Quote:
Originally Posted by JulianEdgar
So if tiny wind tunnels without moving wheels are all that's needed, car manufacturers have chosen to build huge wind tunnels just because they like spending money? I mean seriously, anyone who defends data yielded from a tiny wind tunnel with a massive blockage factor is just off in another world.
And yes, I do have the cited book on wind tunnel testing. Five of the 18 chapters are devoted to the corrections needed to gain any useful data! And a small wind tunnel just makes everything worse.
I have comprehensively proved wrong many of your applications of theory to real cars. As I have said, I don't care what you believe, but when you start leading others astray with your poor advice, then I don't think that is right.
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1) for twenty years, the maximum speed limit in the United States of America was 55- MPH.
2) at 55-MPH, the delta-mpg associated with spinning wheels constituted on the order of 0.5%.
3) in 1995, when the federal government repealed the 55 MPH National Speed Limit, and began to allow individual states to relax speed limits, by default, the impact of wheel drag would necessarily increase.
4) also, SAE requirements for 'crosswind-averaged' coefficients of aerodynamic drag, with yaw angles up to 12-degrees, would necessitate room for turntables for yaw, and in turn, necessitate larger test sections, and larger jets, larger fans, more horsepower, etc..
5) the cost of advanced wind tunnels are a legitimate corporate tax write-off, and customers will ultimately foot the bill for the expense, so why wouldn't they ?, especially during Democratic administrations, calling for 52.5-mpg CAFE standards.
6) Aerodynamic drag reduction is the cheapest way to higher fuel economy.
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* You'll remember from Hucho, that Pinifarina, while one of the world's 'smallest' wind tunnels, returned drag coefficients, some of the closest to the center of the 10-tunnel standard deviation.
* If ' the exception proves the rule', then the accuracy of Pinifarina's data must be a caveat to your claim of 'large tunnel supremacy.' That's all I'm saying.
* And as Richard Feymann admonished Cal Tech graduates, Hucho admonishes: ' ... the vehicle aerodynamicist must refer to a large amount of detail resulting from earlier development work.' ( page-1, PREFACE)
This is an example of a perspicacity failure on your part. From the very first page of the book!
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So far, you, yourself, have failed to demonstrate a failure of any material I've shared. ' Read my book' is not a scientific argument.