Moustaches for cars... looking for a source/donor

[Otto]

Proper orientation of the bristles to the airflow is important.

NASA (Bushnell et al) have been looking at this and compliant wall surfaces, at least for 30 years that I know of. Such compliant wall surfaces (bird feathers, seal fur, etc.) dampen oscillations of flow and von Karman vortices, so aid streamlining. Eskimo kayaks with seal skin covers may have taken advantage of this.

Recently, NASA has looked at bristles on trailing edges to quieten noise, and studied Barred owls' trailing edge feathers, for application to quieten airliners, etc.. See also serrated trailing edges on Boeing 787 engine nacelles.

For our purposes, such bristles may be useful for not just front air dams, but also to smooth flow under the car, at trailing edges of wheel fairings, etc..

You are on the right track. Thanks for sharing.

[botsapper]

Anyone want to test it? Plausible flow control & possible beneficial aero effect.

http://www.newscientist.com/article/...f-flights.html

Air dam for motor vehicle - Patent 4585262

[wyatt]

If you are worried just about the abuse that it will take, I have read several testimonials to the durability of the ~4" black lawn edging. Lots of people have hit curbs, rocks, road debris, etc. with little/no visible damage. They cut out the center some to allow more air under the car, and have had good success with them. A couple advantages, the lawn edging is readily available at any store that carries gardening supplies (Wal-Mart, Lowe's, Home Depot, any garden center, etc), and since it's the end of the year, you will get what you can find for even less than the normally low price! I bet you can do your mod for less than $10, and have enough left over to replace the whole thing if anything would happen to it.
Here's a link: Home Depot Air Dam

[COcyclist]

You don't wanna just go with the tried and true lawn edging?? It's flexy, black and super cheap.

(Wyatt beat me to the click)

[ac7ss]

Originally Posted by COcyclist

You don't wanna just go with the tried and true lawn edging?? It's flexy, black and super cheap.

(Wyatt beat me to the click)

The original poster stated that they use dirt/uneven roads. (Heck, I would have trouble at some business driveways.)

How about this? The skirts used behind RVs to keep rocks from hitting the car they pull around. About $50-60 for a set at first glance.

[moorecomp]

Originally Posted by ac7ss

The original poster stated that they use dirt/uneven roads. (Heck, I would have trouble at some business driveways.)

Hello,
That was my project that the above link referenced. I installed the Home Depot air dam. If you look at my profile picture albums, you will see I do live on "dirt/uneven" roads. This is my front yard and driveway.

3/10ths of a mile to the road. Gotta keep it clear in the winter ourselves, as it is considered a seasonal road and not plowed. They do grade it a couple of times a year though. I have about 4"-5" of clearance below my air dam, and have had no scraping issues so far. Remember, the air dam has been recommended by experts on this site as not needing to be any lower than the lowest bits on the underside of your vehicle. That's what I did.

[ac7ss]

Not as bad as I feared for the road. (Logging roads up here are a little more severe.)

If I needed it, I would use the Home Despot air dam, but my car is properly designed in that area. (Finally got to see it up on the lift. nice and smooth.)

[Bicycle Bob]

Just use Coroplast with the grain vertical, and make some slits. Make a slight score on the back along the top of the slits to establish a consistent bend line. Back it up with sponge rubber near the self-hinge at the top to encourage full return to position, unless you like the shape it sets into. For really tidy work, use two layers of Coroplast, with staggered slits trimmed to the web on both sides. Use some foam plumbing insulation to soften the bottom edge.

I've seen RVs with broom like whiskers at the back, too, of a suitable scale, or you could raid a discount store for household brooms to hack.

For extra fun, draw teeth along with the 'stache, but leave off the lower jaw. Eat the road!

[hypermiler01]

rubber big rig mudflaps

[ShadeTreeMech]

dirt roads are evocative of rally cars.

rally cars go very fast down dirt roads and are fast for their size.

yet I've never seen one with an air dam; they all have an underbelly pan.

Is the underbelly pan more likely the best option?

And the bristles may help up to a certain speed, but at the speed they're really needed (ie highway speeds) they're liable to fold shop and threaten to catch fire on the exhaust piping.

BTW thanks for the good laughs, I'm still wiping tears from my eyes by laughing so hard!