (d1) and the arch of the ovalized airfoil (d2). The differences of longitude (d2-d1) are calculated automatically in each zone, and then applied consistently to each cut with a value (f) obtained using the values (d2-d1) of the adjacent zones. Is provided a setting parameter around 1.0, which serves the designer to regulate the depth of the 3D-shaping in each cut (positive or negative), in relation to the automatic calculation. Thus, using the coefficient of 1.0, the depth of 3D is according to the theory exposed. Using a coefficient of 0.0 does not apply the 3D effect, and using values higher or lower than 1.0 increases or decreases the effect. The control of the depth of 3D-shaping is continuous and individual for each cut. A more detailed description, and the formulas used in the calculation are described in this technical note about 3D-shaping. For each rib, a full report of the values d1, d2, d2-d1, computed in each zone, and the final values f aplied in each cut are printed in tabular form in section 9 of the file lep-out.txt. Also, for verification purposes, a new section 10 is written to the lep-out.txt file with the counting of the points of each profile, to verify that they are all the same for all profiles, and that they are compatible with the defined cuts.

It should be noted, that the parameters applied in this section, will be usually "invariant values" applied to the majority of the designs. We just have to think about all this, a single time for each type of profile. And the Laboratory will provide soon the recommended values in next designs. Of course, finding the good parameters is a real art. The program LEparagliding now provides the tools to make numerical and graphical experiments (lep-out.txt section 9 and leparagliding.dxf plan in box 1-8).

Negative 3D-shaping values are available since version 3.11

Explanation of the parameters in SECTION 29:

Line 1: integer
if integer = 0 then no not use 3D-shaping, and finish writing the section.
if integer = 1 then use 3D-shaping, and continue writing:

Line 2: integer
integer = type of 3D-shaping theory used, now we use only model "type 1" using transverse cuts, set parameter to 1.

Line 3: character  integer
character = groups
integer1 = number of groups used

Line 4: character  integer1  integer2  integer3
character = group
integer1 = number of the group
integer2 = initial rib in group
integer3 = final rib in group

Line 5: character  integer1  integer2
character = upper , word meaning upper surface (extrados)
integer1 = number of cuts in upper surface (possible values 1 or 2).
integer2 = subtype of cuts, set to 1, only value accepted

Line 6: integer1  integer2  real
integer1 = initial point in the first zone of influence (j1)
integer2 = point where the first cut is set (j2)
real = "depth" of 3D-shaping in the cut, possible values -1.0,-0.4,0.0, 0.1,....,1.0,1.2,... (multiplier coefficient around +-1.0)

Line 7: integer1  integer2  real   (only if we use two extrados cuts)
integer1 = initial point in the second zone of influence (j2)
integer2 = point where the second cut is set (j3)
real = "depth" of 3D-shaping in the cut, possible values -1.0,-0.4,0.0, 0.1,....,1.0,1.2,... (multiplier coefficient around +-1.0)

Line 8: character  integer1  integer2
character = lower , word meaning lower surface (intrados)
integer1 = number of cuts in lower surface (possible values 0 or 1).
integer2 = subtype of cuts, set to 1, only value accepted

If the number of cuts in intrados is 0, stop writing, else

Line 9: integer1  integer2  real   (only if we use two extrados cuts)
integer1 = point where the intrados cut is set (j6)
integer2 = final point in the intrados zone of influence (j7)
real = "depth" of 3D-shaping in the cut, possible values -1.0,-0.4,0.0, 0.1,....,1.0,1.2,... (multiplier coefficient around +-1.0)

(...Repeat lines 5,6,7,8,9 for next groups...)

Line 10: character
character =  "* print parameters:" (comment line, it is mandatory to write something)

Line 11: character  integer1  integer2 integer3  integer4
character = Inter3D, word to indicate representation of the intermediate airfoils in 3D lep-3d.dxf
integer1 = 0 indicates do not draw, and 1 draw
integer2 = index of first airfoil to draw
integer3 = index of last airfoil to draw
integer4 = 0 it indicates to draw with symmetry, 1 only one side

Line 12: character  integer1  integer2 integer3  integer4
character = Ovali3D, word to indicate representation of the intermediate ovalized airfoils in 3D lep-3d.dxf
integer1 = 0 indicates do not draw, and 1 draw
integer2 = index of first airfoil to draw
integer3 = index of last airfoil to draw
integer4 = 0 it indicates to draw with symmetry, 1 only one side

