Senior Space Cadet
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- Joined
- May 23, 2020
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I guess I still have a lot to learn.
I almost always have the fin as far back as it can go, without the root extending past the body tube. Assume that for the following.
I noticed a long time ago that, while keeping the tip chord relative (I usually make it half the root chord), shortening the root chord moved the CP back.
At first that seemed counter intuitive, since the surface area of the fin was being reduced. It still seems a little counterintuitive, though I realize it must be because the CP of the fin, by it's self, has moved back.
My spinner rocket design was proving problematic so I was just working on another design with six fins.
I'd picked a root chord and, normally, I would just make the height the same or pick something that looked good.
But this time I was watching the stability number as I increased the fin height and noticed that at some point the stability started to go down.
I'm at a loss for understanding why the stability would go down with an increase in fin height.
I almost always have the fin as far back as it can go, without the root extending past the body tube. Assume that for the following.
I noticed a long time ago that, while keeping the tip chord relative (I usually make it half the root chord), shortening the root chord moved the CP back.
At first that seemed counter intuitive, since the surface area of the fin was being reduced. It still seems a little counterintuitive, though I realize it must be because the CP of the fin, by it's self, has moved back.
My spinner rocket design was proving problematic so I was just working on another design with six fins.
I'd picked a root chord and, normally, I would just make the height the same or pick something that looked good.
But this time I was watching the stability number as I increased the fin height and noticed that at some point the stability started to go down.
I'm at a loss for understanding why the stability would go down with an increase in fin height.