Want low drag? Don't follow a template.

[JulianEdgar]

Originally Posted by freebeard

If true, then you should be able to address 3), 4) and 5).

Especially 4)....

There's no point - they have nothing to do with the Coanda Effect as applied in car aerodynamics.

Perhaps this is another of those things where this forum has developed their own definitions and understandings?

[aerohead]

Originally Posted by JulianEdgar

There's no point - they have nothing to do with the Coanda Effect as applied in car aerodynamics.

Perhaps this is another of those things where this forum has developed their own definitions and understandings?

It would be another opportunity to dazzle us with your brilliance!

[JulianEdgar]

Originally Posted by aerohead

It would be another opportunity to dazzle us with your brilliance!

I've given you two references.

But what's the point? If they don't agree with you, they're sure to be wrong, aren't they?

[freebeard]

There's no point - they have nothing to do with the Coanda Effect as applied in car aerodynamics.

Galloping goalposts!

Perhaps this is another of those things where this forum has developed their own definitions and understandings?

Speaking for myself, not "the forum", I seek an intuitive understanding of the clutching fingers of air that retard a car's progress. 4) gets extra credit for using 'exoduct'.

[JulianEdgar]

Originally Posted by freebeard

Galloping goalposts!

Speaking for myself, not "the forum", I seek an intuitive understanding of the clutching fingers of air that retard a car's progress. 4) gets extra credit for using 'exoduct'.

I don't think that intuition is a good approach to learning about anything much.

In car aero, the Coanda Effect is primarily used to describe the tendency of a stream of fluid to follow the contours of a convex surface rather than continue moving in a straight line.

It is therefore present on all normal cars.

[freebeard]

Intuition was the name of Buckminster Fuller's sailboat. He seemed favorable toward it.


https://i.pinimg.com/originals/6a/11...d1baee4ae8.jpg

Originally Posted by aerohead

I am familiar with Coanda, and his research, and his airplane based upon his theory, which never made it off the ground.

The way I got the story he was trying to take off and looked behind him and the tail was lit on fire by a hokey afterburner arrangement, because the exhaust was following the contour of the fuselage. It made one hop over a wall instead of crashing into it, so he survived to have his name attached to the discovery. [citation needed]

Originally Posted by your link

The Coanda effect is also used by the so-called ‘bargeboards’, aerodynamic appendages typically sited between the trailing edge of the front wheels and the leading edge of the sidepods (see Figure 7). Bargeboards are used to guide turbulent air from the front wing wake, away from the vital airflow underneath the car. In addition, the lower trailing edge of a bargeboard creates a vortex which travels down the outer lower edge of the sidepod, acting as a surrogate skirt,

I'd call that over-thinking.

Coandă effect - Wikipedia
https://en.wikipedia.org/wiki/Coandă_effect
The Coandă effect (/ ˈ k w ɑː n d ə / or / ˈ k w æ-/) is the tendency of a fluid jet to stay attached to a convex surface. It is named after Romanian inventor Henri Coandă, who described it as "the tendency of a jet of fluid emerging from an orifice to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops."

[JulianEdgar]

Originally Posted by aerohead

1) Best I can ascertain, the only Coanda technology to make it into the contemporary marketplace is Dyson's Coanda Air Curler hair-care product.
Coanda effect requires an auxiliary power source to power a high static pressure air-handler for the nozzle jet.
2) I know of zero production automobiles which employ this technology. Correct me if I'm mistaken.

Mmmm. Yep. Mistaken again - but I am quite certain you won't take the correction. It's just that the textbooks and experts will be wrong again...

[Vekke]

Julian in science opinions should be backed with research papers. You havent shown any facts that give any proof to your claims. However during this thread people have proven you have used the old template which did not match the cars on your video. If you would have used the latest version of the template which is AST-II you would have seen different results. I wrote here in this topic already long time ago that the data of the template is in many topics spreads wide.

If the data is proving the template is the correct way to go if you want low(est) drag and you cannot provide any real evidence to prove otherwise then no wonder if everyone still believes that template is the way to go. No rumor opinions from Dr wolf or any aerodymic mastermind you say will make any difference when all evidence shows otherwise. Only scientific research opinions matter in science.