Line 13: character  integer1  integer2 integer3  integer4
character = tesse3D, word to indicate representation of panel tessellation in 3D lep-3d.dxf
integer1 = 0 indicates do not draw, and 1 draw
integer2 = index of first panel to draw
integer3 = index of last panel to draw
integer4 = 0 it indicates to draw with symmetry, 1 only one side

Line 14: character  integer1  integer2 integer3  integer4
character = exteDXF, word to indicate representation of panels tessellation in 3D in a new external DXF file (possible use in CFD analysis)
integer1 = 0 indicates do not draw, and 1 draw
integer2 = index of first panel to draw
integer3 = index of last panel to draw
integer4 = 0 it indicates to draw with symmetry, 1 only one side

Line 15: character  integer1  integer2 integer3  integer4
character = exteSTL, word to indicate representation of panels tessellation in 3D in a new external STL file (used with programs of 3D modelling as OpenSCAD or FreeCAD)
integer1 = 0 indicates do not draw, and 1 draw
integer2 = index of first panel to draw
integer3 = index of last panel to draw
integer4 = 0 it indicates to draw with symmetry, 1 only one side

If section 29 is not "0" then lines 12, 13, 14, 15 are mandatory to write. Since lep-3.19 the actions are fully functional. These parameters will generate independent dxf files with the ovalized surfaces, and even a .stl model to view with FreeCAD or OpenSCAD, or even analyze with CFD programs.

All this may seem complicated, but it is much easier to understand section structure watching a few examples:

Example 1: Do not use 3D-shaping. Set one line with "0" parameter and stop writting. It is the simplest solution to avoid the complicated 3D-shaping module! :)

*******************************************************
*       29. 3D SHAPING
*******************************************************
0

Example 2: Active 3D-shaping module but without any cut. The utility of defining this, is that the representation of plan 1-8 is activated automatically, with the drawing of the intermediate and ovalized airfoils in 2D. You can also activate the 3D representations in 3D, changing the settings "0" to "1" in the "Print parameters" subsection. In general, preferable to use example 2, that use the example 1 (the two are invariant sections).

************************************************************
*       29. 3D SHAPING
*******************************************************
1
1
groups  1
group   1    1    1
upper   0    1
lower   0    1
* Print parameters
Inter3D 0    1    1    0
Ovali3D 0    1    1    0
tesse3D 0    1    1    0
exteDXF 0    1    1    0
exteSTL 0    1    1    0

Example 3. Easy case, only one group and one cut in extrados.
First group from rib 1 to 14 using one cuts type 1 in upper surface and zero in lower surface.
Zone of influence of first cut started in point 30 and cut located in point 40, depth of the effect 0.8.
Zero cuts in lower surface, type 1.
Prints 3D intermediate (Inter3D) and ovalized (Ovali3D) airfoils at the left of ribs 1 to 14

*******************************************************
*       29. 3D SHAPING
*******************************************************
1
1
groups   1
group    1    1   14
upper    1    1
1       30   40   0.8
lower    0    1
* Print parameters
Inter3D 1    1    14    0
Ovali3D 1    1    14    0
tesse3D 0    1    1     0
exteDXF 0    1    1     0
exteSTL 0    1    1     0

Example 4: General case, using two groups.

First group from rib 1 to 10 using two cuts in upper surface and one in lower surface.
Zone of influence of first cut started in point 25 and cut located in point 33, depth of the effect 0.8.
Zone of influence of the second cut in point 33 and cut located in point 44, depth of the effect -0.3.
Cut in lower surface in point 79 and zone of influence up to point 84, depth of effect 1.0.

Second group from rib 11 to 14 using two cuts in upper surface and one in lower surface.
Zone of influence of first cut started in point 25 and cut located in point 33, depth of the effect 0.9.
Zone of influence of the second cut in point 33 and cut located in point 44, depth of the effect 0.9.
Cut in lower surface in point 79 and zone of influence up to point 83, depth of effect 1.0.

*******************************************************
*       29. 3D SHAPING
*******************************************************
1
1
groups   2
group    1    1   10
upper    2    1
1       25   33   0.8
2       33   44  -0.3
lower    1    1
1       79   84   1.0
group    2   11   14
upper    2    1
1       25   33   0.9
2       33   44   0.9
lower    1    1
1       79   83   1.0
* Print parameters
Inter3D 1    1    14    0
Ovali3D 1    1    14    0
tesse3D 0    1    1     0
exteDXF 0    1    1     0
exteSTL 0    1    1     0

Example 5: Enabling the external DXF and STL files.

