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Old 07-06-2020, 01:41 PM   #68 (permalink)
aerohead
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ground effect,ROI,no advantage,............

Quote:
Originally Posted by Engeu1 View Post
Presumably due to ground effect and weather at ground level? Equally, that should not rule out positive results around ideal conditions.



But it's a matter of net cost-benefit.



No, but that doesn't mean there is no advantage in constraining turbulent flow.



In the academic realm that makes sense. In the commerical realm, if something works satisfactorily and sells, there may be no advantage to explaining it further. The product is SmartWay Verified for a modest benefit. A better approach would be to look at the EPA verification method and diligence.
1) mounting next to a wall of turbulence, and perhaps fully embedded within the turbulent boundary layer of the trailer van or truck box to begin with, would violate the 'flight conditions' on which an auxiliary airfoil would rely for its performance.It's not on an aircraft, with air moving 'above and below' it.
2) 'Ideal' conditions include an empirically-observed, statistical mean averaged 7-mph ( 11.3 km/h ) crosswind, within Earth's own turbulent boundary layer ( measured in kilometers, not meters, or millimeters, and in train of vehicular turbulence.
3) Physics is physics, and probabilities of yaw-related performance degradation have been measured from real-world observational data and common practice statistical analysis.It doesn't have good days and bad days.
4) I don't know how one conducts a life-cycle-cost-analysis with performance claims of dubious merit.
5) If you can, in your own words explain the drag reduction mechanism associated with 'constraining' turbulent flow it would be greatly appreciated. I'm forever a student of road vehicle aerodynamics.
6) As to consumer behavior in the commercial marketplace, I'm uncertain as to how much product research goes into the sales dynamic. There are no shortages when it comes to charlatans eyeing a consumer's pocketbook. ' Smartway Verified' has absolutely no meaning or credibility that I'm aware of.
7) NASA Ames Research Center, Palo Alto, California, USA, is the only wind tunnel large enough to accurately test 'Rocketail'. Any claim based upon CFD results would have to be verified at a facility such as NASA's.
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