CAERO1
Bulk Data Entry Defines an aerodynamic macro element (panel) in terms of two leading edge locations and side chords. This is used for Vortex Lattice Method (VLM) and Doublet Lattice Method (DLM) in subsonic aeroelastic analysis.
Format
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| CAERO1 | EID | PID | CP | NSPAN | NCHORD | LSPAN | LCHORD | IGID | |
| X1 | Y1 | Z1 | X12 | X4 | Y4 | Z4 | X43 |
Example
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|---|---|---|---|
| CAERO1 | 2000 | 2 | 3 | 2 | 1 | ||||
| 1.0 | 0.0 | 0.0 | 3.0 | 0.1 | 0.0 | 0.9 |
Definitions
| Field | Contents | SI Unit Example |
|---|---|---|
| EID | Unique element identification number. No default (Integer > 0) |
|
| PID | Identification number of a PAERO1
property entry.
No default (Integer > 0) |
|
| CP | Coordinate system for locating points 1 and 4. Default = 0 (Integer ≥ 0) |
|
| NSPAN | Number of spanwise boxes. If a positive value is specified, equal divisions are assumed. If zero or blank, a list of division points is specified at the LSPAN field. Default = blank (Integer ≥ 0) |
|
| NCHORD | Number of chordwise boxes. If a positive value is specified, equal divisions are assumed. If zero or blank, a list of division points is specified at the LCHORD field. Default = blank (Integer ≥ 0) |
|
| LSPAN | ID of an AEFACT entry
containing a list of division points for spanwise boxes. This is
used only if the NSPAN field is zero or blank.
Default = blank (Integer > 0) |
|
| LCHORD | ID of an AEFACT entry
containing a list of division points for chordwise boxes. This is
used only if the NCHORD field is zero or blank.
Default = blank (Integer > 0) |
|
| IGID | Interference group identification. Aerodynamic elements with
different IGIDs are uncoupled. (Integer > 0) |
|
| X1, Y1, Z1 | Location of point 1 in coordinate system CP.
(Real) |
|
| X4, Y4, Z4 | Location of point 4 in coordinate system CP.
(Real) |
|
| X12, X43 | Edge chord lengths in aerodynamic coordinate system. (Real ≥ 0.0, but both fields should not be zero at the same time) |
Comments
- The boxes and corner point nodes are numbered sequentially, beginning with EID. Be careful to ensure that all box and corner point node numbers are unique. There can be overlapping IDs between the structural and aerodynamic model, but result visualization will be affected. Similarly, non-unique corner IDs are allowed, but results cannot be visualized.
- The number of division points is one greater than the number of boxes. Therefore, if NSPAN = 3, the division points are 0.0, 0.333, 0.667, 1.000. If division points are specified, the first and last points do not need to be 0.0 and 1.0 (in which case, the corners of the panel would not be at the reference points).
- A triangular element is formed if X12 or X43 is set to 0.0.
- The element coordinate system is
right-handed.Span direction is in Ye (1 to 4), and Chord direction is the Xe (from 1 to 2 or 4 to 3). First box ID of a panel is the same as the CAERO1 card ID. Then chordwise, the ID is incremented by one for subsequent boxes. After each chordwise strip, go back up to the next box along the span at the beginning of the panel and repeat the process.
Figure 1. Element Coordinate System for Aerodynamic Panel - The continuation line on the CAERO1 entry is mandatory.