A book to buy and read

[JulianEdgar]

Originally Posted by freebeard

I can recall the pushback against Thee Holy Template back when there was only one strong voice on the forum (which you missed). I look forward to the day that the two of you can work together.

You always talk about historic push-back against The Template. That's nice, but (apart from me and, more recently, Vman455) there's been no recent pushback at all against the absolute garbage Aerohead constantly spouts.

I know some people who have posted here can see straight through his crap, but (and I respect their choice) they choose to walk away - why bother wasting time trying to counter the rubbish? But I have spent decades trying to communicate good car modification material to people, and to see this misinformation being disseminated in such a wonderful area as car aero frustrates me a lot.

And, when I read much of what he writes, I just shake my head in wonder at the outright gullibility of people. Like, even if you know nothing at all about car aero, shouldn't his conspiracy theories be immediately raising red flags? (But maybe not in America? )

Someone described Ecomodder to me as 'a cult', and I can see the parallels.

[M_a_t_t]

Originally Posted by JulianEdgar

I know some people who have posted here can see straight through his crap, but (and I respect their choice) they choose to walk away - why bother wasting time trying to counter the rubbish?

I believe part of this is that we (myself included) don't have the knowledge to know whats right or wrong and lack the resources (and/or gumption) to confirm. As well as some don't really care about car aero, they just want results. In that regard it doesn't matter if something gets separation on the roof if adding a kammback gets you an extra 5 mpg.

Not commenting on validity/content of anyone's posts, but I find aerohead's post very hard to read due to formatting and sometimes the verbiage. Akin to trying to read a masters degree level chemistry book when you are taking a freshman level chemistry course. You recognize some of it, but can't really understand what the text is saying.

Julian's posts are usually much easier to understand. I can also appreciate that he won't come right out and say what to do. Often only offer a quick summary of relevant resources and offer a personal opinion.

I believe that to be part of the "misinformation" (not commenting on content of posts remember ) as well. Some people (not on ecomodder, everyone everywhere) just want to be told what to do rather than think about it. I find myself looking for that sometimes depending on the topic. For example, when I posted about the stock spoiler on my car in this thread: "Excellent paper on rear spoilers?. No one offered any advice of what to do in this case, but when I took the time to think about it and posted what I thought both provided their opinions and some examples of cars I might use as an example of modifications I could try.

I try to remember that this is an internet forum and as such you can't take what anyone says as 100%. Cross reference, experiment, get results, and share them with everyone. If you don't do testing then you are simply imitating or repeating others. Which isn't a problem if you never claim to know anything more than your single data point and other data points that you've read about. When I am asked or offer information about something I have never actually done I always start the reply with my lack of experience and that it is based only on what I've read elsewhere.

Even college professors profess their knowledge. It's still up to you to confirm and form your own opinion about a subject. Which means even if these guys were your college professors you should still be cross referencing them (with your textbook and other resources) to make sure they are correct. If it is true then there should be an experiment you can do to confirm how the conclusion/theory was formed (depending on equipment availability).

Rant over. One day I was trying to figure out why I found Julian's post easier to read and understand than aerohead's. It's been culminating in the back of my mind for a few days now.

[JulianEdgar]

Originally Posted by M_a_t_t

One day I was trying to figure out why I found Julian's post easier to read and understand than aerohead's. It's been culminating in the back of my mind for a few days now.

(1) When I first started commercially writing (about 37 years ago!) I assumed that the bigger the words I could put in, the better. After all, weren't they great examples of my writing abilities?

(2) When I became a school teacher, I realised that understanding was key - and to use the required words to achieve that.

(3) When I started teaching professional writing, I realised that the clearer I could make the concepts, the better.

(4) When I started writing books, I realised that the simpler the words in which I could express the concepts, the better.

My book chapters - and, I hope, the writing I do here - come in at about Flesch Kincaid 9-10. That is, 9-10 years of schooling.

I haven't run a test on Aerohead's verbiage but I'd guess FK = 13-16. It might just be that Aerohead is a crap writer, but my gut feeling is that he deliberately writes in obscure language.

[freebeard]

I find aerohead's post very hard to read due to formatting and sometimes the verbiage. Akin to trying to read a[n] masters degree level chemistry book alchemical grimoire when you are taking a freshman level chemistry course.

I counted it a personal victory when after my prompting aerohead started putting spaces between sentences.

...Flesch Kincaid 9-10.

The problem is that informed people are filled with doubt, while their opposition has never heard of the Dunning-Kruger effect.

[M_a_t_t]

Originally Posted by freebeard

I counted it a personal victory when after my prompting aerohead started putting spaces between sentences.


The problem is that informed people are filled with doubt, while their opposition has never heard of the Dunning-Kruger effect.

I had a neighbor who wouldn't put spaces between any of the words in a text. "Saved on time" she said. Then you would have to decipher what she was saying.

I can get behind that statement. I was interested in psychology during the class, but not enough to pursue any higher classes.

[freebeard]

Bet she didn't talk that way, amirite?

Space Between Words: The Origins of Silent Reading - Paul ...
https://books.google.com/books/about...d=w3vZaFoaa3EC
The separation of words (and thus silent reading) originated in manuscripts copied by Irish scribes in the seventh and eighth centuries but spread to the European continent only in the late tenth century when scholars first attempted to master a newly recovered corpus of technical, philosophical, and scientific classical texts.

Sentence spacing came later, with the advent of typesetting. The debate on one or two spaces was mooted by CSS proportional line spacing (with justified text).

Even college professors profess their knowledge [red-tinted intersectionalist programming]. It's still up to you to confirm and form your own opinion about a subject.

