Lift

[JulianEdgar]

Originally Posted by aerohead

If you have the color photo from Honda, of the Insight undergoing smoke flow testing in their wind tunnel, you'll be able to discern compromised flow over the hatch.

Get away from the PC and do some testing. You say you have the car - well, test it then.

Then we can compare, for the Insight:

• measured front and rear lift
• pressures above and below the car
• separated and attached flow patterns.

You'll find then that a great deal of what you say is simply wrong.

Turbulence cannot conduct pressure. Even burble-point is problematic. Pressure over the entire hatch area takes on the pressure of the separation line if it exists. The closer the separation is to the suction peak, the lower the pressure over all the roof behind it.

I am sorry, but this is largely meaningless in the context of the Insight. (Is 'burble point' another of your invented terms?)

I own this car. I've never experienced objectionable driving behavior.
A neighbor's father in law, from which I bought the car, obtained 3-Wheeler's Insight boat-tail and 80-mpg HWY is not uncommon for him. And he reports no adverse driving behavior.

Well, all that I can say is that you must have a quite limited experience in driving a variety of cars. I love the Insight, but to suggest that its on-road behaviour in standard form is good is just garbage.

[JulianEdgar]

Originally Posted by aerohead

I've addressed it in #34-permalink below.
Hucho addressed all this in his 2nd-Edition. There's nothing new that's transpired since 1986.

There's your answer - according to Aerohead, cars haven't changed in appearance, airflow patterns, etc, since 1986. That's 34 years.

Coincidentally, I tuft tested my 1986 model notchback car back in 1988. I can state with absolute certainty that it had rear airflow patterns utterly different to any current notchback car.

[freebeard]

Any information derived from tuft testing is extremely problematic.

Scott Adams suggests the word problematic translates as 'I don't have a case'.

[JulianEdgar]

Originally Posted by aerohead

If you'd actually read Hucho's book you'd be stuck with the same conclusions.
Aeronautical engineer Larry Mauro doesn't know anything about automotive aerodynamics, although his friend Peter Brock certainly does.
My college chum Glenn got his Master's degree in aeronautical engineering from NASA, but it doesn't qualify him for automotive aerodynamics.
None of the car companies your associates worked for have generated novel low drag cars. The only reason Tesla gets a pass is because it doesn't have the cooling system and belly mutilations of a conventional ICE vehicle, otherwise, they're no better than a 1989 Opel Calibra.
Other than the popular literature, or what can be gleaned from online, my income precludes me from staying abreast of contemporary professional developments, however, the fundamentals don't change.
In 1986 Hucho thought the future would produce a Cd 0.20 car. In 1987, the Cd 0.19 Impact debuted. Hell of a ride! The future moved fast! I recommend we catch up to the past.

I'll just repeat what I previously wrote:

Unfortunately, Aerohead has built entire theories on faulty and / or outdated premises, and then extrapolated them to the point where a great deal that he writes is completely wrong. (Not everything, but a lot.)

He then denigrates the real experts. Who? Well, he has made adverse comments here on a number of aerodynamicists, including the head of Porsche aero, the head of Jaguar aero, an F1 aerodynamicist, a former Tesla aerodynamcist - and so on.

So he doesn't read current aero literature, and doesn't want to learn from real experts.

That's not a good combination for giving people advice!

And about this:

Other than the popular literature, or what can be gleaned from online, my income precludes me from staying abreast of contemporary professional developments

That's fine: but the trouble is you refuse to learn from people who are keeping up with things!

[JulianEdgar]

Originally Posted by aerohead

I remain steadfast in my rejection of tufts as accurate indicators of flow.

I bet you do! It's a real problem when observed reality doesn't match your theories, isn't it?

[aerohead]

Originally Posted by JulianEdgar

Get away from the PC and do some testing. You say you have the car - well, test it then.

Then we can compare, for the Insight:

• measured front and rear lift
• pressures above and below the car
• separated and attached flow patterns.

You'll find then that a great deal of what you say is simply wrong.



I am sorry, but this is largely meaningless in the context of the Insight. (Is 'burble point' another of your invented terms?)



Well, all that I can say is that you must have a quite limited experience in driving a variety of cars. I love the Insight, but to suggest that its on-road behaviour in standard form is good is just garbage.

*At my age I can't imagine wasting the time on such folly. There are things way more important than this.
* If I'm wrong, then Hucho and all the rest are wrong.
* Ask Bernard what it is. He's the wing guy. He'll know.
* 'Garbage' is a non-quantifiable term. How does one quantify such a subjective 'metric'.? Such language has no place within a scientific discussion.
* Have you ever paused and considered the possibility that you may not be the sharpest knife in the drawer? Some of your brain vomit is incoherent, non-linear, contradictory, and some of the evidence you defend your thesis with only leads us to contrary conclusions. In your own Julian-speak, it's BS, Rubbish, and leads your reader astray.

[aerohead]

Originally Posted by JulianEdgar

I bet you do! It's a real problem when observed reality doesn't match your theories, isn't it?

I've already bought popcorn and a soft drink in anticipation of your defense of the VW New Beetle tufts, in light of Volkswagen's own wind tunnel photographs of flow separation in the very location in which your tufts 'insist' we believe that there's attached flow. Jerry Seinfeld ain't got squat compared to your reality show.

[JulianEdgar]

Originally Posted by aerohead

* Have you ever paused and considered the possibility that you may not be the sharpest knife in the drawer?

Yes.

That's why I rely on real experts to give me feedback, and correct me where I am wrong.

And I have been extraordinarily lucky that they have been happy to spend time and effort in doing that, and massively expanding my understanding.

You see, unlike you, I don't just dismiss what professional, practicing, car aerodynamicists say. I listen very carefully, reflect on their points - and then often go out and trial - on real cars - what they have told me.

It's an approach I recommend.

[skyking]

Originally Posted by aerohead

I've already bought popcorn and a soft drink in anticipation of your defense of the VW New Beetle tufts, in light of Volkswagen's own wind tunnel photographs of flow separation in the very location in which your tufts 'insist' we believe that there's attached flow. Jerry Seinfeld ain't got squat compared to your reality show.

Having 3 of those new beetles, I have accepted the inferior economy when compared to the Golfs or even Jetta sedans. It was about two doors and ultimate headroom. If the tufts show "attached" flow, then they are truly worse than no data in that case.

[JulianEdgar]

Originally Posted by skyking

Having 3 of those new beetles, I have accepted the inferior economy when compared to the Golfs or even Jetta sedans. It was about two doors and ultimate headroom. If the tufts show "attached" flow, then they are truly worse than no data in that case.

You appear to be assuming that 'attached flow' always equals low drag. Not true!

As I have written here before, it means only that the airflow is being guided by the car's surface. No more and no less.