Notes for the aerofoil example.

1, remember to label the vertex G, you will frequently need to highlight this vertex.

2, better to create the faces after having linked all the edges.

3, when count the Elements of edge IG (may also JG), pay attention the number displayed on your screen. I got 35 rather than 36.

4, for some version of Gambit, you may not allowed to choose the 'Last length' option when meshing an edge, then try 'First length' and also reverse the direction of edge by using 'Shift+middle click' or left click the 'Reverse' botton on the Gambit interface.

When you attempt to generate your own airfoil geometry, e.g. from http://www.ppart.de//programming/java/profiles/NACA4.html, note the points below.

5, after having chosen the 'Maxium Camber', 'Max Camber Pos.', 'Thickness' and 'Points' (e.g. 66), left click Show Points, choose all the data in the right box, copy & paste to a text editor, e.g. notepad. Unfortunately, you will only get 65 + 65 points. See the raw data.

6, then try to modify the above data file to suit for Gambit. This is the final one. First line indicate 66 points per curve, 2 curves. Gambit needs X, Y, Z coordinates anyway. So I insert a third colume -all zero. I inserted two more points --1 0 0 after the line 62 0; and 0 0 0 after the line 0 0 0 (in the middle of the columes). I changed the last points from 1.0 -7.349999999999871E-4 to 1 0. Now have 66 points per curve.

Why to make these changes?

7, The leading edges or the trailing edges of the two curves must have the same coordinates (i.e. 0, 0 or 1, 0).

8, the top and bottom curves must have excactly same number of points (i.e. here is 66). Seems Gambit is not happy to have more than, say 100 points per edge (I can not remember the limit now, you may want to have a try).

Updated: 15-Oct-2008