[freebeard]

www.washingtonpost.com/One space between each sentence, they said. Science just proved them wrong.

This is informative until the end. Then it just gets funny:

Johnson told Lifehacker that she and her co-authors submitted the paper with two spaces after each period — as was proper. And the journal deleted all the    extra spaces anyway.

Note: An earlier version of this story published incorrectly because, seriously, putting two spaces in the headline broke the web code.

[Piotrsko]

One thusly supposes how expensive storage really is.

[aerohead]

Originally Posted by JulianEdgar

I can see you might think that if you've just skimmed stuff. But unfortunately a great deal of what Aerohead writes here - and especially when he gives advice or theorizes - is simply outright wrong.

Whether that's because he hasn't understood the theory or is just mis-applying it, I don't know. Sometimes, he takes accepted (and correct) theory and then just extrapolates it into complete weirdness.

And then we have to add that he hasn't bothered keeping up with aero developments of the last 20-30 years.

The result is that he is grossly in error on many aero topics.

Just off the top off my head here are some of things he constantly gives incorrect advice on:

- attached and separated flow patterns
- pressure distributions on cars
- the relative importance of lift forces
- the lowest drag wheel designs
- how rear spoilers work on current cars
- best angles for rear diffusers
- sharpest rear angles that will retain attached flow
- flow patterns on current notchback cars

Then overlay all that misinformation with some truly weird conspiracy theories about how car makers develop cars, write in a pseudo-sophisticated mumbo jumbo that is often impenetrable, and we have a fascinating situation that has obviously developed over a long time.

Unfortunately, by far the number 1 source of misinformation on aerodynamics on this forum is Aerohead.

I used to think about half of what he wrote was wrong / misleading / irrelevant, but as he has now been nominating references in an attempt to support his misleading statements (and where I have them, I have been checking those references), I now realise it's even higher than that.

I don't like misinformation about car modification being spread: it costs too many people money and time - people who should be benefitting from the best info available, not wrong and/or outdated advice and strange theories.

I haven't bought any SAE Papers for the duration. At $ 30 a pop, that's too rich for my budget. The internet although, has been a source for some contemporary investigations. Like rolling road tunnels and wheel drag.
EcoModder members have been very good about scanning for, and sharing links to online research papers.
* I keep waiting for you to correct my understanding of flow separation. I can't seem to find any counterfactual evidence, only validation.
* The pressure distributions aren't of the same value as axle loading vs static wheel loading, with passengers and luggage onboard, at full GVWR, at 'normal' passenger car velocities.
* As vehicle speeds have increased, so have vehicle mass. Tire technology has kept pace. Aquaplaning risk may not be any different than 30-years go. The popular press doesn't mention it.
* The ' WS12 Aerodynamic Performance' report spoke of 'uncertainty.'
For the rear wheel fairing data, depending on fairing depth, 'wheel stationary' vs ' wheel rotating' demonstrated no discernable drag difference, depending on fairing depth. Alan Pope talked about 'rotating' wheels vs 'stationary ' wheels amounting to a 'few percent' difference in drag. A locomotive example showed a 5.263% delta. General Motors published that the difference was around 5%, was easy to compensate for, and not worth the expense.
* As to rear spoilers, we're not through the discussion yet, so you might hold your opinion.
* Carr and FIAT got identical values for diffusers. If you have some value-added material it would be much appreciated.
* The sharpest rear angles are from Buchheim et al. Cars aren't built like that any more. As to 'curved-roof' rear contours, the 'template' is scientifically close to 'ideal / optimum' ( Hucho uses the two terms interchangeably ).
* The 'template' can be found at the bottom of Figure 2.1, page 61.
* The streamlined body of revolution from which the 'template' is derived is 3rd from the bottom of Figure 2.1. It is the 'shortest' streamline body which respects Mair's 22-degree cut-off threshold for rear slope angle for preventing separation.
* Any shorter and we suffer pressure drag.
* Any longer and we suffer friction drag.
* It is 'optimum.'
* For flow patterns on contemporary notchback cars, the Cd will indicate the amount of separation. Drag is a function of separation. Nothing can be done about skin friction.
* The days I come to town, I experience Sentras, Accents, Rios, Lancers, Civics, etc.. which appear incapable of flow reattachment. Technical drawings compared to the 'template' indicate separation with no reattachment.
* ' The problem of 'streamlining' is to devise shapes such that the boundary layer will not break away and the wake will remain inconsiderable. It is found that to delay the breaking away of the boundary layer the region where the fluid is moving against increasing pressure should curve as gradually as possible, i.e. should have a large radius of curvature. Good streamline shapes should be such that the breaking away point is as near as possible to the trailing edge.' L. M Milne-Thompson, C.B.E., Professor Emeritus,' THEORETICAL AERODYNAMICS, page 22, 4th-Edition, Dover Publications, Inc., N.Y., N.Y..

[aerohead]

Originally Posted by JulianEdgar

Do you actually prefer to have misinformation being spread?! Wasting people's time as they follow incorrect advice? Causing people to develop completely wrong beliefs about the subject of car aero?

I've got this really weird notion that none of those is a great outcome for car modifiers.

So while I can be bothered to continue doing so, I will call out misinformation being posted - from Aerohead or anyone else.

1) 'misinformation' implies 'information' in your possession which will clearly overturn my thesis. Simply walk the reader through your arguments, building your case as you go.
2) My impression is that I provide scientific data, germane to a specific topic, leaving the reader to make their own decisions.
3) I've worked very hard to rid my life of 'beliefs'. If you have some specific reference, I'd appreciate it. I'll correct the mistake.