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Old 07-07-2021, 02:04 PM   #1 (permalink)
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Methods of Reducing Vehicle Aerodynamic Drag

I'll try for a link to this work by Upendar Rohatgi, at Brookhaven National Laboratory.
https://www.researchgate.net/publica...rodynamic_Drag
The particulars I was most interested in had to do with boat-tailing a full-size GM SUV.

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Old 07-07-2021, 04:54 PM   #2 (permalink)
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I'm also reading that he wasn't able to get any significant improvement (or change at all) with vortex generators.
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Old 07-07-2021, 04:57 PM   #3 (permalink)
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First mention of a perforated base plate I've seen in a while.

One quarter the benefit with one tenth the cost, weight and operational pain.
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Old 07-07-2021, 05:12 PM   #4 (permalink)
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VGs

When Gary Wheeler first went public with his Air Tabs VGs, it was within the context of providing for flow re-attachment onto the boot of a notchback car. He used his own Honda as an example.
Without some surface to re-attach to, I've no idea why anyone would have any expectation for improvement.
https://ecomodder.com/forum/member-a...s-air-tabs.jpg
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Old 07-07-2021, 05:52 PM   #5 (permalink)
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Cheat sheet for the lazy...



CONCLUSSIONS


Quote:
1. Use of rear screen allows a reduction in aerodynamic drag of the vehicle model under consideration by up to ~6.5%. Efficiency of rear screens from point of view of drag reducing equally depends on configuration, dimensions and arrangement of screens as well as on model’s rear part configuration. The external mount of spare tire can be arranged to reduce drag.
Quote:
2. Rear fairing as part of flow separation area behind the vehicle can reduce aerodynamic drag of the vehicle with investigated configuration, by up to 26%. These results can be used at analysis of accuracy of calculation methods for defining aerodynamics of vehicles with separated areas. The results can also be useful for designers and design engineers in selection of vehicle external configuration.
Quote:
3. The other passive options also have potential to reduce drag. Front structural elements showed decrease in drag coefficient up to 2.24% and vortex generator showed a decrease up to 1.24%. There is scope to achieve additional improvement with the understanding of flow field and optimization of design.



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Old 07-07-2021, 07:15 PM   #6 (permalink)
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Quote:
CONCLUSSIONS
Is that like a realization that smacks you upside the head?
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Old 07-07-2021, 07:20 PM   #7 (permalink)
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conclussing the mind

That's exactly what I need!
If it takes a little shockwave to embedded, so be it.
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Old 07-07-2021, 09:28 PM   #8 (permalink)
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Woodie Guthrie has had his run in my signature.

redneck -- You want credit for that?
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Old 07-07-2021, 11:48 PM   #9 (permalink)
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🤷

Not my job to proofread and correct published papers.

All I did was copy and paste.



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>

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