************************************************************
*       29. 3D SHAPING
*******************************************************
1
1
groups  1
group   1    1    1
upper   0    1
lower   0    1
* Print parameters
Inter3D 0    1    1    0
Ovali3D 0    1    1    0
tesse3D 1    1    15    1   > Enable 3D tessellation in lep-3d.dxf from panel 1 to 15 and do symmetrical
exteDXF 1    1    15    0   > Enable 3D tessellation in independent file lep-3d-surfaces.dxf from panel 1 to 15 and do one side
exteSTL 1    1    15    1   > Enable 3D tessellation in independent files lep-3d-surfaces.scad and lep-3d-surfaces.stl from panel 1 to 15 and do symmetrical

lep-3d.dxf with tessellation active. line colors, defined according to section 25	lep-3d-surfaces.dxf  external dxf file showing only one cell
One panel in OpenSCAD	One panel in OpenSCAD (rendered)
Full wing model in OpenSCAD, file lep-3d-surfaces.scad automatically generated	lep-3d-surfaces.scad
lep-3d-surfaces.scad	lep-3d-surfaces.scad
Automatically generated file lep-3d-surfaces.stl View and renders in OpenSCAD STL file can probably be used in CFD analysis	Automatically generated file lep-3d-surfaces.stl View and renders in FreeCAD

Some limitations of 3D surfaces:

- The scad model allows us to view the entire wing without problems (key [F5]), but does not allow rendering (key [F6])I'm trying to find out why.
- The 3D surfaces accurately represent the law of skin tensions, but currently do not take into account 3D shaping. Perhaps later, I try to represent this effect
- The number of points in the tessellation is equal to the number of points in the profile around its outline, and a fixed number of segments in the transverse direction. The parameter nsegments=8 has been defined internally. If you need a finer mesh, change this setting (compile the program or ask me).

General notes:

The location of the cut points depends mainly on the study of the shape of the profile. It is interesting to concentrate the cuts where the difference in lengths between segments located in the intermediate profile and the ovalized (balloned) profile are larger. As a first approximation, can be studied to place the cuts in the 5.5% and 13.5% of the profile chord, counting from the leading edge. It is also important to choose correctly the coefficient of depth. Theoretically 1.0 is the best, but to smooth out the surfaces, you can choose a smaller coefficient.

As Piet suggests from the Netherlands, the 3D module can also be used as a simple alternative to separate colored panels in the noses area, or panels with more durable fabric. Remember that the 3D effect is adjustable in depth, and you can even use the parameter amplification 0.0 so that the cut between the parts of the panels is completely straight line. The subroutines developed in this section will be adapted to complete the separation in parts of colors.

The programming of this 3D-shaping module has been made possible thanks to the support of Scott Roberts from USA (Fluid Wings https://www.fluidwings.com/ ).

SECTION 30: AIRFOIL THICKNESS MODIFICATION

Coefficients of amplification or reduction of the thickness of the cells. Normally define as "1.0", or "0.0" in the wingtip.

Line 1: integer
if integer = 0 then no airfoil amplification set
if integer = 1 then add:

Lines 1,2,3,...,maxrib: integer   real
Integer: set rib number (1,2,3...) in all ribs
real: set amplification coefficient, for example 1.0 as default

Example:
*******************************************************
*       30. AIRFOIL THICKNESS MODIFICATION
*******************************************************
1
1    1.2
2    1.1
3    1.0
4    1.0
5    1.0
6    1.0
7    1.0
8    1.0
9    1.0
(...)
23   0.0

SECTION 31: NEW SKIN TENSION

The correct definition of the skin tension is essential for the internal solidity and the flight quality of the apparatus. For this reason, it is recommended that the designer have total control over the skin tension, with a very precise form (law of increments of width), and allowing changes in different panels along the span. This is what allows the new module.

The module new skin tension, functional from version 3.00, defines the additional widths of panels, to achieve the desired ovalitzation. The values applied to the extrados and intrados, for compatibility are the same as those explained in SECTION 5, but there is a greater control. The number of points to define the widths is not limited to 6, now can be up to 100 points (!) (to choose freely). And it is possible to choose different widths for each one of the ribs, if it is considered necessary, (defining different "groups" of widths). Of course, the number of groups can be equal to the number of ribs, and thereby define the widths of each panel individually (for example, different tension in the panels of the center panels and in the wingtip).

The basic idea is to calculate increments of width to the left and to the right of each rib. Thus, a panel can have a 2% increase maximum in the left border and a 3% maximum to the right border. Negative values of increase are also acceptable, although I recommend not to use to simplify.

