How to simulate a knuckleball (soccer)?

I want to simulate the aerodynamics of the knuckleball phenomenon on a soccer ball. Drag (indicated with a blue arrow) and magnus (indicated with a yellow arrow) forces are already present in my current simulation as shown in the following video.

The issue is that I have not succeeded in calculating the lift force. The physics behind the lift force for a ball is quite complicated.

I read some scientific papers to look for models to calculate the lift force. The best paper I found is this one: ‘ShieldSquare Captcha’. However, I cannot solve the lift force equation that is provided by the paper (stuck at Equation 6). I am looking for either an alternative way to calculate the lift force or a clarification on the paper’s approach.

This question might not suit this community, but I figured it is worth a try.

As i understand it knuckleball physics events are caused by airflow acting on the seams of a ball, so its a very rare event, caused when the ball has low or no rotation and its seams align with oncoming wind, thus producing a wing type effect where air passes over one side of the seam faster then the other side, thus forcing the ball to zig zag…
But tbh putting randomness in a football game doesnt sound that fun…unless you make it a type of rubber-banding, like in NBA jam where your players skill depends on how much the score differs… So maybe if a team is winning turn knuckleball physics on so that it both makes it harder to score but also makes it so that if you score it looks amazing???
Rubberbanding Video:> How NBA Jam cheats against you | MVG - YouTube
Lol offtopic but im still reading through the article

It is just a nerd project of mine and not really a game. I might turn it into a game later, but I just wanted to implement some crazy physics for fun.

That is true, since it only occurs when the ball hits high Reynold numbers (with a lot of speed) without rotating much.

Well as far as i can work out its all in that paper, you’ve just to get your head round it, cos i cant XD, you might do better asking for help on a real physics forum…Since this is like proper aerospace engineer quality stuff…

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The paper is from 2016, which really shows how hard it is to model a knuckleball trajectory. I might try to ask this question on a physics forum.

yeah defintly get a real physicist on this :smiley:

yes get a real physics man on this

My best bet is to replicate the maths from ‘https://iopscience.iop.org/article/10.1088/1367-2630/18/7/073027’.

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