How do drag and angular drag interact?

Question

I'm simulating a truck with a trailer, and I'm working on making sure the trailer rotates in a realistic way. What I'm wondering is how both drag and angular drag will act on the trailer as it fishtails behind the truck. I would think that angular drag is what would slow down the fishtailing, as I'm trying to reduce the trailer's rotation. At the same time, I could also see how regular drag would reduce the fishtailing movement as well.

What I want is for the trailer's rotation to trail behind the truck's when it starts turning, then overshoot it as the truck straightens out, then slowly return to being directly behind the truck as the truck drives straight. After doing a little testing, I've found that regular drag simulates that the best, though I'm not really sure why. If I just use angular drag, the trailer will rotate to be at a 90 degree angle with the truck and then stick there, while using both angular and regular, or even just regular, makes it do the fishtailing behavior I'm looking for.

Any ideas why?

Answer 1

Answer by AdamBL · Feb 16, 2017 at 10:22 PM

So I've done a little testing, and it seems like angular drag is actually the bigger factor here. I did 3 trials where I accelerated for 3 seconds, turned for 3 seconds, then saw how long it took for the trailer to return to the "default" state (as well as how many fishtail swings it took):

Drag = .5, Angular Drag = .5 : 26.7 seconds, 5 fishtail swings

Drag = 1, Angular Drag = 0 : 39.3 seconds, 8 fishtail swings

Drag = .25, Angular Drag = .75 : 20.2 seconds, 3 fishtail swings

In general, lower drag gave a bigger initial fishtail, though that might've been because the truck was going faster due to the decreased drag.

Add comment · Share

Answer 2

Answer by Judgeking · Mar 08 at 01:32 PM

For future ref:

The linear drag applies to positional movement and is set up separately from the angular drag that affects rotational movement. A higher value of drag will cause an object's rotation to come to rest more quickly following a collision or force.

Add comment · Share

How do drag and angular drag interact?

2 Replies

Your answer

Follow this Question

Related Questions