The Fastback bloc

[JulianEdgar]

Originally Posted by aerohead

Taycan's pretty close to the template, and the spoiler would be handy at those speeds. Hucho says that simply lofting the rear end of the Porsche up to the template contour would be even better for drag and lift, but he'd also say that the stylist would have the ultimate say in the matter. And probably, thumbs down.

You write absolute rubbish - and your fake attributions are disgusting.

Hucho has never written anything about the Taycan, let alone the statement you attribute to him.

[JulianEdgar]

Originally Posted by aerohead

You've failed to gain anything from our discussion about vortex-induced downwash, and how it gives the illusion of '
attached 'flow.
Put the Tesla Roadster-II under the template and see what they've done for a 250-mph car.

Just what I said Aerohead would do! Tuft testing showing attached flow isn't really showing attached flow if Aerohead doesn't agree with it.

Spare me the mental contortions to attempt to justify the unjustifiable.

[JulianEdgar]

Originally Posted by aerohead

Why is it Cd 0.26 and not Cd 0.22?
Why is Spirit Cd 0.217 as a BEV? And lower if measured at A2. Even lower if measured at Toyota?
It's the positive pressures causing all the trouble on the XE. The TBL cannot tolerate that.

Just the normal mix of Aerohead irrelevancies and misunderstandings.

And, I am starting to realise, quite breathtaking arrogance - Aerohead obviously thinks he knows far more about car aero than Jaguar, Porsche (etc). Amazing.

[JulianEdgar]

Originally Posted by aerohead

Take it up with Hucho. I haven't shared anything that he didn't publish. You're a 'writer' okay. You just haven't mastered reading for comprehension. You should be correcting me scientifically, out of the same book the we share.
Since you don't or won't. what am I to think?
You can't present a logical, linear, coherent argument to defend your belief system while overturning Hucho's ground rules for fluid mechanics.
I suppose you also argue female anatomy with God.
You're a funny fellow. Indeed.

You haven't addressed any of my points - understandable of course when you show such grave misunderstandings of the topic.

So, let me restate them:

First faulty premise: if the shape curves downwards faster than The Template, flow separation will occur.

Second faulty premise: if the shape curves downwards faster than The Template, flow separation will occur and therefore low pressures - and so lift - are due to separation.

Third faulty premise: rear spoilers reduce lift by 'reaching up' to the streamline that would have occurred had 'The Template shape premise' (ie Premise 1) been true.

(To be fair, the third faulty premise is faulty only on cars with attached flow. Where separation occurred at the end of (say) the roof on a sedan of the 1960s, this was a valid idea [just not with The Template as the demarcator] and certainly not with cars of the last 30-odd years.)

[aerohead]

Originally Posted by JulianEdgar

I am pretty amazed that you are now nominating another template for rear add-ons. This is just continuing the problem!

The whole idea of a templated shape for add-ons is flawed - at minimum, flow attachment will depend on the thickness of the boundary layer, which depends on what is happening ahead of the template extension.

There's only one thing having to do with flow attachment on an automobile, and that's existence of a turbulent boundary layer operating in a pressure regime which does not violate the conditions in which the boundary layer can remain attached. It has absolutely nothing to do with boundary layer thickness. If the boundary layer goes, so does the rest of the flow.
The 'template' is a guarantee for a vital boundary layer. It's contour is proven.
After you learn what 'streamlined' means you'll gain an appreciation for what wer'e discussing.
The only problem is your ignorance of fluid mechanics.
Perhaps you should also write books on Michelin-rated restaurants. Certainly, you know more about five-star cuisine than master chefs and the funny language they use in the course of meal preparation and at culinary academies.

[JulianEdgar]

Originally Posted by aerohead

There's only one thing having to do with flow attachment on an automobile, and that's existence of a turbulent boundary layer operating in a pressure regime which does not violate the conditions in which the boundary layer can remain attached. It has absolutely nothing to do with boundary layer thickness. If the boundary layer goes, so does the rest of the flow.
The 'template' is a guarantee for a vital boundary layer. It's contour is proven.
After you learn what 'streamlined' means you'll gain an appreciation for what wer'e discussing.
The only problem is your ignorance of fluid mechanics.
Perhaps you should also write books on Michelin-rated restaurants. Certainly, you know more about five-star cuisine than master chefs and the funny language they use in the course of meal preparation and at culinary academies.

