ADDENDUM to Hucho's 2nd- Ed. Subject Index

[aerohead]

'remembered my book finally. The following are additional pages where listed subjects are found in the book ( lower case ).
Subjects found within the book, but not listed ( in brackets ).
* aspect ratio, 503
* Bernoulli's equation, 490, 503, 508
* ( bistable wake ), 145
* body of revolution, 142, 145, 199
* boundary layer, 8, 140, 586
* ( bulbous ), 311, 314
* ( danger ), 22
* displacement thickness, 412
* downwash, 18
* ( dynamic similarity ), 304
* ( effective fineness ratio ), 200, 201, 210
* ( energy crisis ), 37
* ( driving speed ), 9
* ( ergonomics ), 35
* ( extremely low drag ), 29
* fineness ratio, 201, 202, 209, 210
* ( high pressure increase ), 117, 140
* ( high speed ), 30
* ideal body, 28, 45
* ( ideal fluid flow ), 52, 117, 140, 141, 483
* ( ideal front ), 129, 130, 136
* ( individuality ), 45
* induced drag, 117, 118, 119, 122, 123, 145, 146, 147, 148, 149, 150
* ( integration ), 12, 13
* ( inviscid ), 49, 50, 51, 52, 53, 57, 481, 483, 487, 511, 514, 516, 521, 534, 535
* ( Klemperer ), 39
* ( look-alike ), 41, 43
* ( longitudinal vortices ), 145, 239
* low drag configuration, 19, 29, 44
* ( minimum drag ), 30
* ( momentum ), 484
* ( non-viscous exterior flow ), 107
* optimum front end, 130, 131, 132, 133
* ( optimum rear inclination ), 153, 154
* ( overall drag ), 19
* overshoot, 185
* ( perfect fluid ), 487, 488
* ( practical ), 23, 25, 37
* ( pseudo-Jaray ), 18
* ( real flow ), 140, 141, 483, 500, 533, 534
* ( real fluid ), 48
* separation, 16, 32, 33, 49, 117, 123, 124, 140, 240, 241, 242, 244, 247, 248, 251, 252, 281, 282, 307, 309, 481, 500,514, 519, 520, 521, 522, 524, 526, 527, 534, 535
* ( shear layer roll-up ), 518
* slant (slope) angle, 114, 115, 116, 119, 120, 145, 146
* ( state of knowledge ), 45
* ( steep pressure ), 140
* ( steep sloping rear ), 18, 116, 119
* streamlined automobiles, 10, 26, 27
* streamlined bodies, 39, 57
* ( streamlining ), 28, 29
* styling, 6, 7, 16, 17, 26, 27, 29, 45, 142, 175, 186, 187, 188
* ( suction peak ) , 140
* ( theoretical inviscid flow ), 57
* top speed, 38
* ( total drag ), 18
* ( turbulence ), 57, 107, 483, 528, 530, 534, 536
* turbulence level, 309
* ( undisturbed air flow ), 282
* ( uniformity ), 43
* ( vehicle width ), 117
* ( very low drag ), 117
* vortex-induced drag, 18, 64, 116, 117, 123, 151
* ( vortex-induced lift ), 64, 122, 148, 150
* yawing moment, 22

[JulianEdgar]

That all looks very good, but it's probably relevant only if Hucho (2nd edition - 1981 - first English edition 1987) is the one and only car aero reference that's available to you.

I think it is a fantastic book, and it is great that it is available now so cheaply, but as you'd expect, things have moved along a great distance in the last 30-40 years.

So, just as with Scibor-Rylski (another excellent book), you need to read Hucho second edition in the context of its time. That is, it typically covers production cars with high drag values, rough under-floors, notchbacks that look completely different to today, and cars with no ECU-controlled variable aero.

Not to mention that many current production cars' drag coefficients were, back then, the stuff of concept cars or research vehicle one-offs!

I really do think your time could have been better spent measuring some cars' aero behaviour, or inveigling your local library to buy some more recent aero books. (Not sure how that works in the US - here in Australia, each local government area has a free library, and they will often accept suggestions for book purchases. All universities here also allow free access to their libraries - you just walk in and can read to your heart's content.)

[aerohead]

Originally Posted by JulianEdgar

That all looks very good, but it's probably relevant only if Hucho (2nd edition - 1981 - first English edition 1987) is the one and only car aero reference that's available to you.

I think it is a fantastic book, and it is great that it is available now so cheaply, but as you'd expect, things have moved along a great distance in the last 30-40 years.

So, just as with Scibor-Rylski (another excellent book), you need to read Hucho second edition in the context of its time. That is, it typically covers production cars with high drag values, rough under-floors, notchbacks that look completely different to today, and cars with no ECU-controlled variable aero.

Not to mention that many current production cars' drag coefficients were, back then, the stuff of concept cars or research vehicle one-offs!

I really do think your time could have been better spent measuring some cars' aero behaviour, or inveigling your local library to buy some more recent aero books. (Not sure how that works in the US - here in Australia, each local government area has a free library, and they will often accept suggestions for book purchases. All universities here also allow free access to their libraries - you just walk in and can read to your heart's content.)

