SPLINE1
Bulk Data Entry Defines a surface spline for interpolating motion and forces for aeroelastic problems on aerodynamic geometries defined by regular arrays of aerodynamic points.
Format
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| SPLINE1 | EID | CAERO | BOX1 | BOX2 | SETG | DZ | METH | USAGE |
Example
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| SPLINE1 | 56 | 33 | 12 | 13 | 11 | 0.0 |
Definitions
| Field | Contents | SI Unit Example |
|---|---|---|
| EID | Unique spline identification number. (Integer > 0) |
|
| CAERO | Aero-element (CAEROi entry ID) that
defines the plane of the spline. (Integer > 0) |
|
| BOX1, BOX2 | First and last box with motions that are interpolated using
this spline. 1
(Integer > 0; BOX2 > BOX1) |
|
| SETG | Refers to the SETi entry that lists the
structural grid points to which the spline is attached.
(Integer > 0) |
|
| DZ | Linear attachment flexibility. Default = 0.0 (Real ≥ 0.0) |
|
| METH | Spline fit method.
|
|
| USAGE | Spline usage flag. 3
|
Comments
- The interpolated points (k-set)
is defined by aero boxes. Figure 1 shows the cells for which
is interpolated, if BOX1
= 326 and BOX2 = 333.
Figure 1. SPLINE1 Entry Example - The attachment flexibility (units of area) is used for smoothing the interpolation. If DZ = 0.0, the spline passes through all deflected grid points. If DZ is much greater than the spline area, a least squares plane fit is applied. Intermediate values provide smoothing.
- The USAGE field allows you to specify that the particular spline interpolant defined in this entry is to be used for both the force transformation and the displacement transformation. Currently, only the BOTH option is supported for the USAGE field.
- The SPLINE1 EID must be unique with respect to all SPLINEi entries.