h a l f b a k e r y
Is it soup yet?
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
or get an account
In high speed auto racing where speeds are into the triple
digits, the car wants to slide to the outside of a curve or
turn. Centrifugal force. This friction results in tire wear.
On the underside of the body is a large flat funnel that pivots
such that the rear portion can swing as the car
the straight sections of the track the funnel remains
amidships, gathering air from the front of the car and venting
it straight back. In, say, a fast left turn the aft portion of the
funnel slides to the right, exhausting the collected air to the
right to counter centrifugal force and help push the car back
Shark Fins. Passive Aero Version of This
[bs0u0155, Feb 17 2021]
[hippo, Feb 17 2021]
The Nature of Technology: What it Is and How it Evolves, by W. Brian Arthur
Relevant general reading for [bs0u0155]'s rant [pocmloc, Feb 20 2021]
||The vectored air has to not mess up the all the good laminar flow of body and aerofoil work, that give the car down force.
||Isn't the funnel going to be large drag component, trying to deflect air left or right inside the tube? I have often wondered if an opened suicide door or trying to push open a normal door would help cornering.
||In corners where there are cars 3 wide on a track that isn't
much bigger and frequently make a little contact, opening a
door is probably not the best idea. Maybe roughen up the
inside fender air flow with a slight air tripper edge like they
do with the one along the top that keeps them from going
||So, you're vectoring air with a movable aerodynamic
device to produce a net force to counteract the
centrifugal force/impart a component of the centripetal
force required to make the turn. Well, you could make it
work. You'd be better off doing it on the top, high
pressure, side of the car. There, you have more room to
work with and you're not dealing with a complex floor-
road interface which is tricky at the best of times, even
before you add in the finicky nature of the low pressure
side of an aerofoil.
||The thing to consider is, racing is nothing to do with
making fast cars. It's an intersection of the legal &
engineering professions, it's the rules and getting around
them that counts. What you've thought of here, is a
moveable aerodynamic device, they're against the rules in
almost every form of racing, why? Well, they're a really
good way of making a car go faster.
||All the good ways of making a car go faster have been
banned. What we're left with is WORSE ways of making
cars go faster... then for some reason, those ways make it
into road cars, largely for marketing reasons, and they
make road cars worse, or at least over complex and mal-
adapted to their actual role.
||Let's have an example. Say the '94 F1 Ferrari V12. 3.5l
displacement and a fairly astonishing 800+ BHP at an even
more astonishing 16,000+ rpm. So that's 12 pistons
thrashing around at enormous accelerations with 4
overhead camshafts and lots of complex electronics to
keep it from exploding. The forces generated in an engine
like that require very expensive materials and super fine
tolerances, no cold starts here. Not to mention, it's junk
at the end of the race. Is that actually a good engine? No.
It's the most powerful engine they could make that
satisfies the completely arbitrary 3.5l displacement rule.
You can build a better 800 BHP engine in a lot of ways,
but a good example is a NASCAR V8. They're about the
same power, but half the revs, 2/3 the pistons, 1/2 the
valves & 1/4 the camshafts. They can be made the same
or better weight, and into a smaller package. They'll last
10x longer for probably 1/20th the cost and USE LESS
FUEL DOING IT, mainly because they're not wasting all the
extra energy needlessly accelerating pistons. So what
lessons are taken from this and used on road cars? Small
displacement, high revving 4+ valves/cylinder overhead
cam engines that now, they strap turbines to... because
turbines are the answer to low-cost robust consumer
products. Why's that happening? Because politicians saw
the racing rules and liked the general thrust. Cars all over
Europe are taxed on displacement, not efficiency. They
should have just taxed fuel and walked away, engineers
would have been instructed to make efficient engines and
that's what we would have got. Instead, they're told what
to do, and HOW to do it by people who do not understand
the subject. Consequently, the turbo on a 3 cylinder 1.6l
fart box will be junk by 98,000 miles and a big block
Chevy will be considering a rebuild at 2x that. Racing
ruins everything and here endeth my rant.
||[bs0u0155]; preach, brother! Although the shift to electric
everything is solving a lot of these issues. Much simpler
system = fewer things that can be adjusted.
||//the shift to electric everything is solving a lot of these
issues.// And introducing what nightmares? What bugs me
the most, is that the battery in my laptop is noticeably
(and you can objectively check with things like
HWmonitor) worse than when I got it ~12 months ago.
