A pillar guides

[freebeard]

That goes against common sense (why would manufacturers bother building huge wind tunnels), goes against the steady increase in wind tunnel size and complexity as car manufactures have chased better accuracy, and goes against all the published technical literature on automotive wind tunnel design. I don't know of even one peer reviewed SAE paper that covers a full size car in a tiny wind tunnel.

The big corps have to accommodate big rigs as well as sedans. That a size difference of 2 or 3x right there. They also compete among themselves for photo opportunities.

As for the figures from the tiny tunnel - who knows? Maybe they juggled compensation factors, maybe they made them up, maybe they're all serendipitously correct?

Anything is possible. '[S]erendipitously correct' is the coolest correct.

[JulianEdgar]

Originally Posted by freebeard

The big corps have to accommodate big rigs as well as sedans. That a size difference of 2 or 3x right there. They also compete among themselves for photo opportunities.

You seriously think they build big wind tunnels for photo opportunities?!

You have obviously never had anything to do with any car company.

And as for big rigs - do F1 teams build their wind tunnels to cope with trucks? I don't think so.

I know you have said you don't want to read books, but maybe look at some of the standard texts on car aero testing?

[Cd]

https://issuu.com/magazineproduction...ssue_1_ezinev2

This won't answer any questions, but I thought I would add this here, rather than start a new thread.
This looks like a great magazine.

I've been hesitant to invite Gary Eaker here, because I would love to have a constructive conversation, rather than having him exposed to bickering.
Perhaps later this week I can present the questions to the guys at A2.
Gary also has another tunnel called the Aerodyne wind tunnel.
The Aerodyne does have a moving floor, a mechanism to spin the vehicle wheels, yaw movement, and even floor suction.

He knows his stuff.

[freebeard]

Not any car company but I have worked for major software corporations. I suspect the car companies lean more into marketing.

It's not that I don't want to read books. My attention span has been ruined by hyperlinks. Well, that and the 6-month or greater latency.

Cd — well, there's your counterexample. It's an amazing periodical, if only for the side-scrolling format. Page 58 on CFD was interesting, but it talks about algorithms (Implicit Large Eddy Simulation) at the expense of High Performance Computing, where I am more familiarized.

I know this isn't the thread that had the Camaro, but I found this:


www.allpar.com/threads/pro-stock-dart-launched

It doesn't show in this view but the wheelwell's trailing edges are radiused, Insight style.

[JulianEdgar]

Originally Posted by Cd

https://issuu.com/magazineproduction...ssue_1_ezinev2

This won't answer any questions, but I thought I would add this here, rather than start a new thread.
This looks like a great magazine.

I've been hesitant to invite Gary Eaker here, because I would love to have a constructive conversation, rather than having him exposed to bickering.
Perhaps later this week I can present the questions to the guys at A2.
Gary also has another tunnel called the Aerodyne wind tunnel.
The Aerodyne does have a moving floor, a mechanism to spin the vehicle wheels, yaw movement, and even floor suction.

He knows his stuff.

The Aerodyne one looks like another small wind tunnel - but much better than the other one. Specs (test area, power) are about half a full-size tunnel.

Invite whomever you wish - but as as been said repeatedly to me here, everyone should expect to be challenged.

[woodstock74]

Originally Posted by Cd

https://issuu.com/magazineproduction...ssue_1_ezinev2

This won't answer any questions, but I thought I would add this here, rather than start a new thread.
This looks like a great magazine.

I've been hesitant to invite Gary Eaker here, because I would love to have a constructive conversation, rather than having him exposed to bickering.
Perhaps later this week I can present the questions to the guys at A2.
Gary also has another tunnel called the Aerodyne wind tunnel.
The Aerodyne does have a moving floor, a mechanism to spin the vehicle wheels, yaw movement, and even floor suction.

He knows his stuff.

For what it's worth, Aerodyn only spins the wheels, there is no moving belt underneath the car. They manage undercar flow via a suction platten.

Windshear has the full simulation with the entire vehicle on a moving belt, similar to a proper scale model tunnel but 1:1.

[JulianEdgar]

Today I have found two papers that cover turning vanes.

One paper showed that aerofoil sections are much better than flat plates (what I'd found in my testing) and the other showed that really good gains can be made on older cars' A-pillars by the use of turning vanes (which also supports what my tuft testing showed).

So I'd like to fit them to my Insight, but the same old problem remains. No matter how hard I look, I cannot find an aerofoil-shaped aluminum or plastic extrusion that I can easily buy by the metre that's roughly the right size.

[freebeard]

How to Print Thin Wall - PlanePrint | Big Bobber

I just finished listening to an hour on fine-tuning printers and a filament shoot-out: 3D printing engineering parts: PLA vs ASA vs PC vs PP vs nylon vs tough resin. Australian school kids on their way to Abu Dubai.

I'm imagining vanes on a 1928 Ford.


https://cdn.barrett-jackson.com/stag...nt_3-4_Web.jpg

[serialk11r]

Okay so this isn't 100% on topic, but now that I fixed most of my suspension clunking, the wind noise is really getting on my nerves, so today I tried various bits of tape on one side of the car to see if I could reduce the howling noise.

I put a lot of tape at the top of the mirror across the gap to the body, and...zero effect on sound. That makes sense to me, because if you look at CFD images, the mirror usually ends up guiding air into the channel between it and the body, and prevents a vortex from forming. The vortex instead starts above the mirror, so if you have side mirrors, I'm guessing guides would be most effective above the mirror.

I'm going to try mini aluminum VGs, and just wear earplugs if it doesn't help. It probably doesn't take that many to disrupt the formation of the A pillar vortex.

[JulianEdgar]

Originally Posted by serialk11r

Okay so this isn't 100% on topic, but now that I fixed most of my suspension clunking, the wind noise is really getting on my nerves, so today I tried various bits of tape on one side of the car to see if I could reduce the howling noise.

I put a lot of tape at the top of the mirror across the gap to the body, and...zero effect on sound. That makes sense to me, because if you look at CFD images, the mirror usually ends up guiding air into the channel between it and the body, and prevents a vortex from forming. The vortex instead starts above the mirror, so if you have side mirrors, I'm guessing guides would be most effective above the mirror.

I'm going to try mini aluminum VGs, and just wear earplugs if it doesn't help. It probably doesn't take that many to disrupt the formation of the A pillar vortex.

It might be better to tuft test the side glass first, so that you can actually see what is happening with the airflow.