It is very recommended to use always the same number of points among different groups, because the current programming can generate undesiderd distortions (to be corrected soon).

The system allows to define in detail the tension in the extrados and intrados surfaces, but in the air inlets (vents)? The program automatically adds a linear transition in the vents area between extrados and intrados.

The "mysterious" two correction parameters of the last two lines of section 5 continue to have application. Normally no need to modify ever. I recommend use always:
 1000   1.0

There are different ways of defining the skin tension. In the current version it is only active the version of "type 1", which consists of a linear interpolation and a width of reference for applying the law of increments of width, equal to the average width of each panel. Given the large amount of points available to interpolate (100) is not strictly necessary, a version with splines "type 2", to propose later. Usually with 10 or 15 points, linear interpolation is sufficient (old version uses only 6). Another proposal to consider is a version of linear interpolation "type 3" where the law of increments of width is not in reference to the mean width of the panel, but the width existing at each point between two adjacent profiles adjacent (possibly this is the solution that is most perfect).

To clarify and better explain all these fundamental issues, soon I'll be posting an article with diagrams.

Explanation of the parameters in section 31:

Line 1: integer
if integer = 0 then no not use new skin tension module, and finish writting the section.
if integer = 1 then use new skin tension module, and continue writting:

Line 2: integer
integer = number of skin tension grups (max= number of ribs)

Line 3: character
character = comment line explaining the group "i" from rib n1 to rib n2, using X points, and type "1".
(for now, only type "1" is possible, and means it uses linear interpolation between points. Add more points to smooth out, if necessary.)

Line 4: integer1 integer2 integer3 integer4 integer5
integer1 = group number
integer2 = initial rib
integer3 = final rib
integer4 =  points for interpolation
integer5 = 1 , type linear of interpolation

Lines 5 to 5-1+ npoints of interpolation: integer real1 real2 real3 real4
integer = point of interpolation in consucutive order
real1 = Distance in % of length of the extrados panel starting in the leading edge
real2 = Additional width in % of the extrados panel
real3 = Distance in % of length of the intrados panel starting in the trailing edge
real4 = Additional width in % of the intrados panel

(Same geometric definition as in SECTION 5.)

In the following lines. Continue describing groups starting with the line of comments.

Examples:

Example 1 (do not use new skin tension module):

*******************************************************
*       31. NEW SKIN TENSION MODULE
*******************************************************
0

Example 2:
*******************************************************
*       31. NEW SKIN TENSION MODULE
*******************************************************
1
3
* Skin tension group number "1" from rib 1 to 10, 7 points, type "1"
1    1    10    7    1
1    0.         0.5     0.         0.
2    7.5        1.3     10.        1.33
3    15.        2.5     20.        2.5
4    80.        2.5     80.        2.5
5    90.        1.33    90.        1.33
6    95.        0.65    95.        0.9
7    100.       0.0    100.        0.5
* Skin tension group number "2" from rib 11 to 19, 7 points, type "1"
1    11    19    7    1
1    0.        0.5       0.        0.
2    7.5        1.3     10.        1.33
3    15.        2.5     20.        2.5
4    80.        2.5     80.        2.5
5    90.        1.33    90.        1.33
6    95.        0.65    95.        0.9
7    100.       0.0    100.        0.5
* Skin tension group number "3" from rib 20 to 23, 7 points, type "1"
1    20    23    7    1
1    0.         0.5      0.         0.
2    7.5        1.3     10.         1.33
3    15.        2.5     20.         2.5
4    80.        2.5     80.         2.5
5    90.        1.33    90.         1.33
6    95.        0.65    95.         0.9
7    100.      -0.5    100.         0.5
********************************************************

SECTION 32: PARAMETERS FOR PARTS SEPARATION

The program separates the different pieces (panels, ribs, ...) drawn in 2D automatically, trying to not overlap with each other or put outside the drawing box. However, sometimes the separation between the pieces is not as we would like. Therefore, we have added some parameters to modify the automatic separation criteria. These are coefficients, around 1.0 that reduce or increase the separations in horizontal (x) or vertical (y) directions. If in doubt, do not need to change any of the parameters in this section, leave the default values to 1.0, or put a single parameter 0 at the beginning, which is equivalent to maintaining the default default values. And so it will be an invariant section for all models.