From experience with all the other Li Ion powered
devices I own, I know this trend would continue. I'd be
properly ticked off if I had to buy a new car after 4 years
because it can no longer make my commute in cold
weather. Worse, it's degrading when you're not even using
it, so there's not much relationship between battery
health and use. Battery replacements are still
staggeringly expensive, and I think the only way Tesla is
getting figures of ~5% after a year is because they're
fudging the new performance down slightly.
||Maybe I'm becoming an old curmudgeon, but I think
electric windows was a step too far. At the moment, I
want a bench seat, a V8 and big clunky mechanical 4wd.
If I wanted more sophistication, I'll take the technology
that simplifies things: coil-on-plug shrinks the high
voltage system down. I've seen aftermarket
dashboard/gauge clusters for motorbikes that, because of
the advances in power electronics, mean the components
can be controlled directly.. ditch the whole relay box. I'd
also quite like an electric oil pump, would be nice to get
the oil moving about before the engine parts start
||[bs0u0155] I am intrigued by your ideas and would like to subscribe to your newsletter.
||[bs0u0155] I can see the appeal, but with that attitude, humanity won't break the light speed barrier. If my idea about complexity is right, even the blind paths are needed.
||// I am intrigued by your ideas and would like to
subscribe to your newsletter.//
||It's just Peter Griffin's "You know what really grinds my
gears" with absurd levels of research.
||//but with that attitude, humanity won't break the light
||Carl Sagan used to drive around in a Corvair. Einstein
seemed to do just fine even though he was forced to
teach by making crude markings with a bit of white rock.
Humanity doesn't discard old or even ancient technology,
there's probably a million people poking something with a
stick right now. We generally add to technology when we
develop new and interesting problems. But, the human
impulse to innovate can be misdirected into futile cycles.
||Go & look at HP's website, specifically the driver
download section, there's 1000's, maybe 10's of 1000's of
printer models, yet our 2018 HP monochrome laser is just
as crap as the 2002 HP monochrome printer... it's not
actual innovation, its just working backwards from model
number iteration, marketing and the need to drive
||It's possible to essentially perfect a product, and just
leave it there, no further innovation necessary, maybe a
10 year review to see if any minor tweaks are needed.
||The car, for all it's complexity, is just about there. Need a
pickup truck? Well, all the innovation essentially took
place between 1930-1955, then the designs were
practically frozen for 30 years. They didn't need to
unfreeze it, it was rule changes that forced it. True, a
refresh in about 1993, (ABS, fuel injection) and 2016 (LED
glovebox light) would have been welcome changes, but 5
iterations of woefully immature fuel injection and
infotainment systems that are obsolete when fitted were
a waste of everyone's time.
||The Kitchen Aid mixer had it's 50th anniversary in 1960!
They flirted with a slightly different design in the 50's
then went back to the 30's design. That's the spirit chaps.
||//even the blind paths are needed.//
||Blind paths I'm fine with. How do you know it's a dead end
until you get there? Futile cycles are what annoy me.
Even my world of research, grant bodies have indicated
they want MORE innovative "Moon Shots" in grant
proposals, so we're not going to confirm anything anymore
then? The incentives are now more skewed toward
fraud/ignorance because that's what happens when
pushed to take more risks and not accepting failure.
||I'm thinking of emailing Kitchen Aid to ask them for a
printer. Cast body, chrome trim, 1000 oversized fasteners,
700W motor, 2000 page capacity and a pasta attachment.
||You are right, people are subtly persuaded into futile company cycles for the overall 'keep the wheel turning' system. How does humanity change? The economy's pressure is on all companies. There's no one pinion point for a tire burning hand brake one-eighty. There's just an increasing pressure to pay an ever increasing bill for more and more people.
||With that said, any action has thousands of facets. Who's to say that in the 674th* of the futile cycle of the dumbest product on the planet, a mistake is made that makes fertile ground to true change. Isn't that how evolution works?
||* Not a prophetic number just thought generated. Or is it?
||As a guy who took several classes in hybrid cars and
batteries for them, I can tell you that the batteries
are sized for the expected life of the car, and the
performance shouldn't suffer much at all. They're
oversized and plan for a performance target at end
of life. They're restricted from using that full
capacity so they don't load-cycle themselves and
burn out faster.
||Turbos are added as a good way to handle hotter-
burning engines and meet fuel economy targets.
