Hey Interesting program.
I've only played with it for a few moments but I noticed that the wing section seems to be fully symetrical? It will be interesting to have a go with a section with some +ve camber.
Thought I might try a simpler answer to the original question....
>When an aircraft is in level unaccelerated flight, lift equals
>weight.
The vertical component of lift equals weight.
>But, when an aircraft is in an unaccelerated vertical climb, lift
> has decreased to virtually zero - is this so?
yes but... if your plane has a wing section with some camber to it then lift is only zero at a slightly negative angle of attack. So although the plane is climbing vertically the plane and wing will not be pointing exactly straight up.
The same applies in a vertical dive. To get zero lift a plane with a camberd wing has start by pitchig nose down and continue pitching slightly beyond the vertical until the angle of attach is slightly negative.
Note that the program posted above seems to model a wing with a _symetrical_ section. In this case the wing produces zero lift at a zero angle of attack and _will_ point vertically up/down in a vertical climb/dive.
How did I work out that its symetrical section? - by putting it in a vertical dive and noting that Cl =0 when AoA = zero.
Last edited by cwatters; 24th Dec 2003 at 21:05.