Example1:

*******************************************************
*       32. PARAMETERS FOR PARTS SEPARATION
*******************************************************
0

Example2:

*******************************************************
*       32. PARAMETERS FOR PARTS SEPARATION
*******************************************************
1
panel_x        1.1
panel_x_min    1.0
panel_y        0.9
rib_x          1.0
rib_y          1.15
parameter6     1.0
parameter7     1.0
parameter8     1.0
parameter9     1.0
parameter10    1.0

Explanation of the parameters in section 31:

Line 1: integer
if integer = 0 then use default internal parameters, and finish writting the section.
if integer = 1 then use control parameters, and continue writting ten lines:

Line 2: character real
character = parameter 1 name
real= multiplication factor for x-direction panels separation

Line 3: character real
character = parameter 2 name
real= multiplication factor for x-direction panels minimum separation

Line 4: character real
character = parameter 3 name
real= multiplication factor for y-direction panels separation

Line 5: character real
character = parameter 4 name
real= multiplication factor for x-direction ribs separation

Line 6: character real
character = parameter 5 name
real= multiplication factor for y-direction ribs separation

Line 7: character real
character = parameter 5 name
real= multiplication factor for adjust separation in y-direction the horizontals straps type 1 or 11.

Lines 8,9,10,11: character real
character = parameter name
real= 1.0 (parameter still not used)

To better understand, initially set all parameters to 1.0 and then make changes to see the results.


Figure 37. Section 32 example. The panels above have been drawn with a compact configuration (panel_x = 1.0, panel_y = 0.3). The panels below have been drawn with a more separate configuration (panel_x = 1.2, panel_y = 1.2).

SECTION 33: DETAILED RISERS

Type a single parameter "0" to bypass this section and use pre-set values :)

Example:

*******************************************************
* 33. DETAILED RISERS
*******************************************************
0

Type 1 and additional parameters to design a paraglider with risers of different lengths A, B, C, D, E (not usual, but sometimes it may be necessary). Works.
Type 2,3 or 4 to project the risers of a vario seat system of two, three, four points (types 2,3,4 still not available).

Example:

*******************************************************
* 33. DETAILED RISERS
*******************************************************
1
1
A 45.0 cm
B 50.0 cm
C 60.0 cm

Explanation of the parameters in section 33:

Line 1: integer
if integer = 0 then use default internal parameters, and finish writting the section.
if integer = 1 then use control parameters, and continue writting ten lines:

Line 2: integer
 integer= risers type (1= risers of defined length, 2= vario seat two points, 3=vario seat three points, 4=vario seat four points)

And then write N lines, being N=number of risers according definition in section

Lines 3 to 3+N-1: character1 real character2
character = write A,B,C,D,E... according riser definition in SECTION 8 (nrisers=plans number)
real= riser length in cm
character = cm

SECTION 34: LINES CHARACTERISTICS TABLE

Type a single parameter "0" to bypass this section and use predefined typical values. Definition table of the properties of N different types of lines used in our paraglider. Up to 50 different types of lines. Define your own lines types according to manufacturers' tables.

Example:

*******************************************************
* 34. LINES CHARACTERISTICS TABLE
*******************************************************
1
6
1 r 25. 2. Riser 1000 daN polyester 20.0  g s 12. cm 7
2 c 1.90 Line275  275 daN s_dyneem 2.26 g s 12. cm
3 c 1.40 Line160  160 daN s_dyneem 1.34 g s 10. cm 3
4 c 1.15 Line120  120 daN s_dyneem 1.00 g s 10. cm 5
5 c 0.80 Line100U 100 daN u_dyneem 0.43 g p 8.  cm 2
6 c 2.00 Line200B 200 daN s_dynemm 3.10 g s 12. cm 6

Each type is described in a line with 12 positions:
1 --> Line type
2 --> r or c (r=rectangular axb or c=circular section)
3 --> line diameter (mm) or a dimensions (mm)
3.5 --> nothing or b dimension (mm), used only in "r" types
4 --> line label "Riser", "PPSL275", "DC60",... use names without spaces up to 15 characters
5 --> minimum breaking strenght (daN)
6 --> daN
7 --> material type "dyneema", "aramid", "polyester"... use names without spaces up to 15 characters
8 --> weight per line meter (g)
9 --> g
10 --> s or p (s=stitched or p=spliced loop)
11 --> total loop length (cm
12 --> cm
13 → set line CAD color, used only if code 1341 is active in section 37 (idea by Eric Fontaine)


SECTION 35: SOLVE EQUILIBRIUM EQUATIONS

Read full report here about improvements added since version 3.20V (pdf)

Type a single parameter "0" to bypass this complicated section! :)

*******************************************************
* 35. SOLVE EQUILIBRIUM EQUATIONS
*******************************************************
0

Section 35 sets the initial basic parameters used to solve the longitudinal equilibrium of the paraglider. This section is informative and is used by the designer, to study the values of the forces involved in the balance of the wing, the flight speed, the angles, and the glide coefficient.

