# Freesbie dynamics

1. Oct 25, 2004

### Gonzolo

Hi,

I'm wondering how difficult it would be to exactly determines a flying disc's trajectory given it's dimensions, rotation, initial velocity and angle of attack.

Can this be done analytically?

What if the lateral angle is also varied? (freesbie not parallel to ground as viewed by person who throws)

Thanks.

2. Oct 26, 2004

### Clausius2

I'm not sure it can be solved analytically. The problem is clearly tridimensional. Pressure variations in trasnversal direction due to the rotation will make the freesbie taking a curved path in a plane xy.

Also, pressure variations in z direction will enhance the lifting force of the freesbie. But in some way it can be simplified supposing the height doesn't vary. And you can simplify the transversal (x,y) movement working out the pressure differences between the inner part and the outer part of the freesbie using Bernoulli if the Reynolds Number is enough larger.

I think that's not a trivial problem at all.