Politicians don't care about the engineering details.
||Engines are so complex by the requirements that
few bother to rebuild them.
||In a few years we'll all be riding around in self-driving
buses and cars we don't own anyway.
||^ You had a private car, luxury, we hung from people hanging from the sides of the self driving, electric celled trams, in the middle of winter.
||You managed to hang on! We considered ourselves lucky if we were able to crawl low enough that the vehicles didn't hit us as they drove by over our backs.
||We at Camp Teacup were expecting (hoping for) an idea involving race cars modified for use as vent(ilators) in the local ICU. We are jailbreaking CPAP to make BiPAP; not enough oxygen cannulae or tanks. Definitely too few ventilators. Plus, flashy cars would add flair and a certain je ne sais quoi ambience; death by 'racecar' more glamorous than starved for oxygen on a regular vent.
||So, you have added a substantial drag component to the
underside, low-pressure of a wheeled aerofoil?
||Could be something which auto-engaged if the car senses catastrophic loss of traction.. but from what I've seen you'd want that air-scoop on the outside of the curve to counter rotation. If it's on the inside... you'd better have turned far before you get to the corner and be drifting around it.
Which is cool, but not at F1 speeds.
||I'd later* thought of an interior Y-channel, perhaps
ducting within the nice, flat aerodynamic underside of
the chassis, and a flappy valve to select which of the Y
legs the collected air would flow out of. During a hard
left turn the valve would close off the left exit ducting
and open the right portion, exhausting the collected air.
And if the ducting were narrowed approaching the exit
would the exiting air speed increase?
||*after my engineering sins were pointed out.
||Ah, the power and cost that comes from a wall. yes, the air will go faster but it costs. The wall has to be bolted to something to hold it's ground.
||Ultimately, the last thing you want to do is mess with the air/ down force under the car. A lot of race cars have been banned for being to good at down force (Brabham BT46B). Dirt Sprint cars vector air sideways.
||//I can tell you that the batteries are sized for the
expected life of the car, and the performance shouldn't
suffer much at all. They're oversized and plan for a
performance target at end of life.//
||So they are fudging performance at the start to mitigate
the unavoidable degradation. What is the expected life of
the car? The last car I bought was 20 years old when I
bought it (mx5) and is still going strong now, in fact it's
value is rising. The next car I plan on buying is likely at
least 20 years old. None of this will be possible with
electric cars, and it must mean there are plenty of gen 1
Prius/Priuses/Prii?* driving around with the battery doing
little more than slowing the car down.
||//In a few years we'll all be riding around in self-driving
buses and cars we don't own anyway.//
||What a glorious utopia. We'll be moving to the
subscription model of everything, and if the car is driving
itself, you'll have more time to watch ads!
||//the last thing you want to do is mess with the air/
down force under the car. A lot of race cars have been
||The last thing you want to do is mess with the air under
the car MID CORNER. This is one of the better arguments
for banning ground effects. By creating a partial vacuum
between the car and the road you're very susceptible to
suddenly braking the seal, by, for example mounting a
curb mid corner. This means you suddenly loose
downforce and you no longer have the grip to maintain
the corner speed you're already doing and consequently
fly off the track to your death.
*Toyota have a plural problem, Lexus too.
||A thought: you'd probably do better to just tilt the spoilers
in the useful direction. Might need clever timing between
the front & back to get rotation of the vehicle as well as the
radial force for cornering.
||Fwiw, my experience had been as follows:
||When you buy a Prius, the Li battery life is rated at ten years, so
you're forewarned you'll be needing a new one at about that
time, and then there's a dashboard prompt at the point when the
battery has stopped being useful. Now, I made no attempt to
track the maximum capacity in kWh over time, but one thing
that is very easy to track in a Prius is fuel economy. If you allow
that fuel economy is a reasonable proxy for battery
effectiveness, then the battery in my Prius functioned virtually
unimpaired for eleven years before raising its hand to say
"please replace me", and then I had the pleasant surprise that
the replacement cost only about half what I had been led to
expect when I bought the car.
||Of course, YMMV in a very literal sense.