9.3: Input Chord of Airfoil
Use the input field 'chord [m]' to change the length of the chord line. Enter
the desired length in meter. The reference point for chord length is the
leading edge of wing.
Near the input field are Up/Down-buttons located. They can be used to change
the length of the chord line with mouse clicks.
A click on the right mouse button pops up a menu to set the increment between 0.00001m
and 1m.
Please notice the following:
The length of the chord line is always altered at that segment edge, which
shows - seen from the wing centre - to the wing tip. The following picture
illustrates this strongly exaggerated. The reference point for chord length is
in this example set to 0% (leading edge).
The reference point for chord length can be changed in the input field
'Reference point chord [%]'. Valid values lie between 0% and 100%. 0% means the
leading edge of wing, 100% means the trailing edge.
Near the input field are Up/Down-buttons located. They can be used to change
the reference point with mouse clicks.
A click on the right mouse button pops up a menu to set the increment between 0.00001%
and 1%.
There is a third method to change the value. Move the mouse cursor into the
input field and click the right mouse button.
A pull-down menu pops up and offers the pre-set values 0%, 25%, 50%, 75%, 100%
for quick selection.
The following pictures illustrate the function of the reference point. The
first picture shows a wing with four segments and a constant chord length of
0.2m.
In the second picture the length of chord was
change to 0.4m for both outer segments. For the left segment, the reference
point was set to 100% (trailing edge) while it was set to 0% (leading edge) for
the right segment.
The 'Reference Point for chord [%]' can be set on
the folder 'Wing' in the area 'Wing Root' as well as in the area 'Segment' and
is always applied to the entire wing.
It is impossible to set different values for
individual segments. This functionality serves only for fast entry of
geometries. The value entered in the area 'Wing Root' is copied into newly
created segment. While optimizing wing geometries these values can be set in
every segment for the wing. The computations will be recalculated for the whole
wing accordingly to the changed values.
These values can be changed as often as necessary for optimization.