Lotus 7 style front cycle wing optimisation

[OliverSedlacek]

Firstly, apologies if this has been covered previously but I'm new here and don't know why may round.
I've got a Caterham 7 and I'm wondering what I can achieve in terms of drag reduction if I make some new front cycle wings. Many seem to try to just go for a minimal wing (to ape the F1 open wheel look), but I suspect that is the worst thing you can do. The questions I'm asking myself are:
1. Where should the front edge of the wing start? Presumably I want to cover most of the front of the tyre.
2. How tight should the clearance be between tyre and wing? A small clearance would reduce frontal area but increase wind shear.
3. What can one do at the rear of the cycle wing? I don't want to have a great long teardrop, not least because steering becomes impossible. Pinning the separation line is presumably 'a good thing'.
4. How far down the tyre sidewall should I go? As far as the rim?

If there are any wind tunnel or CFD studies I'd be interested to read them.

[freebeard]

Pics way bigger than it needs to be.



Six vortexes. You'll never touch the ones at ground level.

Here's proof:



Dirt is carried over the top of the tire before is it scoured out of the tread. You can see the middle vortexes.

For examples done right I'd point to the Aptera


aptera.scratchpad.brandetize.com/wp-content/uploads/2021/06/6.png

The modern style is to wear your clamshell fenders backwards.


https://external-content.duckduckgo....6pid%3DApi&f=1

[aerohead]

CAR and DRIVER did a road test of the Caterham when it debuted on the market.
I believe they reported around Cd 0.65 for the car.
I'm unsure what effect streamlining the front fenders might bring, but Robert Lewellyn's 3-Wheel 'Sylph', Cd 0.11 would probably have the template for fenders you'd want to mimic.
Robert is an aeronautical engineer and his Sylph was tested at CALTECH.
I know we've talked about it here but I can find no link.
The Edison Light Car and Aptera would also be worth a look.
freebeard's already linked to Aptera.

[freebeard]

I like the Aptera example for the parting lines.

[OliverSedlacek]

I love the way the sand gives you a great view of how far round the tyre drags the airflow. Not sure it's an option round here though.

[freebeard]

It's one of my favorite pictures.

The way I see it the {Mirage lake bed] dirt is carried by the tire's tread. It shows where the cycle fender (if required) should start.

[kach22i]

Thumbnail link:
https://www.freeenergyplanet.biz/micro-hydro/rotor.html

Images of other 7's..............
Locost Aerodynamics... or lack thereof
https://www.pinterest.co.uk/pin/454159943671508608/

These look interesting as far as minimalism.
https://www.flowbelow.com/

https://www.nhra.com/news/2012/smarty-pants



https://www.slotforum.com/threads/19...limousin.9036/



https://www.reddit.com/r/formula1/co...hich_raced_in/


A wheel spat fairing all the way around like on aircraft is best, followed by front/top/back (open sides as on Sylph - see below), followed by front/back, followed by back only, followed by front only.

[some_other_dave]

Heh, the use of the word "wing" confused me for a minute. Then I saw "south bucks" for the location and it clicked. "Wings" as in what we 'Muricans call "fenders", not the airfoil-section things that you see on the front and rear of Formula 1 cars.

[freebeard]

You can see how it goes with pants and spats.

[OliverSedlacek]

Thanks for the comments, and I guess this wont be the only time there will be some US-UK language confusion. I'm not trying for the lowest possible drag, which will obviously be spats. I really need to get set up on CFD.