* By default, it's only germane to Hucho's 2nd-Edition. Nothing else was implied.
* With respect to 'context of its time', the 1975, Ferrari CR 25 had Cd 0.256. That's a 'production' car.
* If you allow for the cooling system drag ( 0.025 ), and drag due to the under floor mutilation of a conventional ICE vehicle ( 0.010 ), there isn't a production vehicle available in 2020 which has a lower drag than the 1975 CR 25.
* The 2023 Lucid Air, @ Cd 0.21 would be the first, if you forget the Cd 0.197 EV1 of 1996.
* Contemporary auto designers are real heroes! ( vomit )
* This is 'CONTEXT' for your assessment of contemporary publications.
PS , I don't care what YOU think. (as far as I can discern, you're incapable of it)

[JulianEdgar]

Originally Posted by aerohead

* By default, it's only germane to Hucho's 2nd-Edition. Nothing else was implied.

Obviously! So my point is that it's of use only to people who want to use an old reference.

* With respect to 'context of its time', the 1975, Ferrari CR 25 had Cd 0.256. That's a 'production' car.

Ah, Aerohead and his habit of altering the meanings of words to suit himself. Attached flow that really isn't, things like that. Now 'production car' is the same as 'one-off concept car'. Amazing.

* If you allow for the cooling system drag ( 0.025 ), and drag due to the under floor mutilation of a conventional ICE vehicle ( 0.010 ), there isn't a production vehicle available in 2020 which has a lower drag than the 1975 CR 25.

* The 2023 Lucid Air, @ Cd 0.21 would be the first, if you forget the Cd 0.197 EV1 of 1996.

So what? You're talking production cars versus a one-off concept car. And even that argument fails because you have left out at least two production cars! What a weird argument.

* Contemporary auto designers are real heroes! ( vomit )

What an odd thing to write.

* This is 'CONTEXT' for your assessment of contemporary publications.
PS , I don't care what YOU think. (as far as I can discern, you're incapable of it)

Returns to personal insults. The veneer is paper-thin isn't it?

[aerohead]

Originally Posted by JulianEdgar

Obviously! So my point is that it's of use only to people who want to use an old reference.



Ah, Aerohead and his habit of altering the meanings of words to suit himself. Attached flow that really isn't, things like that. Now 'production car' is the same as 'one-off concept car'. Amazing.



So what? You're talking production cars versus a one-off concept car. And even that argument fails because you have left out at least two production cars! What a weird argument.



What an odd thing to write.



Returns to personal insults. The veneer is paper-thin isn't it?

1) does anything about contemporary literature overturn the fluid mechanics fundamentals of the last 100-years that you can specifically identify?
2) whether the car was ever mass-produced or not doesn't alter the Cd. Quit steering the narrative onto something not germane to the topic.
3) the same year, 1975, U.S.E.P.A. researchers identified the 'template' roof contour as the only path to low drag. It's no different today.
4) in 1969, R.G.S. White, of MIRA gave us a recipe for Cd 0.245.
5) personal insults will continue, mirroring your precedent.
6) your defense of the Paris dressmakers must originate from an extremely myopic world view. It's extremely dangerous talk.

[JulianEdgar]

Originally Posted by aerohead

* With respect to 'context of its time', the 1975, Ferrari CR 25 had Cd 0.256. That's a 'production' car.

The Ferrari CR25 was never a production car. It was a one-off concept car.

But now Aerohead says this:

Originally Posted by aerohead

2) whether the car was ever mass-produced or not doesn't alter the Cd. Quit steering the narrative onto something not germane to the topic.

There's either some fuzzy thinking going on here, Aerohead has forgotten what he wrote yesterday, or he is doing his usual trick of changing the definitions of words to suit his weird ideas - you decide.

[JulianEdgar]

Originally Posted by aerohead

5) personal insults will continue, mirroring your precedent.
6) your defense of the Paris dressmakers must originate from an extremely myopic world view. It's extremely dangerous talk.

I'll let those points speak for themselves.

[aerohead]

Originally Posted by JulianEdgar

The Ferrari CR25 was never a production car. It was a one-off concept car.

But now Aerohead says this:



There's either some fuzzy thinking going on here, Aerohead has forgotten what he wrote yesterday, or he is doing his usual trick of changing the definitions of words to suit his weird ideas - you decide.

You may recall Hucho's explanation on page 201: ' To what extent basic bodies with high fineness ratios can be used as the starting point for vehicle development depends upon the value placed upon low drag in the future.'
According to Hucho, as of 1986, a Cd 0.09 'production' car was technically feasible.
In August, 1990, Sergio Pininfarina wrote in CAR and DRIVER, ' Basically, with the shapes to which the public is accustomed today, we can achieve values of around ( Cd ) 0.25.'
In his ' Low Speed Wind Tunnel Testing,' Alan Pope wrote, ' Drag is currently secondary to appearance...'
There are dozens of examples where 'the law of the Paris Dressmaker determines the product. Hucho mentions it throughput his book.
We had Cd 0.13 in 1922. As a BEV, 'camera' car, this would be 'off-the-shelf' technology.
Sighard Hoerner personally aero modified an 1935, ( Audi ) DKW Meisterklasse, by throwing away the OEM body, and replacing it with a Jaray Kombination-form, instantly reducing the Cd 0.85, to Cd 0.25. ( in 1935 ).
Aero 'production' cars require only a rearrangement of ink on a product specification sheet.