frontal area vs cd

[Vman455]

Originally Posted by jamesqf

Don't know who uses that definition, but it seems a misuse of language at best, since the area would be identical to everything you can see from the back.

What? That's the definition of "frontal area" everyone uses here.

http://ecomodder.com/forum/showthrea...ement-462.html

http://ecomodder.com/forum/showthrea...etro-2439.html

http://ecomodder.com/forum/showthrea...hod-11690.html

"Frontal" because cars normally move forward through the air, so the high pressure is at the front....

[freebeard]

Xist -- The picture was from SEMA, probably 2013. Titled 'sema cool 11 470 1108', from some car blog or another.

It was squirreled away in one of my albums. There's other stuff there in case I find some need or use for it.

[kach22i]

Lowering frontal area.

1. The Chop
http://ecomodder.com/forum/showthrea...etro-4892.html


2. The Tandem
Modified Metro XFi: throwing convention to the wind - MetroMPG.com



Lower Cd

1. The Rear Boat Tail
Aerodynamic tail makes Geo Metro even cooler | Hackaday


Subcompact Culture - The small car blog: Behold: The Boat tail Metro

[arklan]

so the reason i ask, i was thinking of whether or not i should get a prius roller or maybe a daewoo matiz roller to transfer my electric goodies in to
the blue turds gearbox uses oil like it was petrol and has a few other things that come with a near 40 year old car
modifying cars here in australia is suppper strict, i put a belly pan and a kind of front air dam on it, and i took the passenger mirror off, thats as far as im able to go.
i was also looking in to making a car from scratch that looks like that solar racer but the amount of paperwork and regulations and stuff id have to go through... i dont have the time, the sun is going to turn in to a red giant in another 5bil years

also to add, i drive this car to work 6 days a week which is a 14km round trip, theres not much stop and go but its through the town and its hilly
on sunday i drive on the freeway for a 70km round trip on fairly flat ground,

[jamesqf]

Originally Posted by Vman455

"Frontal" because cars normally move forward through the air, so the high pressure is at the front....

No, what I understand when I hear "frontal area" is what you'd get if you drove straight into a brick wall - the area of the FRONT of the car.

[Hersbird]

I like to think of it as it relates to a train. Doesn't matter if it's a streamlined bullet train or an old box car. Doesn't matter if it's one car or 100, the frontal aera is the same...
And that's how big the entrance to the tunnel better be!

[freebeard]

i was thinking of whether or not i should get a prius roller or maybe a daewoo matiz roller to transfer my electric goodies in to

Now we have a scenario to respond to.

In the last few years, junkyards have quietly filled up with OEM electrical components that are likely superior to what you used in your conversion. Carefully evaluate what you have—batteries, controller and motor. Transferring the old stuff into a new body may not be the best option (although it may also be).

A stanced Prius would get my vote. but you're up against those fenderwell clearance rules.

Also, the frontal area of a pontoon-fendered car is greater that the cross-section at the B-pillar. It doesn't become important until you get to jet planes with their 'area rule'.

[aerohead]

Originally Posted by jamesqf

No, what I understand when I hear "frontal area" is what you'd get if you drove straight into a brick wall - the area of the FRONT of the car.

'Frontal area' is a *******ization of 'projected frontal area'.It is the area of the shadow of the vehicle projected onto a screen,directly behind it,cast by parallel light (sunlight),from directly ahead.You'd get exactly the same shadow if the light source was from directly behind.It's merely a convention used in industry.
The area has nothing to do with the front of the vehicle.

[Frank Lee]

Originally Posted by jamesqf

No, what I understand when I hear "frontal area" is what you'd get if you drove straight into a brick wall - the area of the FRONT of the car.

If you backed the vehicle through a brick wall the result would be the same.

It shouldn't even be called frontal area but it is. We can't even call it "maximum cross-sectional area" because that wouldn't necessarily be right either. Ah well. People call engines "motors" all the time but we live with it.

[Vman455]

Originally Posted by jamesqf

No, what I understand when I hear "frontal area" is what you'd get if you drove straight into a brick wall - the area of the FRONT of the car.

It's not frontal area, but cross section, at the point where the area is greatest.

Are we all being punked? How does someone who has been here as long as you not know what the rest of us mean when we talk about "frontal area"? In your definition, where does the "front" of the car end? Your two examples seem to contradict each other re: what constitutes frontal area.

Don't know who uses that definition, but it seems a misuse of language at best, since the area would be identical to everything you can see from the back.

Um...everyone here. The staff at the A2 wind tunnel. Cyclists. NASA. The EPA. Computer geeks. Pretty much anyone who talks about, works on, experiments with, or is interested in aerodynamic drag.

Of course, if you're just looking for a vocabulary crusade, there are more fruitful areas to address--starting with the general use of "aerodynamic" as a qualified property meaning "streamlined."