Designing better side mirrors...

[NeilBlanchard]

Video mirrors are a gray area - they actually comply with the letter and the spirit of the law, but so far I have had to put my stock mirrors back on for the annual safety inspection. The inspectors don't want to be the test case; but I have never had any other issues with them in the nearly 4 years that I've had them.

[aerohead]

Originally Posted by plasticuser

Hi all,

I have been looking at my huge F150 side mirrors, which are a square foot each, and I know I can do better.

I have decided to make some fiberglass replacements that meet the legal requirements for seeing 200 ft behind me, but which are far aerodynamically smaller, to reduce drag.

I've watched a lot of wind tunnel tests, re-watching again and again what happens with the air over the mirrors and it is a mess. I think I might be able to do better.

I'll make some models and post some photos and take ideas and feedback. I'll make more models...

The idea here is to work out what is more efficient, and doesn't create turbulence right against the glass where you can hear it.

Has anyone already done any work like this?

Subaru and AeroVironment choose to move their mirrors outward into slower air away from the A-pillar area where air velocity is highest.

[coyoteX]

What about placing the mirrors forward, hugging the top of the fender like the Plymouth Superbird 1970 era, or bullet shaped mirrors mounted fender top like older cars in Japan?

[plasticuser]

Fender-positioned mirrors do not meet the "200 feet behind" requirement.

If anything, moving them back puts them into slower air, although in a truck, simply moving them higher minimizes their interaction with the truck.

[shovel]

I've noticed quite a few factory mirrors on cars that have seemingly aero treatments...





- but I've also wondered why one couldn't build a mirror with multiple panes, vertically aligned like vertical blinds so they appear as one solid surface to the driver but allow air to pass between them. Wouldn't that reduce the pressure differential between the nose and the wake of the mirror and effectively reduce drag?

[Xist]

Originally Posted by shovel

Objects in mirror are less Obsessed Nicolas Cage than they appear.

[shovel]

yeah but... look at the little nubby *******s on the case of the mirror.. i don't know what kind of car that is or else i'd try to find an outside photo.

[NeilBlanchard]

Those are little turbulators that reduce the noise a bit.

[Frank Lee]

Raised dots for the air's pleasure

[Vekke]

Here is few pictures of my 3d printed aero mirrors, no blind spots with these:






Those will lower the frontal area in normal european car for 0.03 m2 and Cd 0.01-0.03 depending on the vehicle. In fuel consumption that means 0.1 liter less fuel burned at 100 km/h speed.

Mirror can be downloaded here: https://grabcad.com/library/aerodyna...ror-for-cars-1