More confusion - and now personal disparagement as well.

Let's just consider this idea that the template will cure all ills. We put it on the back of a car that has a rough underside, where boundary layer conditions have caused separation. Suddenly all will then be well at the back of the car?

The use of The Template as any kind of guide to modifying cars is just simplistic nonsense, as a few seconds of thought, and some viewing of the pics I have posted in this thread, will show.

[aerohead]

Originally Posted by JulianEdgar

I don't know how you get to that - Aerohead has repeatedly stated that his theories are correct in the face of contrary test results.

I emphasise: repeatedly.

Contrary? Or misinterpreted? Your home-brewed tests fail the scientific rigor required of any SAE peer-review and publication.
I've given you my sources. Chapter and verse. Derived in REAL laboratory settings, by career investigators, corroborated by third parties, globally.
Your BA in writing is equivalent to a PhD in mechanical engineering?
You can't tell us anything about Bernoulli, but you'll correct the PhD's who use it to design the aircraft you fly on? Hypocritical? Rude? Disrespectful?
Yogi Berra has said, 'You can see a lot by looking.'
Why don't you crack Hucho's book back open and see if you haven't gone off the rails some where as far as logic and deductive reasoning goes.
When you open your mouth, you stand naked to the world, revealing the impoverishment of your mind.

[JulianEdgar]

Originally Posted by aerohead

Contrary? Or misinterpreted? Your home-brewed tests fail the scientific rigor required of any SAE peer-review and publication.
I've given you my sources. Chapter and verse. Derived in REAL laboratory settings, by career investigators, corroborated by third parties, globally.
Your BA in writing is equivalent to a PhD in mechanical engineering?
You can't tell us anything about Bernoulli, but you'll correct the PhD's who use it to design the aircraft you fly on? Hypocritical? Rude? Disrespectful?
Yogi Berra has said, 'You can see a lot by looking.'
Why don't you crack Hucho's book back open and see if you haven't gone off the rails some where as far as logic and deductive reasoning goes.
When you open your mouth, you stand naked to the world, revealing the impoverishment of your mind.

More personal disparagement.

I guess it must be hard when your pet theories, apparently endorsed and accepted for so long, can be so easily shown to be utterly wrong.

I was particularly fascinated by Aerohead quoting the Hucho diagram on Page 51, with no apparent realisation by Aerohead that the depicted pressures applies only with an imaginary, ideal, viscosity-free fluid...

[aerohead]

Originally Posted by JulianEdgar

Who said that it did?

What tuft testing shows very clearly is whether the flow is separated or attached.

So arguing that cars that have sharper downwards curves than the The Template will have separated flow (as Aerohead constantly states) is demonstrably wrong.

And, as a result of that, most of Aerohead's theories (eg lift, required height of rear spoilers) are also wrong.

Between Hucho, Mair, and Buchheim, you should know that, at no time, and under no circumstance, can a turbulent boundary survive a contour which slopes any steeper than 22-23-degrees.
You're continually deceived by tufts, for scientific reasons spelled out to you nearly a year ago. Maybe you could put on the big-boy pants and get yourself into a laboratory where they have the proper tools to conduct flow visualization and measurement. Your yarn isn't going to cut it.

[JulianEdgar]

Originally Posted by aerohead

Between Hucho, Mair, and Buchheim, you should know that, at no time, and under no circumstance, can a turbulent boundary survive a contour which slopes any steeper than 22-23-degrees.
You're continually deceived by tufts, for scientific reasons spelled out to you nearly a year ago. Maybe you could put on the big-boy pants and get yourself into a laboratory where they have the proper tools to conduct flow visualization and measurement. Your yarn isn't going to cut it.

Yep, tufts show lies when they don't agree with Aerohead. It's not really attached flow, it's imaginary attached flow.

What amazing logical contortions.