1268 replies to this topic

[Doctor Ed]

Oh, I've got a few ideas how to make things better... Just wanted to post some baseline pics. I've got an image host set up on another forum, but the way the forum prefs are set up here, it won't allow embedding/linking of that image type... *shrugs* ... I'm not going to setup a new photobucket account just for a few forum posts. I've got my own web hosting. I might set up a new folder and ftp stuff. PITA either way

[techieboy]

I've got an image host set up on another forum, but the way the forum prefs are set up here, it won't allow embedding/linking of that image type... *shrugs* ... I'm not going to setup a new photobucket account just for a few forum posts.

 

Then you're posting some weird link as the site supports all usual image types, otherwise there'd be no images here whatsoever.

[Doctor Ed]

 

I've got an image host set up on another forum, but the way the forum prefs are set up here, it won't allow embedding/linking of that image type... *shrugs* ... I'm not going to setup a new photobucket account just for a few forum posts.

 

Then you're posting some weird link as the site supports all usual image types, otherwise there'd be no images here whatsoever.

the irony of your rolling eyes lies the fact that these forums are riddled with dead images

 

yes, i was trying to link something other than a gif or jpeg. not terribly unusual for forums though.

[Doctor Ed]

so... just for you guys, perhaps someone will find its useful   

 

part 1 - plain jane, flows like a brick

 

 

 

 

 

[Doctor Ed]

part 2 - big ass diffuser + 2 element wing

(diffuser is cut about 80mm up into the rear bumper, lower doesnt really seem to do much)

 

of note is how the wing and diffuser work together, i was mostly looking at the diffuser function here. wing function is probably not brilliant due to the crappy zone of air over the engine bay, but its effect on pumping the diffuser is quite good.

 

 

 

 

 

 

[Doctor Ed]

and part 3 - same diffuser, just run without the wing. no surprise really, diffuser reduces drag from the brick shape butt-zone, but from a downforce point of view is prett much sitting on its hands without the wing

 

 

 

[Doctor Ed]

and finally... how badly can you flow a wing? about this bad! coupe back, massive wing, something something....

 

[Nev]

If it is of any help, I did some experimentation with lowering the front of the car down, once the nose is 7 CM above the tarmac (and in my case a big wing above the roof level) I got fantastic and strong down force on the front at speeds of 90 leptons+. Once I raised the front up to about 11 CM that downforce was more or less gone. I now have the front clam around 9 CM from the tarmac and have some meaningful frontal down force from around 110 leptons.

[stu8v]

Cool 👍

[Aerodynamic]

What have you done to make it flow bad? Or how do you  mean flow bad?

 

Would you like to make a imulation with that big diffuser and a low small rear wing?

 

Br, Per

and finally... how badly can you flow a wing? about this bad! coupe back, massive wing, something something....

 

 

[Doctor Ed]

I didn't do anything per se, rather the flow over the rear wing is simply a byproduct of the dead zone above the engine cover. ill run a smaller wing for you sure, but it's not going to look good. Somewhere in the direction towards the 'no-wing' pics above. On the other hand, I tried a bigger, taller (and wider element) wing this morning.it works well. Not very unexpected. What I want to do is model a coupe back quickly and see what that does to that awful rear flow

[Aerodynamic]

I like this very much nice work.  what if you make a longer roll bar cover, mini coupe back? It´s much simpler to do and could maybe give same effect?

Or vortex generators on the rollbar cover?

 

Br,Per

 

[Doctor Ed]

Vortex generators help flow stay attached... to a surface. There is no surface on the standard rear clam, ie nothing to stay attached to. Vortex generators will do SFA. A longer roll bar cover (mini coupe back) would help somewhat, bringing the flow down a bit. A proper coupe back would be better.

[Exmantaa]

Ah, now I understand your text with that pic better; "and finally... how badly can you flow a wing? about this bad! coupe back, massive wing, something something...."

The coupe back, massive wing, somethin are your options to make the wing flow betten than on a standard body.

 

Nice work. Did you ever look to the work of Winstar on here? He did some flow modelling on diffusers

[Doctor Ed]

^^^ exactly. sorry, just jotting rather than writing properly

 

and soooo... on that point. a basic coupe back. is already 11ty times better than the std rear clam...

 

[Mangham54]

Does your model include the airflow out of the engine cover?

[Doctor Ed]

nope, its not going to change a whole lot

[Nev]

On the other hand, I tried a bigger, taller (and wider element) wing this morning.it works well. Not very unexpected.

 

Good to see some positive feedback on my own greatly maligned "big + tall wing"

 

Keep plugging, always interesting to see what you post up.  

Edited by Nev, 17 January 2016 - 09:35 PM.

[Nev]

Does your model include the airflow out of the engine cover?

 

Flow in/out of the engine cover is virtually nill. People really need to understand/believe this basic fact as the whole area is stalled apart from the last 30 CM near the boot spolier.

Edited by Nev, 17 January 2016 - 09:38 PM.

[Mangham54]

I thought Winstar had concluded that due to the air going through the grill, radiator(s) and bonnet vents, it changed the velocity of air over the windscreen which had a net result of shortening the stall above the rear grill. Plus the small amount of air that separates under the rear tray (where the tray is shaped around the wishbones) in addition to the airflow through the engine bay also slowed the ground effect and helped further reduce the stall behind the car. However I am very likely to be wrong, as this stuff is well outside my knowledge or comfort zone.