Recent content by Eric_T

Sorry, I didn’t mean the shot was unpredictable and due to wind gusts, just that it’s different since the disc is transitioning through zero speed at one point. I don’t think you can convince me that there are other ways the disc can change its attitude other than gyroscopic precession, though :)

I meant in the sense that the torque you would impart on the disc to give it spin would instead be used off-axis, assuming conservation of momentum. But you are right, with biomechanics we cannot definitely say that momentum is conserved in this sense.

Thanks, I really appreciate it! Yes, I could probably publish something on this, and I have been thinking about writing something like a summary of all the discussions here, but that requires a lot more rigor and attention to detail, haha. It's nice to have some outlets for my work which is more...

I forgot to reply to this. Yes, the MTA stuff is pretty cool. I think it's a different situation, though, as in such a shot the disc slows down all the way to zero at the peak. Then can flip around many different axes depending on where it goes after that point.

Yes, I guess the increased turn can give more distance in some cases. But like you point out, then there would be another line, or another disc, that would give you even more distance. And like I said before, I have some concerns on how the TechDisc simulator handles this. I doubt they have...

Alright, so I did some pretty complex computational fluid dynamics calculations including wobble, and the results are very interesting! It seems my hypothesis that wobble doesn't create extra turn was wrong. First off, here is a visualization of the simulation with wobble, where red color is...

It seems weird to me that the sign of the initial wobble angle should cause different flight. Wobble is measured by the angle of the disc relative to the disc’s local rotational axis. It only makes sense as a measure at the point of the release. As the disc rotates, or wobbles, it will move...

Thanks for adding to the discussion, Chris! It would be really cool to have 3D tracking of the throws, with something like a TechDisc in an open field. Benji, just to clarify one thing regarding the plots. You say the disc is moving right for a long time before hitting the apex, but it actually...

It's hard to tell from these video angles, and it's also downhill, but I think the trajectory is actually flatter than it seems towards the end, it doesn't really flare out. Here's another example from a distance competition, that seems to match my result: The apex of the flight is roughly at...

I haven't looked at the wobble part of the dynamics yet, but it's a really interesting question. The wobble definitely means that angular momentum is transferred between the axes, but not sure if you can say that you need to take momentum from the spin to damp the wobble. But the off-axis torque...

First of all, thanks for questioning my results, it helps to think about things from different perspectives, and maybe we can discover some new things. You have to be careful with that Lissaman paper, though, what they do there is look at what an idealized lift input would give. In the third...

I think I understand what you are suggesting, but I'm not sure I have seen that type of behavior in a throw. Do you have an example from disc golf coverage or something? I tried looking at some distance competations now, and the throws look very much like what I get from the simulator. One...

I did a few more simulations of this, and the results are pretty interesting. As you say, the disc will level out during the flight. Think of an air bounce throw, for instance, even with an extremely high nose angle the disc will eventually change its trajectory and start flying more straight...

Thanks for the input. It's an interesting theory with the nose angle, but I think what you say here is actually sufficient to explain the optimal trajectory. Like you say a wings-level approach would be optimal, so we need to try to approximate that. By having the disc at an anhyzer angle and...

Yes, it's about trying to spend as much time as possible in "glide-mode", letting the disc drift with high lift force throughout the flight. Here is one of the optimized throws I was talking about, throwing a nuke at 70 mph (with the usual caveats about uncertainties etc): This is thrown...