Want low drag? Don't follow a template.

[JulianEdgar]

Originally Posted by ME_Andy

Julian, please take a deep breath and DO NOT reply to my post.

We are lucky to have a template from (as I understand it) a retired professor. It's been useful in many cases. I'm sure it's not perfect for all cases but it's the best tool contributed so far.

I would welcome some input from somebody else about evidence or scientific basis behind the template.

Edit: here's the background for the template. https://ecomodder.com/forum/showthre...rt-c-9287.html

Now that disagreement has been expressed I hope we can move on.

Um, you didn’t address even one of my specific criticisms of how the template is used here!

[ME_Andy]

I would like you to realize that your opinion has been expressed. The personal attacks should stop. Find something else to talk about. Is that unreasonable?

[JulianEdgar]

Originally Posted by ME_Andy

Quote:
I placed Sunraycer under the template,it was a perfect match.Bill Watson's airship "White-Dwarf" of 1984 is about 2.57:1 ratio. Watson worked with Burt Hibbs,aerodynamacist for Sunraycer. Both of AeroVironment. This shape seems to end up on some of the most efficient vehicles known in the world,I believe it to be a shoe -in for aero-modding.Those with more advanced aerodynamic toolbags will will no doubt venture out into some of the more exotic shapes,but for amateurs,I believe this form can serve us well.

Sure. Now apply it to a range of other solar cars and see that there’s no match whatsoever!

The debate has never been whether the template is a low drag shape. It’s one of at least five in the literature - all with quite different shapes.

[JulianEdgar]

Originally Posted by ME_Andy

I would like you to realize that your opinion has been expressed. The personal attacks should stop. Find something else to talk about. Is that unreasonable?

What personal attacks?

I am criticising the spreading of misinformation that is leading people astray. Or would you seriously rather that misinformation keeps being spread without being challenged?

Why don’t you address the specific criticisms I have of the template approach? I listed them above.

[ME_Andy]

Originally Posted by JulianEdgar

What personal attacks?

This is a personal attack:

I see Aerohead, completely undaunted, is back to spreading his misconceptions about his beloved template

Please move on.

[JulianEdgar]

Originally Posted by ME_Andy

This is a personal attack:


Please move on.

It’s the literal truth!

So just confirm for me, you really would rather that misinformation from an individual goes unchallenged? Really?

If you think the template, as used here, is great, why not address my specific criticisms of it?

[ME_Andy]

OK, I'll watch the video.

0:23s : "apparently ideal shape" -- I've never seen anybody here claim that. The original description doesn't claim that.

2:10 : you're right, the template doesn't predict where the flow detaches to a high degree of accuracy. It's maybe 20cm off or so. Big whoop. Nobody claimed the template was perfect, it's an approximation. The original description even says, it should be useful for amateurs.

2:53 : "there's a small separation bubble at the rear of the window". Big whoop. Probably caused by the antenna.

4:41 "testing beats following every template" : yep, agree. If you have time to do so

7:54 The Sagitta and the Taycan look really close to the template to me. Not perfect.

In summary, the template isn't perfect. OK, great. What are we fighting about here?

[JulianEdgar]

Originally Posted by ME_Andy

OK, I'll watch the video.

0:23s : "apparently ideal shape" -- I've never seen anybody here claim that. The original description doesn't claim that.

2:10 : you're right, the template doesn't predict where the flow detaches to a high degree of accuracy. It's maybe 20cm off or so. Big whoop. Nobody claimed the template was perfect, it's an approximation. The original description even says, it should be useful for amateurs.

2:53 : "there's a small separation bubble at the rear of the window". Big whoop. Probably caused by the antenna.

4:41 "testing beats following every template" : yep, agree. If you have time to do so

7:54 The Sagitta and the Taycan look really close to the template to me. Not perfect.

In summary, the template isn't perfect. OK, great. What are we fighting about here?

Here are my criticisms of how the template is used here:

It is claimed to allow you to:

- 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

All these purported uses are simply rubbish!

[freebeard]

I agreed with you at permalink #18.




[crickets]

I think your aggrieved 'come at me bro' attitude is tiring. But.... The forum is pretty much dead except for this 'controversy' and The Lounge, so....

[ME_Andy]

I guess we have very different opinions on the meaning of "rubbish" and "approximation".

I don't mean to be a dick online. Have a good night (/day in Australia).