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Old 09-15-2022, 11:37 AM   #18 (permalink)
aerohead
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Think Flight Subaru = approx. Cd 0.156 potential

I froze the screen of the video, and Al captured it on a memory stick, then printed out 11" X 17" copy, at the scale of my x-ray overlays.
Using the dimensions of an Outback, the Think Flight came in at approx. 252" overall length, a 60" elongation.
Length / Height = 3.7672
Length / height = 4.2637
Length / width = 3.3753
Length / three-ratio average = 3.80206
Af estimated @ 85.5% of gross frontal area = 29.656 sq-ft.
Length / square-root of Af = 3.8562
forebody = 49.5% of L
Aft-body = 50.5% of L
The elongation effectively creates a 'double-ended' body
Verungungsverhatnisse ( V ), ( aft-body length / h ) = 2.1654
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I found six cars with L / square-root of Af similar to Think Flight. Cds ranged from 0.20, to 0.137, with a 6-car average of Cd 0.1568.
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I found six cars with V similar to Think Flight. Cds ranged from 0.19, to 0.137, with a 6-car average of Cd 0.1558.
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The comparison cars are:
1983 GM Aero 2002 concept
1984 GM Chevy CITATION-IV concept
1985 Ford PROBE-V concept
1993 GM EV1 LSR
2006 LOREMO
2016 M-B IAA concept
2017 Eindhoven University Stella Vie
2019 GAC ENO. 146
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With all- wheel- skirts, wheel covers, a full belly pan, diffuser, and 'corrected' boat-tail, there's a high probability that Think Flight would indicate near Cd 0.156 or less.
About a 50.9% drag reduction.
And 'back of the napkin' mpg improvement, at 65-mph, of 25.5%, or around 44.5-mpg.
If the same mods were applied to the 2023 Subaru Solterra BEV, we'd be looking at around 155-mpg-e.
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PS, before I forget, I measured a 19-degree downslope angle on top.
TF reported that he used 20-degrees for the sides.
I measured 20.5-degrees for the diffuser.
The upper profile is very similar to Mair's 1969 torpedo, Volkswagen's 1981 'Flow-Body', and the 2007 AST-I contours.
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PPS, over the weekend I'll go over the Subaru Impreza Wagon specs now that I have them.
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Last edited by aerohead; 09-15-2022 at 05:17 PM.. Reason: add PPS
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