Why don't vehicles have aerofoils to partially take the weight of the car?

[JulianEdgar]

Originally Posted by AeroMcAeroFace

Adaptive suspension

Yes, I run computer-controlled, height-adjustable suspension on my car.

I think your proposed complexity of car is now out of control for anything but a thought experiment.

I was reading tonight about Buckminster Fuller's 1930s “omni-medium, jet-propelled 4D transport” that he proposed. A car with inflatable collapsible wings that could travel by road, sea or air. Trouble is, to work, it required inventions that hadn't actually yet been made. And still haven't been.

I cannot see how any car of the like you are proposing could run on public roads with current technology and with anything approaching an economic return.

I think it is a really bad idea.

[AeroMcAeroFace]

I never said economic return, it is a theoretical discussion, the gen 1 insight lost honda money, the original veyron lost money, every solar car ever made has lost money. As I wrote in the closing remarks part, it is not commercially viable and may never be. But it is theoretically possible.

It is a discussion board, where we discuss aerodynamics, a lot of that is theoretical.

Complexity, you may have said that photovoltaics, traction control, computer suspension, adaptive cruise control, or lane assist, collision avoidance, or full self driving was too complex initially based on the reward, but they are now mainstream.

It is a bad idea for you to pursue, it wouldn't sell books if it discusses things that don't apply to any readers' cars. But that doesn't invalidate the theoretical possibility which was the discussion here.

[JulianEdgar]

Originally Posted by AeroMcAeroFace

It is a bad idea for you to pursue, it wouldn't sell books if it discusses things that don't apply to any readers' cars. But that doesn't invalidate the theoretical possibility which was the discussion here.

No, I think it is a bad idea for the variety of reasons which have been canvassed in this thread by me and various other posters.

As I said earlier, ideas are easy. Ideas that actually work in the real world are much, much harder.

[AeroMcAeroFace]

Originally Posted by AeroMcAeroFace

Partial lift has been employed by solar cars, but these cars had high front lift and low rear lift in a straight line and low front lift and high rear lift in a cross -wind. The aerodynamic and form priorities of a solar car would not easily align with the aerodynamic and form priorities of a partially lifting body car.

Do I think this concept is useless or flawed? No, of course not, I started this debate to find out why it hadn't been done, because I thought it was possible. Do I think that this concept is practically applicable? Given the right conditions, priorities and restrictions yes I do. Do I think that those will ever arise? No, I don't.

.

Agree to disagree

[JulianEdgar]

Originally Posted by AeroMcAeroFace

Originally Posted by AeroMcAeroFace View Post

Partial lift has been employed by solar cars, but these cars had high front lift and low rear lift in a straight line and low front lift and high rear lift in a cross -wind. The aerodynamic and form priorities of a solar car would not easily align with the aerodynamic and form priorities of a partially lifting body car.

I let that go earlier but now that you are repeating it, it's just further spreading of falsehood.

Where is any evidence that solar cars employed lift? That is, they wanted lift? I've not seen any at all - just the opposite in fact.

Honestly, I must say I thought higher of you than this. Your posts have previously been backed with evidence and thought - now you're spreading outright misinformation.

[AeroMcAeroFace]

It is not misinformation, it is nuanced information that you have generalised or misunderstood such that it is now misinformation.

If you misinterpret something from what is written and then claim that is misinformation then the misinformation is on your part not mine.

Where is any evidence that solar cars employed lift? That is, they wanted lift? I've not seen any at all - just the opposite in fact.

I think this is supporting evidence to what I said earlier, inferring additional meaning to words and then claiming that the evidence does not meet the additional meaning you have added is not correct.

The fact is that for increased efficiency, solar teams have pitched the nose up to increase lift slightly. That is not misinformation, or misrepresentation it is fact, the sources show that.

That doesn't mean it was specifically designed to lift, or that they wanted it to lift significantly, I don't believe I stated anything suggesting otherwise, and the sources listed in the quoted post support my interpretation. However, they employed the front end lift to increase cruise speed.

All my posts are backed with evidence and thought, every post is thought through carefully. However, that doesn't necessarily mean that the evidence supporting my ideas fully proves the concept. It is always support to the theory, not proof and should never be taken as such unless explicitly stated. No additional meaning should be taken from posts and all posts should be taken specifically and without generalisation.

[JulianEdgar]

Originally Posted by AeroMcAeroFace

However, they employed the front end lift to increase cruise speed.

No they didn’t. The pitched up to reduce drag. The lift wasn’t wanted. You are spreading misinformation.

[AeroMcAeroFace]

"However, they employed the front end lift to increase cruise speed".

No they didn’t. The pitched up to reduce drag. The lift wasn’t wanted. You are spreading misinformation.

It doesn't say that the lift wasn't wanted you have added that bit yourself. They pitched the nose up, increasing lift and reducing drag.

As far as you are concerned this whole topic is a bad idea

[Piotrsko]

Stop it both of you.

A nose radius is added to flat bottom wings to increase the apparent angle of attack but it doesn't change the actual angle of attack or a slew of other characteristics thereby increasing relative lift with no additional drag penalty. I don't even fantasize what it is doing in ground effect because there too many variables to even conjure. Once again the extra lift here is a negative by product, but you can reduce overall AOA by perhaps 2-3 degrees to get back to the original COL. I suspect that reduced AOA also negates some induced drag but I believe that would be airfoil and camber line dependent.

The concept here is the racers get it half right, it lowers drag, BUT, they forget about the AOA increase which rotates the nose high to the relative slipstream. They do find out when it picks the wheels off the surface.

One suspects that if they had chosen an airfoil with neutral COP, or a different laminar section and accepted the minimal drag penalty, the racer would have stayed planted.

[j-c-c]

Originally Posted by JulianEdgar

Anyone can come up with ideas - and people very often do. I've had three this morning.

- I wonder if I put cabin outlet vents on the roof whether that would energise the boundary layer and reduce flow separation?

- I wonder if the sky is blue above my house today because someone is holding up a big blue sheet?

- I wonder if I pressurised the frame of my bicycle at say 100 psi whether I could run tubes with paper thin wall thickness?

My classic story of an idea is the probably apocryphal one of WWII. Someone wrote to the UK government saying they had an idea for finding all the German Wolfpack submarines in the Atlantic.

Yes, asked the government, what is your idea?

Oh, said the correspondent, we should just boil the ocean dry.

Ideas are ten a penny - like opinions. Everyone has them. Ideas alone are worthless.

I am also amazed how people have, and I can only describe it as the arrogance, to believe ideas they come up with are worthy of consideration... without their having done even an hour of research or any testing at all. For example, I would never, ever suggest how solar race teams could do better. They are so far ahead of anything I could come up with that it's just not funny. We've had a person in this group suggest that the head of Porsche aerodynamics knows little. He knows so much more than any of us about car aerodynamics that to think otherwise is to be completely deluded.

I am currently (ie this morning) working with a suspension expert as I write a book on the history of car suspension. He knows so much more than I do about suspension that, even if I spent every minute between now and when I die studying suspension, I could never catch up. So yes, I am indeed happy to be guided by experts suggesting ideas. And you can be sure that in every case, they will have plenty of evidence to support the ideas they suggest - otherwise, they wouldn't have suggested them.

Well in as few words as possible it you really think, and apparently have doubled down on your point, "ideas alone are worthless", narrowing your cover in this discussion to include the key word "alone", we disagree strongly.
I'm open to all ideas, from anyone, including yours shared here on this topic, and hope I never, at the least, try to squash them before shared and well understood. My personal life experiences have shown to me, which path is best, for the best outcome.