Structure for the Vortex Lattice Surface tuple = ("Name of Surface", "Value"). "Name of surface defines the name of the surface in which the data should be applied.
The "Value" can either be a JSON String dictionary (see Section \ref jsonStringVLMSurface)
or a single string keyword string (see Section \ref keyStringVLMSurface).
@section jsonStringVLMSurface JSON String Dictionary
If "Value" is a JSON string dictionary (eg. "Value" = {"numChord": 5, "spaceChord": 1.0, "numSpan": 10, "spaceSpan": 0.5}) the following keywords ( = default values) may be used:
-
groupName = "(no default)"
Single or list of capsGroup names used to define the surface (e.g. "Name1" or ["Name1","Name2",...]. If no groupName variable is provided an attempted will be made to use the tuple name instead;
-
noKeyword = "(no default)"
"No" type. Options: NOWAKE, NOALBE, NOLOAD.
-
numChord = 10
The number of chordwise horseshoe vortices placed on the surface. Note: The chordwise count may be overridden using the vlmNumChord BODY attribute on a section.
-
spaceChord = 1.0
The chordwise vortex spacing parameter.
The spacing may be overridden using the vlmCspace BODY attribute on a section.
-
numSpanTotal = 0
Total number of spanwise horseshoe vortices placed on the surface. The vorticies are 'evenly' distributed across sections to minimize jumps in spacings. numpSpanPerSection must be zero if this is set.
Note: The local spanwise count may be overridden using the vlmNumSpan BODY attribute on a section.
-
numSpanPerSection = 0
The number of spanwise horseshoe vortices placed on each section the surface. The total number of spanwise vorticies are (numSection-1)*numSpanPerSection. The vorticies are 'evenly' distributed across sections to minimize jumps in spacings. numSpanTotal must be zero if this is set.
Note: The local spanwise count may be overridden using the vlmNumSpan BODY attribute on a section.
-
yMirror = False
Mirror surface about the y-direction.
-
component = 0
A positive number allows multiple input SURFACEs to be grouped together into a composite virtual surface. Application examples are:
- A wing component made up of a wing SURFACE and a winglet SURFACE
- A T-tail component made up of horizontal and vertical tail SURFACEs.
-
CLaf = 0.0
This scales the effective dcl/da of the section airfoil as follows:
dcl/da = 2 pi ( 1 + CLaf t/c )
where t/c is the airfoil's thickness/chord ratio.
-
CDCL = [CL1, CD1, CL2, CD2, CL3, CD3]
The CD-CL polar is based on a simple interpolation. See AVL documentation for more details.
-
sortVec = [0.0, 0.0, 0.0]
Vector for sorting airfoil sections.
By default, section normals are used for sorting.
However, for LINE sections, a sorting direction is necessary if sorting is desired.
Single Value String
If "Value" is a single string the following options maybe used:
