New (free) tech paper

[Piotrsko]

It's in the handicapped adaptive section along with big fonts, inverse colors, bold text and adaptive mouse settings. About 4 menus deep in settings.

Just set your font color to say..... black (default) would be good enough.

[orange4boy]

Originally Posted by JulianEdgar

I don't want to overly labour the point,

*Overly labours the point*

THE POWER OF PEDANTRY COMPELS YOU!!1!

And I should know...


A word about the models directly from the creators of the DrivAer Models:

A lot of the investigations in automotive aerodynamics are still based on strongly simplified generic bodies such as the Ahmed Body or the SAE body. A different approach is the direct investigation of production vehicles. Especially transient investigations often use generic car bodies. This is due to the fact that an unsteady investigation of an actual production car has so far not been feasible without enormous computational and experimental effort.

Additionally simple car models can help to understand the fundamental flow phenomena and to gain basic insights.

However, as their shapes are too different from actual car geometries these results will not be fully transferable to the development of production vehicles. This is especially true where complex body surfaces are involved, such as the A-pillars, the highly curved rear end or the wheelhouse region.

Actual optimization is therefore often done on real production cars.

Scientifically verifiable results from doing this as amateurs on our cars, is extremely difficult by the words of the experts themselves:

...due to the fact that an unsteady investigation of an actual production car has so far not been feasible without enormous computational and experimental effort.

I'm not saying it isn't fun or that you shouldn't try (god knows I love to do this kind of thing) but there it is. The struggle is real.

I do care about being through and fact based despite what some people make up out of inviscid air but, my favourite way, IMHO, to measure if results are positive: Am I enjoying myself? The rest is gravy.

[freebeard]

I'm not saying it isn't fun or that you shouldn't try (god knows I love to do this kind of thing) but there it is. The struggle is real.

Never give up. Never surrender.

To your point: Free and Open Source software evolves faster than proprietary software. You can see it in the contention between proprietary software *cough*SmartmaticDominion*cough* and the spooks, who've gone open source. Richard M. Stallman is right.

What it means to us here is that CFD for the masses is becoming attainable. My learning curve is to get Blender running on a Raspberry Pi 4b. It's hard to break away from the Apple ecosystem, the Pi doesn't even have a system clock.

Open VDB is the key, it's in there — it's just about my pay motivation level.

Also, Adversarial Generative AI: The power of big numbers compels you.

[orange4boy]

Do you mean that we will be able to use the limited tools and technology at our disposal to apply aerodynamic principals to create, if you will, a “template”, to guide the shapes with which we may modify our vehicles?

NEVAH!!!

It all has to come directly from blood, sweat and tears.

[freebeard]

Do you mean that we will be able to use the limited tools and technology at our disposal to apply aerodynamic principals to create, if you will, a “template”, to guide the shapes with which we may modify our vehicles?

I know what you're getting at, but as Scott Adams explains, processes are superior to goals.

[JulianEdgar]

Originally Posted by orange4boy

*Overly labours the point*

THE POWER OF PEDANTRY COMPELS YOU!!1!

And I should know...


A word about the models directly from the creators of the DrivAer Models:



Scientifically verifiable results from doing this as amateurs on our cars, is extremely difficult by the words of the experts themselves:

...due to the fact that an unsteady investigation of an actual production car has so far not been feasible without enormous computational and experimental effort.

I'm not saying it isn't fun or that you shouldn't try (god knows I love to do this kind of thing) but there it is. The struggle is real.

I do care about being through and fact based despite what some people make up out of inviscid air but, my favourite way, IMHO, to measure if results are positive: Am I enjoying myself? The rest is gravy.

I am not sure what point you are trying to make.

Of course airflow behaviour - especially unsteady flow behaviour - around real cars is complex, and the DrivAer model results cannot be fully transferred to the development of production cars.

Who said otherwise?

I've already described in https://ecomodder.com/forum/showthre...tml#post639209 why this paper is relevant to people modifying their cars.

[JulianEdgar]

Originally Posted by orange4boy

Do you mean that we will be able to use the limited tools and technology at our disposal to apply aerodynamic principals to create, if you will, a “template”, to guide the shapes with which we may modify our vehicles?

NEVAH!!!

It all has to come directly from blood, sweat and tears.

The template has often been used here to do the following:

- Show where there is separated and attached flow on existing cars
- Guide the shape of rear extensions
- Show how rear spoilers on sedans should be positioned and shaped
- Allow the assessment of the ‘aerodynamic purity’ of cars

None of these uses can be justified. The template is simply one of at least five different low drag shapes that has been published over the years. No more and no less that that.

[orange4boy]

Originally Posted by JulianEdgar

I am not sure what point you are trying to make.

That’s too bad. I thought some context for the models from the experts would help improve understanding of aerodynamics.

Of course airflow behaviour - especially unsteady flow behaviour - around real cars is complex, and the DrivAer model results cannot be fully transferred to the development of production cars.

Who said otherwise?

I don’t know. Did someone?

I've already described in https://ecomodder.com/forum/showthre...tml#post639209 why this paper is relevant to people modifying their cars.

Should I run my posts by you first in future to avoid posting things you don’t approve of? Just to be sure?

[Joggernot]

Originally Posted by Piotrsko

It's in the handicapped adaptive section along with big fonts, inverse colors, bold text and adaptive mouse settings. About 4 menus deep in settings.

Just set your font color to say..... black (default) would be good enough.

Found "high contrast" and this is great! Thanks! Also noticed the extra paragraph...

[Vman455]

Now, come on--you quoted this:

However, as their shapes are too different from actual car geometries these results will not be fully transferable to the development of production vehicles. This is especially true where complex body surfaces are involved, such as the A-pillars, the highly curved rear end or the wheelhouse region.

Actual optimization is therefore often done on real production cars.

And then you reached this conclusion:

Originally Posted by orange4boy

Do you mean that we will be able to use the limited tools and technology at our disposal to apply aerodynamic principals to create, if you will, a “template”, to guide the shapes with which we may modify our vehicles?

But the first quote is a caution against using simple bodies to predict flow over a real car because the flow around them is too complex to predict with something like a template. For example, just because a researcher tested a cylindrical body and found that it had lowest drag with a 22-degree taper doesn't mean that a 22-degree taper will give lowest drag on any car.

(Also, the "context from the experts" you posted refers to the Ahmed body and SAE body, not the DrivAer models. It isn't clear in your subsequent posts that you understood that).