Elliptical Tube flat pattern
What it is
The elliptical tube is a shell of elliptical section: the development is rectangular, like a cylinder, but the length comes from the perimeter of the ellipse, which has no closed form and is obtained by numerical integration along the outline.
Where it is used
Ventilation ducting in restricted height where the flow area must be kept; oval fairings and structures.
Measurements the calculation needs
- X Overall width of the ellipse
- Y Overall height of the ellipse
- H Length of the tube
- DV Divisions
- THK Plate thickness
Calculate with your own measurements
No account needed: enter the measurements in millimetres or inches and get the figures and the drawing. The scaled PDF template, the DXF for the cutting table and the 3D model take a free account.
Diameters and sides are outside measurements. The flat pattern already allows for the plate thickness, working on the mean line.
Units: mm inches
Worked example
The values the form comes pre-filled with, run through the tool itself:
| Overall width of the ellipse | 39-3/8" (39.3701) |
|---|---|
| Overall height of the ellipse | 19-11/16" (19.685) |
| Length of the tube | 31-1/2" (31.4961) |
| Divisions | 32 |
| Plate thickness | 1/16" (0.0394) |
| The flat pattern fits a plate of | 95-1/4" × 31-1/2" |
Result of the example
| Plate | 95-1/4" × 31-1/2" |
|---|---|
| Area and weight | 20.8 ft² · ≈ 33.5 lb in 1/16" steel |
Ordinate table
| # | Position on the plate | Element height |
|---|---|---|
| 1 | -95-1/4" | 31-1/2" |
| 2 | -91-3/8" | 31-1/2" |
| 3 | -87-11/16" | 31-1/2" |
| 4 | -84-1/8" | 31-1/2" |
| 5 | -80-15/16" | 31-1/2" |
| 6 | -78-1/16" | 31-1/2" |
| 7 | -75-9/16" | 31-1/2" |
| 8 | -73-3/8" | 31-1/2" |
| 9 | -71-7/16" | 31-1/2" |
| 10 | -69-7/16" | 31-1/2" |
| 11 | -67-5/16" | 31-1/2" |
| 12 | -64-13/16" | 31-1/2" |
| 13 | -61-15/16" | 31-1/2" |
| 14 | -58-3/4" | 31-1/2" |
| 15 | -55-3/16" | 31-1/2" |
| 16 | -51-7/16" | 31-1/2" |
| 17 | -47-5/8" | 31-1/2" |
| 18 | -43-3/4" | 31-1/2" |
| 19 | -40-1/16" | 31-1/2" |
| 20 | -36-1/2" | 31-1/2" |
| 21 | -33-5/16" | 31-1/2" |
| 22 | -30-7/16" | 31-1/2" |
| 23 | -27-15/16" | 31-1/2" |
| 24 | -25-3/4" | 31-1/2" |
| 25 | -23-13/16" | 31-1/2" |
| 26 | -21-7/8" | 31-1/2" |
| 27 | -19-11/16" | 31-1/2" |
| 28 | -17-3/16" | 31-1/2" |
| 29 | -14-5/16" | 31-1/2" |
| 30 | -11-1/8" | 31-1/2" |
| 31 | -7-9/16" | 31-1/2" |
| 32 | -3-7/8" | 31-1/2" |
| 33 | 0" | 31-1/2" |
Guides about this part
Frequently asked questions
- How does this differ from the oval tube?
- An ellipse is a continuous curve whose radius changes at every point. The oval tube is two semicircles joined by two straight runs. They are different sections and do not substitute for one another.
- Are X and Y the axes or the semi-axes?
- The full axes: the overall width and height of the ellipse.
You can work out the figures right here, with no account. PDF, DXF, 3D and history take an account — free, with unlimited calculations.