Quote:
Originally Posted by freebeard
Thanks. That answers my question about the road only rolling between the wheels. So at least the area around the tire contact patch is modeled correctly.
The weight sensitive posts don't attach to the spinning wheels? Do they attach to the sprung or unsprung weight?
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The whole model (what we would call sprung weight) rests on the pegs. The suspension does not support the model; it is just effective enough to keep the wheels from bouncing on the rollers.
Quote:
Originally Posted by darcane
Very cool! That would have been fun. I once toured GM Powertrain Headquarters and got to see several new engines before they were released.
One little quibble...
I get that you are trying to simplify in layman's terms that the Reynolds number needs to be constant to compare the results on the model to that of the real car. However, it doesn't really make sense to me to state that the model gets hit with 1/3rd as many air particles. Keep in mind the frontal area of the model is 1/9th (1/3rd height x 1/3rd width) of the full size car. Scaling up the speed really has more to do with the fluid in the boundary layer acting over the length of the model. Since the characteristic length is 1/3rd as long, the speed has to be 3 times as great.
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I work in "secret" every day, so it was refreshing to finally be allowed to share something.
That is how the engineers explained it. There's a lot of complicated math out there, and that explanation helped me visualize it and finally kind of understand what's happening. Whatever the actual numbers and ratios are, it gets the point across.
Quote:
Originally Posted by kach22i
Nice blog post, wonderful of GM to allow you to publish this.
Did you have to get model releases signed?
Aero sculptors................brilliant term, one I have not read before.
Thanks for posting this.
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Yes, fun to take some photos. I wasn't part of any select group and I'm not getting paid for the blog so I didn't get any releases. We were encouraged to take pictures and video; I'm sure GM loves the PR.
Aero sculptors... ha. When you're testing a physical model, you have to physically change it to test ideas. So you get people working in clay. I don't know if they come mostly from the aero side or sculpting side, but a lot of our sculpting staff in Design comes from a fine arts background.
My pleasure.