To find realistic values, it is necessary to do the study simultaneously with the XFLR5 program or CFD programs, and perform several iterations until satisfactory values are obtained. Currently, it is not yet possible to fully automate this calculation. The designer must apply his criteria according to the type of wing under study.

We have discussed this section extensively with Francois de Villiers during the last few weeks, using different approaches to the final solution.

*******************************************************
* 35. SOLVE EQUILIBRIUM EQUATIONS
*******************************************************
1
g 9.807 m/s2 gravity of Eart
ro 1.225 kg/m3 air mass density
mu 18.46 muPa·s air dynamic viscosity (microPascals)
V 12.7 m/s estimated flow speed
Alpha 9.45 deg estimated wing angle of attact at trim speed
Cl 0.55619 wing lift coefficient
cle 1.0 lift correction coefficient
Cd 0.03560 wing drag coefficient
cde 1.35 drag correction coefficient
Cm 0.0 wing moment coefficient
Spilot 0.438 m2 pilot+harness frontal surface
Cdpilot 0.6 pilot+harness drag coefficient
Mw 5.0 kg wing mass
Mp 65.9 kg pilot mass included harness and instruments
Pmc 0.2 m pilot mass center below main karabiners
Mql 8.0 g one quick link mass (riser-lines)
Ycp 0.489 m y-coordinate center of pressure
Zcp 0.299 m z-coordinate center of pressure

Explanations:

g → gravity of Earth (9.80665 m/s2 standard gravity)
ro → air mas density kg/m3
mu → air dynamic viscosity microPascals·s
V → estimated initial flow speed m/s, used for first Cl, Cd, Cm values
Alpha → estimated ideal angle of attack deg. Max glide ratio according wing aerodynamic analysis
Cl → Wing lift coefficient, obtained by analysis with individual profiles, XFLR5, or CFD
Cle → multiplier coefficient of Cl, to consider non-modeled geometries, use 1.0 in case of doubt
Cd → Wing drag coefficient, obtained by analysis with individual profiles, XFLR5, or CFD
Cde → multiplier coefficient of Cd, to consider non-modeled geometries, use 1.15 in case of doubt. If the Cd data comes from CFD this coefficient can be very close to 1.0. Currently studying how this coefficient affects the results. Probably by adjusting through Cde the expected GR, the rest of the parameters will be very close to reality.
Cm → Wing moment coefficient, obtained by analysis with individual profiles XFLR5, or CFD
Spilot → Pilot + harness frontal surface (m2)
Cdpilot → Pilot+harness drag coefficient (depends on the type of harness, especially if have fairings)
Mw → Wing mass (kg) without lines and risers
Mp → Pilot+harness+instruments mass (kg)
Pmc → Pilot+harness mass center distance from main carabiners (m)
Mql → Mass of one quicklink used to connect riser with lines (kg)
Ycp → Y-coordinate of center of pressure (m), obtained by analysis with individual profiles, XFLR5, or CFD
Zcp → Z-coordinate of center of pressure (m), obtained by analysis with individual profiles, XFLR5, or CFD

Remember that the axes used in LEparagliding are:

Origin (0,0,0)= at the nose of the central profile section.
X-axis horizontal and in the span direction
Y-axis along the central chord
Z-axis perpendicular to the XY plane and pointing down (not coincides with gravity axis)

SECTION 36: CREATE FILES FOR XFLR5 ANALYSIS

0 --> don't perform xflr5 analysis
1 --> set parameters for xflr5

* Panel parameters
10 chord nr
5 per cell
1 cosine distribution along chord
1 uniform along span
* Include billowed airfoils (more accuracy) [Still not working]
0

If you use this section, it will automatically be created in xflr5/ directory with a .xwimp file and profiles in .dat format to use in an aerodynamic analysis with the XFLR5 program. The details of how to do it are explained here: http://www.laboratoridenvol.com/info/lep2xflr5/lep2xflr5.html
Unfortunately with XFLR5 we cannot model paragliders with profile rotations in the Z angle, nor single skin paragliders. CFD programs must be used for this type of paraglider.

Type a single parameter "0" to bypass this complicated section!


SECTION 37: SOME SPECIAL PARAMETERS