Due to reason you have not done your basic research correctly you have ended up using the wront template and created wrong assumptions. Like I wrote even my Lupo 2l roofline is done based on that template. Enen the old template is still better than just guessing how to make it. I knew how to make it, ended just using the old template (my mistake, but the roof was chopped when the new template was just launched and I was too eager just to execute). I remember reading of the new template and also assumed that the aerotool would be using the latest template. However assuming something is the worst enemy of knowing, I think you have also said that many times.

I have seen more than enough proof to still believe that using the template really is the best way to go if you want low drag in your vehicle projects. How to use it in the whole design of the vehicle then just requires more knowledge to solve complex issues that are when designing the sides and underside of the vehicles.

If you are honest human being then real apology to Aerohead is in place and you go and correct the errors you say in your video because they clearly are not true.

I am not asking any more evidence from your side as I think you would have given those already if you have any.

[JulianEdgar]

Originally Posted by Vekke

Julian in science opinions should be backed with research papers. You havent shown any facts that give any proof to your claims. However during this thread people have proven you have used the old template which did not match the cars on your video. If you would have used the latest version of the template which is AST-II you would have seen different results. I wrote here in this topic already long time ago that the data of the template is in many topics spreads wide.

If the data is proving the template is the correct way to go if you want low(est) drag and you cannot provide any real evidence to prove otherwise then no wonder if everyone still believes that template is the way to go. No rumor opinions from Dr wolf or any aerodymic mastermind you say will make any difference when all evidence shows otherwise. Only scientific research opinions matter in science.

Due to reason you have not done your basic research correctly you have ended up using the wront template and created wrong assumptions. Like I wrote even my Lupo 2l roofline is done based on that template. Enen the old template is still better than just guessing how to make it. I knew how to make it, ended just using the old template (my mistake, but the roof was chopped when the new template was just launched and I was too eager just to execute). I remember reading of the new template and also assumed that the aerotool would be using the latest template. However assuming something is the worst enemy of knowing, I think you have also said that many times.

I have seen more than enough proof to still believe that using the template really is the best way to go if you want low drag in your vehicle projects. How to use it in the whole design of the vehicle then just requires more knowledge to solve complex issues that are when designing the sides and underside of the vehicles.

If you are honest human being then real apology to Aerohead is in place and you go and correct the errors you say in your video because they clearly are not true.

I am not asking any more evidence from your side as I think you would have given those already if you have any.

You know, anyone reading this would think the template just dominates current aerodynamic textbooks and papers - and not that it is barely mentioned!

If you want scientific research opinions, why don't you go and read the aero textbooks for yourself? Start with the best - Aerodynamics of Road Vehicles, 5th edition, and see how much space they devote to 'optimal shapes' - two pages in 1300.

Find me some SAE engineering papers that talk about how the template - or any other similar shape - was used in the aero development of cars.

Find me a single professional aerodynamicist that uses a template when they develop cars - or even one who subscribes to the notion than any template could be used!

Seriously, you ask for research papers and yet you - and no-one else - can provide even one SAE paper that supports the notion of a template in the way it is is used in this group.

You want research papers? Go and read them. Maybe start with the couple of hundred SAE papers I read when researching my book.

You're in Germany hunting for a job - why don't you go and talk to some professional car aerodynamicists and learn some real information rather than believing rubbish on a web discussion group?

(And it's very funny that when I show in a video how absurd the template is (you know, the one in the tools section of this site, the one that is used here all the time), people then just suggest using another template!)

[aardvarcus]

Originally Posted by JulianEdgar

(And it's very funny that when I show in a video how absurd the template is (you know, the one in the tools section of this site, the one that is used here all the time), people then just suggest using another template!)

Even funnier is that of the six cars being used to disprove the "template", five fit the AST-II diagram perfectly and the other one is streamlined from top view, begging the question why you thought it was appropriate to do a side view overlay on it?

Those professional aerodynamicists might not use the diagram, but boy their cars sure like to land on it...

I don't know why you blame the website for your use of your favorite AST-I diagram. Other people have successfully navigated to the prevalently used diagram. Most people click more than one link on websites to find their desired information.

What would be really really funny would be a remake of the video, same cars and same script, using the AST-II.