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Old 03-15-2016, 02:53 PM   #49 (permalink)
aerohead
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Quote:
Originally Posted by gumby79 View Post
https://www.aa.washington.edu/AERL/KWT/rateguide

Based on this your short ancer is 500usd per hr Times 9hr min. [4500usd] and this is the only non phd acceptable meteod
How many hr in the tunnel to get 23% or is this # just as bosga as my 8000mi TEST
*Mercedes-Benz has a supercomputer CFD package that is within 1% accuracy.That's a really good agreement with empirical measurements in their wind tunnel.It requires over 24-hours of run time to calculate a single iteration of body change.
*The DARKO tunnel is $500/hr.
*The A2 tunnel offers a 1st-time users discount at under $500/hr for the 1st 2-hours.
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*Once the vehicle is inside the test section,centered, and strapped down to the load cells,you can accomplish one complete data acquisition run in 4-minutes.
*If you have taped-on mods,you can get quite a few runs in within an hour.
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*there is tunnel-to-tunnel variability as far as drag coefficients go,but we're slowly compiling a comparison list for some of that.
*my truck measured Cd 0.268-0.267 at DARKO.It might have shown Cd 0.244 at A2.Cd 0.218 without the mirrors.
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*my 23% mpg number is just tank mileage.It compares to previous non-boat-tailed highway runs.I have a 22-year, 392,000 mile fuel log database for the truck.
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*I feel like the tunnel data offers the best science we can get.Sure we can learn something from down-hill,or flat-land coasting,and mpg variability,but to really pin it down we need a lab environment like a wind tunnel.
*If you'll read the SAE Handbook requirements for coastdown testing you'll have to catch your breath when you realize what's expected to achieve meaningful results.
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