11-01-2011, 08:14 AM
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#31 (permalink)
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Master EcoModder
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Quote:
Originally Posted by jimepting
I second the thanks to Darin. We have a wonderful site, largely through his hard work!
When you start making videos with that 7-meg camera, set the resolution as low as your can, and keep the segments to an absolute minimum length. Otherwise it takes forever to get it uploaded to youtube. Powerful tool, but needs some discipline  |
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Thinking this through a bit more, I think I misled you on this statement. Reason my upload was so slow is that I use an air card to connect and it only runs at 100kb/s or so. Sorry 
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11-01-2011, 09:09 AM
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#32 (permalink)
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Batman Junior
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Quote:
Originally Posted by jimepting
I second the thanks to Darin. We have a wonderful site, largely through his hard work!
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Nah - I haven't done any hard work in years! 
If anyone deserves praise for making EcoModder wonderful, it's the members in general. |
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11-01-2011, 07:38 PM
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#33 (permalink)
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Master EcoModder
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Quote:
Originally Posted by jimepting
I was amazed that the turbulence did not get worse further back on the hatch. I had been conditioned to think that flow deteriorated as one got closer to the rear edge.
All very interesting. Seems Honda got it pretty much right.
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If you haven't seen it before ... you can also see it in the wind tunnel video bellow ... if you haven't already seen it before ... even if there is only a short piece of the video showing it.
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The Following 7 Users Say Thank You to IamIan For This Useful Post:
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11-01-2011, 08:05 PM
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#34 (permalink)
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Cyborg ECU
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Quote:
Originally Posted by IamIan
If you haven't seen it before ... you can also see it in the wind tunnel video bellow
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Not much for the back window, but there is an interesting moment at 2:05 for the driver's rear view mirror. Seems to be a giant turbulent zone that explodes around and behind it. I know the mist does not tell a lot and that it can be manipulated in video. What does the video suggest to you?
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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11-01-2011, 10:17 PM
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#35 (permalink)
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Batman Junior
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Quote:
Originally Posted by IamIan
If you haven't seen it before ... you can also see it in the wind tunnel video bellow
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Wow - that's instructive!
Phil's right when he said Honda took the rear hatch curvature to the ragged edge - the boundary layer looks like it practically triples in thickness between the top of the hatch and the tail end - without separation rearing its ugly head. |
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11-01-2011, 10:35 PM
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#36 (permalink)
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Master EcoModder
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Quote:
Originally Posted by IamIan
If you haven't seen it before ... you can also see it in the wind tunnel video bellow ... if you haven't already seen it before ... even if there is only a short piece of the video showing it.
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It is an amazing video. I'm sure I'll spend hours watching it.
What does the thickening of the smoke trail mean in practical terms. Obviously pressure is being lost, but since it stays attached, do we interpret this as a negative for this car length? For boat tails, should we try to raise the hatch a couple of degrees, by some means? |
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11-01-2011, 10:42 PM
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#37 (permalink)
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Batman Junior
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I wouldn't go to the trouble of trying to raise the hatch, but in terms of making a boat tail, I would not continue increasing the curvature much beyond the last "angle" at the end of the hatch.
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11-02-2011, 06:21 PM
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#38 (permalink)
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Master EcoModder
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camera viewpoint
Quote:
Originally Posted by IamIan
If you haven't seen it before ... you can also see it in the wind tunnel video bellow ... if you haven't already seen it before ... even if there is only a short piece of the video showing it.
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It would have been beneficial had the camera shot from roof level rather than the beltline.
All in all,its a glimpse into a controlled access environment.Thanks for the look! |
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11-02-2011, 06:39 PM
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#39 (permalink)
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Aero Wannabe
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I wish my Japanese weren't so rusty but I am sure they said several times the Cd is 0.25.
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60 mpg hwy highest, 50+mpg lifetime
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Quote:
Originally Posted by freebeard
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
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11-02-2011, 06:50 PM
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#40 (permalink)
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Master EcoModder
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Quote:
Originally Posted by aerohead
It would have been beneficial had the camera shot from roof level rather than the beltline.
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Agreed ... But I have not found other wind tunnel videos yet... although I have no doubt hours of such video exist from every angle ... until someone finds other videos ... all we can do is more cost effective things like the Tuft testing, and cost down testing.
Quote:
Originally Posted by aerohead
All in all,its a glimpse into a controlled access environment.Thanks for the look!
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welcome.
Quote:
Originally Posted by California98Civic
Not much for the back window, but there is an interesting moment at 2:05 for the driver's rear view mirror. Seems to be a giant turbulent zone that explodes around and behind it. I know the mist does not tell a lot and that it can be manipulated in video. What does the video suggest to you?
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Suggests the same thing to me ... which is what I would expect , given the shape of the side mirror ... but it is what people expect ... to have side mirrors ... and alternatives to keep the same functionality without the aerodynamic hit of the current design , would cost significantly more ... for a side mirror the current OEM design is not bad , and it is only a small % of the total vehicle frontal area.
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