Example Wind File
The following shows the architecture of a wind file (.wnd) file and all the options you can set for a .wnd file. It contains options, logic, and general rules that you must follow when creating a .wnd file.
Example 1 with using options distance or time:
---------------------------------------------------------------------MDI_HEADER
[MDI_HEADER]
FILE_TYPE = 'wnd'
FILE_VERSION = 1.0
FILE_FORMAT = 'ASCII'
$--------------------------------------------------------------UNITS
[UNITS]
(BASE)
{length force angle mass time}
'mm' 'newton' 'degrees' 'kg' 'sec'
(USER)
{unit_type length force angle mass time conversion}
'Nm' 1 1 0 0 0 1E+03
'MPa' -2 1 0 0 0 1
'Nms_d' 1 1 -1 0 1 1E+03
'Nm_d' 1 1 -1 0 0 1E+03
'mm_s' 1 0 0 0 -1 1
$ 1 Nm = 1e3 Nmm = 1 newton*1000mm
$ 1 MPa = 1e6 Pa = 1e6 newtons/M^2*(1M/1000mm)^2 = 1
$ 1 Nms_d = 1e3 Nmms/deg = 1 newton*1000mm*1s/1deg
$ 1 Nm_d = 1e3 Nmm/deg = 1 newton*1000mm/1deg
$------------------------------------------------------WIND_VELOCITY
[WIND_VELOCITY]
ORDINAL = 'distance' || 'time'
(XY_DATA)
{distance <length> || time wind_velocity <mm_s>}*
-10000.00 0.00
0.00 0.00
25000.00 0.00
26000.00 20833.33
50000.00 20833.33
100000.00 20833.33
101000.00 0.00
150000.00 0.00
1000000.00 0.00
$---------------------------------------------------------WIND_ANGLE
[WIND_ANGLE]
(XY_DATA)
{distance <length> || time angle <angle>}**
-10000.00 60.00
0.00 60.00
25000.00 60.00
26000.00 60.00
50000.00 60.00
100000.00 60.00
101000.00 60.00
150000.00 60.00
1000000.00 60.00
*You can select distance or time (should match with the ordinal value specified) and wind_velocity.
**You can select distance or time (should match with the ordinal value specified in wind_velocity block) and angle.
Example 2 with using direct force input:
$---------------------------------------------------------MDI_HEADER
[MDI_HEADER]
FILE_TYPE = 'wnd'
FILE_VERSION = 1.0
FILE_FORMAT = 'ASCII'
$--------------------------------------------------------------UNITS
[UNITS]
(BASE)
{length force angle mass time}
'mm' 'newton' 'degrees' 'kg' 'sec'
(USER)
{unit_type length force angle mass time conversion}
'Nm' 1 1 0 0 0 1E+03
'MPa' -2 1 0 0 0 1
'Nms_d' 1 1 -1 0 1 1E+03
'Nm_d' 1 1 -1 0 0 1E+03
'mm_s' 1 0 0 0 -1 1
$ 1 Nm = 1e3 Nmm = 1 newton*1000mm
$ 1 MPa = 1e6 Pa = 1e6 newtons/M^2*(1M/1000mm)^2 = 1
$ 1 Nms_d = 1e3 Nmms/deg = 1 newton*1000mm*1s/1deg
$ 1 Nm_d = 1e3 Nmm/deg = 1 newton*1000mm/1deg
$---------------------------------------------------------DRAG_FORCE
[DRAG_FORCE]
ORDINAL = 'time'
(XY_DATA)
{time <sec> drag_force <N>}
0 100.014
1 500.014
2 100.014
3 150.014
4 170.014
5 190.014
6 200.014
7 250.014
8 300.014
9 400.014
10 500.014
$-------------------------------------------------------SIDE_FORCE_1
[SIDE_FORCE_1]
(XY_DATA)
{time <sec> side_force_1 <N>}
0 -200.014
1 -200.014
2 -500.014
3 -500.014
4 -1000.014
5 -1000.014
6 -1000.014
7 -1000.014
8 -100.014
9 -100.014
10 -100.014
$-------------------------------------------------------SIDE_FORCE_2
[SIDE_FORCE_2]
(XY_DATA)
{time <sec> side_force_2 <N>}
0 -200.014
1 -200.014
2 -500.014
3 -500.014
4 -1000.014
5 -1000.014
6 -1000.014
7 -1000.014
8 -100.014
9 -100.014
10 -100.014
$-------------------------------------------------------LIFT_FORCE_1
[LIFT_FORCE_1]
(XY_DATA)
{time <sec> lift_force_1 <N>}
0 -100.0
1 -100.0
2 -100.0
3 -110.0
4 -110.0
5 -130.0
6 -130.0
7 -130.0
8 -150.0
9 -150.0
10 -150.0
$-------------------------------------------------------LIFT_FORCE_2
[LIFT_FORCE_2]
(XY_DATA)
{time <sec> lift_force_2 <N>}
0 -100.0
1 -100.0
2 -100.0
3 -110.0
4 -110.0
5 -130.0
6 -130.0
7 -130.0
8 -150.0
9 -150.0
10 -150.0
$--------------------------------------------------------ROLL_MOMENT
[ROLL_MOMENT]
(XY_DATA)
{time <sec> roll_moment <Nmm>}
0 008.0
1 999.0
2 555.0
3 555.0
4 555.0
5 112.0
6 112.0
7 112.0
8 121.0
9 121.0
10 121.0
$-------------------------------------------------------PITCH_MOMENT
[PITCH_MOMENT]
(XY_DATA)
{time <sec> pitch_moment <Nmm>}
0 -300.0
1 -300.0
2 -300.0
3 -200.0
4 -200.0
5 -200.0
6 -200.0
7 -200.0
8 -200.0
9 -200.0
10 -200.0
$---------------------------------------------------------YAW_MOMENT
[YAW_MOMENT]
(XY_DATA)
{time <sec> yaw_moment <Nmm>}
0 153.0
1 -999.0
2 -555.0
3 -237.0
4 -567.0
5 -238.0
6 -589.0
7 -589.0
8 -589.0
9 -589.0
10 -589.0
*You can give direct force inputs to update the gforce_1 and gforce_2 based on type of aerodynamic force you have selected. The existing gforce is updated with force function expressions with splines provided in this wind file.
**If you have selected two point aerodynamic force, then the splines lift_force_2 and side_force_2 are used in function expression.