Aerodynamic Streamline Template Picture Library

[kach22i]

Originally Posted by California98Civic

I have never been very confident that the plan view image is correct. It was for the greenhouse, when I was experimenting with raised trunk lids. But here you go, for general review.

It's better than nothing, and a start.

I believe the same template position and scale used in side view must be applied to the top view for monolithic bodies.

For 2-Part bodies, I believe some have advocated a 10:1 ratio over the 5:1 ratio, meaning a canopy twice as long (not half as long as you show).

[aerohead]

Originally Posted by California98Civic

I have never been very confident that the plan view image is correct. It was for the greenhouse, when I was experimenting with raised trunk lids. But here you go, for general review.

Historically,it looks like some of the most successful low-drag record cars used 2-dimensional 'Templates' for plan-view tapering.
The air on the sides of a car is slower than over the roof/greenhouse and at a higher pressure, and with less kinetic energy contained,may not be able to support as much camber as over the roof without risk of separation.
Until I learn more,I'd recommend the 3.94:1 symmetrical wing section profile from Hoerner's drag table.
It should be at the AST Part-C thread.
let's try an image

[Thenorm]

Originally Posted by aerohead

Historically,it looks like some of the most successful low-drag record cars used 2-dimensional 'Templates' for plan-view tapering.
The air on the sides of a car is slower than over the roof/greenhouse and at a higher pressure, and with less kinetic energy contained,may not be able to support as much camber as over the roof without risk of separation.
Until I learn more,I'd recommend the 3.94:1 symmetrical wing section profile from Hoerner's drag table.
It should be at the AST Part-C thread.
let's try an image

is this what you meant by using profile template on top? doing this on the 2014 mazda 3 and the AST did follow one of the body contour lines (I think it was the belt line just below the windows.

[euromodder]

Originally Posted by Thenorm

Up has a good shape. follows template right from the windscreen.

By the looks of it, I could extend the roofline from 7.5° to about 15°
(with a 1 m / 1.1 yard hitch-mounted extension )

[aerohead]

Originally Posted by Thenorm

is this what you meant by using profile template on top? doing this on the 2014 mazda 3 and the AST did follow one of the body contour lines (I think it was the belt line just below the windows.

*My original thinking was to, 1st establish the roof contour based upon the 'Template',then find the location of max. camber along the body side and apply the identical contour along the sides.
*After looking at more record cars,and since considering that a car would need to be more narrow than what a 'pure' streamline body of revolution-based half-body would require,that it would be prudent to use the 2-dimensional flow section of 3.94:1 thickness ratio for the sides.

The narrower profile of the wing section profile better fits the needs of production automobiles and also addresses the issue of the slower air down the sides.

[kach22i]

Originally Posted by Thenorm

is this what you meant by using profile template on top?

Using the link Aerohead provided, and using your "Zero Point" (assuming it was accurately located) I got this:

Originally Posted by aerohead

It should be at the AST Part-C thread.
let's try an image

The width should be double the height to be truly accurate, right?

[Thenorm]

i was reading the Jalopnik article how nobody is buying crossover coupes. Turns Out No One Wants A Crossover Coupe Anymore

anyways, here's 5 crossovers and their CD. none of them are particularly good





Honda Accord Crosstour, Cd 0.36 estimated

Acura ZDX, Cd 0.35

BMW X6, Cd 0.35

BMW 3 GT, Cd 0.29

BMW 5 GT, Cd 0.31

[kach22i]

Originally Posted by Thenorm

............anyways, here's 5 crossovers and their CD. none of them are particularly good

That's kind of odd, I can only offer some conjecture; must be the high ground clearance combined with an messy underbelly which raises the Cd despite a close conformance to the aero-template.

A mystery really, I'm just guessing - but it would seem likely.

[3-Wheeler]

Sorry, I reconsidered my post.

Jim.

[aerohead]

Originally Posted by kach22i

That's kind of odd, I can only offer some conjecture; must be the high ground clearance combined with an messy underbelly which raises the Cd despite a close conformance to the aero-template.

A mystery really, I'm just guessing - but it would seem likely.

None of the vehicles have the body plan taper which would reduce their drag.The carmakers aren't willing to narrow the rear axle,as with the EV1 and Insight-1.
The roofline just isn't enough to do the job.