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Old 01-27-2013, 12:22 PM   #81 (permalink)
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ChazInMT- the way i understand it, the top view that you're depicting is different than looking a the car from the side. unlike from the side, the top view is not in a ground plane and it therefore not a half body but a full body of rotation. When the car pushes the air molecules around the car, they go up, left, and right. Aside from slight underbody flow, these are the three planes for the air molecule to move in(excluding swirly and moving forward and backward). Therefore, there must also be 3 seperate planes to allow the air to snap back into place behind the vehicle.

To determine where to place the template, you align the bottom of the template with your stagnation point(in this case, the middle of the car splits flow to both side) and then the you align the top with the point of max side camber. When looking down at the car, you want it to look like a tear drop.

On the side view, the reason the bottom of the template is not placed directly on the stagnation point is because the underbody flow is not considered. Therefore, the ground plane becomes the stagnation point.

The method you've been using does not hurt, but you might not be reaching you full streamlining potential. it's always safer to go longer than it is to go shorter.

Hope this all makes sense. It's the way I've interpreted the streamlining information and I've yet to earn my high school diploma, so I could be wrong.

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Old 02-01-2013, 09:45 AM   #82 (permalink)
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I have done some overlayes conserning my roof chopping and this is bothering me this is correct overlay and its way off:

If I put it about 250-300mm too toward the front it layes perfectly:


So the guestion follows:
If you put the template too much in front of the picture is still layes perfectly ok to the shape. So can I do the same in my lupo and still get nice flow. My own estimation is that when you are at the max roof camber you can make that first few degrees pretty rapidly like those pictures prove or what do you think?

This may be true only if you begin the cambering at the max camber point etc?

third option:


Now template aligned at car underside lowest level and its quite nice match on the roof. Note that sidesills are lower than the cars underside, because its better aerodynamically that way...
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Old 02-06-2013, 08:06 PM   #83 (permalink)
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Quote:
Originally Posted by 2000neon View Post
I'm shocked, I had no idea that the tapered in that much at the top of the cab. Now I'm wondering if that is just this generation of truck, or all of them. Now I want to see one on the road to take a closer look at one.

Of course this is all assuming that I've applied the template correctly, if I have not, I will gladly accept criticism and advise on how to do it better.
Yep, my truck is basically identical to that. (so will all 02/03-08 RAMs) The doors slant in from the bottom of the windows up... But seeing the template applied like you did really brings it out!

[edit] Vekke, if you have modded your vehicle to that shape, nice work. I'll defer on the template match to those more acquainted with it...
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Old 02-17-2013, 05:30 AM   #84 (permalink)
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Chopping process under construction. Starts to be quite close to correct angle .

https://www.facebook.com/photo.php?f...type=1&theater

How about some half meter extesion at the same time while doing it?

For the template software gurus, if you are able to make it so than when you make pictures smaller or bigger the lower edge would stay in the same level. That would help a little to get it proper size faster. But big thanks for this version also, already much faster than with paint .
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Old 02-17-2013, 11:31 AM   #85 (permalink)
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"Proportional (equal X & Y reduction/increase) Scaling"!!!
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Old 02-19-2013, 05:19 PM   #86 (permalink)
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Quote:
Originally Posted by Old Tele man View Post
"Proportional (equal X & Y reduction/increase) Scaling"!!!

???
Don´t want to sound rude, but what does it mean? Could you explain it better? Post some example? Do a proper bug report?


Quote:
Originally Posted by Vekke View Post
[snip] if you are able to make it so than when you make pictures smaller or bigger the lower edge would stay in the same level. That would help a little to get it proper size faster.[snip].
As for ground plane alignment kept while resizing - I have already tried but it was too much fuss for problematic result. I will give it a try one more time though.
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Old 02-25-2013, 03:19 AM   #87 (permalink)
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Quote:
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As for ground plane alignment kept while resizing - I have already tried but it was too much fuss for problematic result. I will give it a try one more time though.
I did some tinkering and came up with this. It's not perfect, but I need to sleep. Ground plane alignment should at least be close enough that you don't have to adjust every time you zoom one step, so I'm willing to call it a good enough solution for the time being.

weirdcalculator.com/test/aero_template


For the future:
  • I'm fairly sure I got the calculations right, but it still jumps around a little due to rounding. Also, I'm pretty sleepy, so there's a chance I might have messed something up terribly. I will revisit this issue.
  • The ground is not at the same height (from top) in the two templates, so I will likely have to resize one to make them both work right.
  • For anyone with side shots that aren't exactly level, I have a CSS trick up my sleeve so you won't have to use photo editing software to get it to line up. I will try to get around to implementing it this week (shouldn't be as difficult as the ground plane problem, as I have already done most of the work for another project).
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Old 02-25-2013, 08:53 AM   #88 (permalink)
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As long as you aren't sleeping....

Could you make a button to make one image or the other a negative? The black template outline often fades into the black background of many car images.

Not an absolute need, just something I have noticed.
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Old 02-25-2013, 12:10 PM   #89 (permalink)
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Quote:
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As long as you aren't sleeping....

Could you make a button to make one image or the other a negative? The black template outline often fades into the black background of many car images.

Not an absolute need, just something I have noticed.
Well, now that I've had some sleep, I was able to take care of this one. I also changed some of the code around so that there are still only four template versions instead of 8 (in case of slow connections). Getting ready to work on the rotation part now.
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Old 02-25-2013, 09:26 PM   #90 (permalink)
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Quick service! Already tried in on one on my RV pictures with a black background, works great.

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