No worries. No one will see it but us…
Your challenge will be finding a good accurate model of the bodywork. Find a person, with a helmet in a seated position isn’t too hard.
Do CFD programs create designs yet for you (like CAD /CAE does for 3d printing scenarios). I used ANSYS at uni and it was a little simple in the application i was using it.
Am I missing something here?
Take pods off… add some lead to off-set weight difference … do some laps
Put pods back on … remove lead … do some laps
repeat a couple times. check data.
Surely this is the least complicated way to get a baseline performance differential (really seeing if there is one at all. There may some side effects from a handling perspective but data is still gonna be pretty informative) before working in a simulated environment?
You can’t beat real world data.
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Im not sure hwat you mean by does CFD create designs. I can import 3d models or create 3D models in autodesk inventor than import it into autodesk CFD to analyze it. Im not sure if it can actually calculate downforce on a complex object, I may need a different program.
Oh yeah no problem. I should of give its correct nomenclature, ‘generative design’. Copied from Wikipedia lol:
“Generative design is an iterative design process that involves a program that will generate a certain number of outputs that meet certain constraints, and a designer that will fine tune the feasible region by selecting specific output or changing input values, ranges and distribution.”
So in CAD/CAE, you contrain your design and the software gives you a design. Thats how you end up with funky designs like this, with the first one being a typical design by an engineer and the revisions as the software takes different runs at it:
So for structural designs, it allows you to design something that meets the need but is much lighter. I didn’t know if CFD had started doing that yet. So tell the software what you want the output to be (low drag for example) but some contraints (like size and ability to handle an impact etc) and it will output the most efficient design automatically.
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ohhh I get what youre saying now. Ive never used AI like that before but I could try. Restricing it and creating constraints may be beyond my ability for something as complicated as a kart fender. I can try to see if its available but Im probably going to end up with something that no longer looks anything like a kart
Which ANSYS software did you use? There are many options in terms of CFD. Not sure which one would be best for calculating drag and downforce. seems a little overkill for what I want
A tall driver with big feat is at less of disadvantage with bodywork that can spike (Conical effect) the air prior to hitting his feet/helmet. ( Cough M7 ) or a Wide Driver is at less of a disadvantage if you can push more of that air around the driver ( Cough Dynamica ) then if it was bodywork that didn’t push air around the driver. On your average 5ft 8inch 140lbs Karter your not going to see the same kind of gains.
What would you define as tall or wide? I was looking at updating my old worn bodywork and had been looking at the Dynamica but your comment now has me wondering if the M7 would actually make more sense for me.
FWIW, I can say that I felt a noticeable difference in the amount of wind hitting my torso with the Dynamica vs my current fairing. Cant compare times however since it was a different kart.
Does anyone have a model of a current bodywork style kart? even better if it includes a driver. Otherwise I’ll have to figure out how to do that photo thing and travel up to NH. I think Im going to use autodesk CFD because I get it free as a student. (normally $9,000!!!)
We are talking 15 years ago, not sure what version of ANSYS we were using.
I imagine you’ll struggle to get a CAD model of the bodywork. It’d be proprietary information they’ve supposedly developed in the windtunnel.
As your student you might be able to convince Parolin to give you the model as part of a project you are doing. They should make you sign an NDA and share your results with them, but they might not.
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Nik,
We don’t have generative design for subsonic incompressible aerodynamics yet. It’s possible for other fluid flow situations but I think it’s a long way away given how complicated the basic equations of incompressible flow are.
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On Jay Leno’s Garage a few years ago, they did a back to back test like this. They had a karter run laps with body work, and without body work to see the difference. Without body work was obviously slower, but I think that was mostly due to the kart not wanting to turn. The driver made comments after the run that in some of the corners, the kart wanted to push when there was no body work.
That’s an amazing idea. I’ll send a few emails out to bodywork suppliers asking for cad files etc and I’ll let you know what happens.
I saw a Crg kart at his garage when I went there last year. Was pretty cool. If you ever get the chance to visit do so. Also saw one of my local teams at the Boston car show.
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I saw this. TV shows are the least reliable source of scientific information I can possibly imagine.
Not sure I’d tar any particular media types with the same brush. Some people would say the same about forums 
There’s good and bad everywhere. Judge each piece of content (or it’s creators/show) on its own merit.
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true, but on the balance of probability… I do recall this feature, and have a memory of thinking “that’s baloney!!”.
Looks like Olli didn’t get that memo (apart from sharing nassau panel) racing his older kart and enigne without full bodywork 
I race without pods to (against older style bodywork) and can’t say I’ve ever anecdotally felt any loss in pace. For all we know the supposedly ‘increased drag’ could mean better braking performance… who knows, i doubt it, I just wanna see the real world data
I am a skeptic till proven otherwise. I would test this myself but in Lockdownville means we’re pretty much out the game for another year
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While I agree that TV shows can take liberties for entertainment, just sharing that what you were asking for was done. (Body work and no body work back to back).
Also, karts can obviously be raced without bodywork since they were raced that way at some point. And now the karts use bodywork, and they could have evolved to need the bodywork to run efficiently. There is always a constant evolution, and adjustments to make karts (or cars) work with what’s been developed for them.
Yeah, that TV show already had a pre-determined answer before the test. I recall watching it ages ago and dismissed it. TV shows aren’t in the habit of wasting money and filming stuff they might not be able to use if they can help it. If I could run the test myself I could but that’s not gonna happen any time soon. Hence why I want one of you guys to do it
Sure the bodywork has evolved, but the data on their efficacy from an aero efficiency performative standpoint is very thin. What I do know is OTK dealers are selling a nassau panels for nearly 200 quid. That’s the only solid data point we have. Sure they look like they must have an effect, but that’s a cognitive bias we should all be weary of.
IF it is the case that they conclusively improve performance then we have a problem on our hands. I can’t stress enough how ludicrous it is to me that a nassau panel is being sold for 180 quid. To me it’s pure waste. Monetarily and environmentally speaking too.
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My $0.02, looking at some old CFD data from:
Go-kart aerodynamic optimization by means of CFD and RBF Mesh Morphing-min.pfd
The evaluation of aerodynamic drag of go-karts by means of coast down test and CFD analysis.pdf
Drag was mainly due to:
The driver (~33%). The nassau panel helps, and wider is better than narrow. These haven’t changed much so I don’t see this data changing much as the remaining drag is then not frontal, but rear, behind the seat since there is nothing there to smooth out the flow creating a large low-pressure area. The driver here is much like the trailer of a semi-truck - such as: Truck Drag Study
The wheels (20-30%), with the rears about twice as much as the front. This again is partially due to drag behind the rear wheels since there is nothing there to smooth the flow out.
Since none of the newer types does anything about these two main rear drag sources, I would doubt that minor changes should not change the results more than a few percent. Of course thinner sidepod plastics weigh less, so that helps bring the weight inward which makes for a better handling kart. Running without plastics would increase drag, but also lower weight if that is not adjusted for, so it may be a toss-up.