Civic hatchback aerodynamics

[basjoos]

The side skirts are suppose to keep the air flow running smooth and parallel under the car and reduce the amount of turbulence toward the back of the vehicle. I haven't run into any noticable crosswinds yet, but haven't noticed any changes in the car's behavior to the bow waves coming off passing semi's. The next step in the project are front wheel well skirts.

[Mighty Mira]

Originally Posted by basjoos

The side skirts are suppose to keep the air flow running smooth and parallel under the car and reduce the amount of turbulence toward the back of the vehicle. I haven't run into any noticable crosswinds yet, but haven't noticed any changes in the car's behavior to the bow waves coming off passing semi's. The next step in the project are front wheel well skirts.

I am certainly looking forward to that attempt. Your car is an inspiration to all of us.

[MetroMPG]

Agreed - I love your take no prisoners approach here, Basjoos.

Now, those front wheel skirts... can you say whether you're going to attempt the full meal deal, or some variation on gap-fillers between the bodywork and tires? And if it's the full meal deal, what approach to permit clearance for steering?

[basjoos]

I plan to do a full cover using 4 low-clearance conveyer rollers (1/2" x 6") spaced so they only contact the edge of the tire and push the cover outward during low speed turns. It will remain closed during high speed lane changes, etc. It will be hinged at the top with a piano hinge and with springs at the bottom to hold it shut when the tires aren't pushing it open. I hope to fabricate it from a steel sheet, but if my metal skills aren't up to the challenge, I'll make the cover from a framework of aluminum bar stock covered with coroplast.

[mrlegoman]

Pics are not working. Can you post them again?

[basjoos]

<IMG style="; WIDTH: expression(this.width > 800 ? 800: true); max-width: 800px" alt="" src="http://img.photobucket.com/albums/v417/MikeMariettaSC/80MPG%20Honda%20Civic/Civic7.jpg" border=0>

<IMG style="; WIDTH: expression(this.width > 800 ? 800: true); max-width: 800px" alt="" src="http://img.photobucket.com/albums/v417/MikeMariettaSC/80MPG%20Honda%20Civic/CivicCS.jpg" border=0>

<IMG style="; WIDTH: expression(this.width > 800 ? 800: true); max-width: 800px" alt="" src="http://img.photobucket.com/albums/v417/MikeMariettaSC/80MPG%20Honda%20Civic/CivicCbS.jpg" border=0>

<IMG style="; WIDTH: expression(this.width > 800 ? 800: true); max-width: 800px" alt="" src="http://img.photobucket.com/albums/v417/MikeMariettaSC/80MPG%20Honda%20Civic/CivicCaS.jpg" border=0>

[GasSavers_civicminded]

[JanGeo]

Do we know for certain that the front wheel wells are a source of drag being open.
Are they letting air out from under the car?
Do they need to be fully enclosed?
How about smooth hubcaps and smaller openings around the tires to the fender instead of enclosing them entirely.

[MetroMPG]

Enclosed arches are best. Seems only logical. See the Ford Prove V prototype & any number of one-off Bonneville high-speed designs.

Next best is smooth wheel covers and tight tire-arch tolerances: the Prius has noticably smaller than "normal" tire-arch gaps).

A radiused shape at the "aft" end of the arch bodywork permits air exiting the wheel well to transition better to the sides when the arch is left "open": see the honda Insight, VW 1 Liter prototype.

[ZugyNA]

Has anyone thought of using one of those snow saucers to cover a wheel well?

Or maybe an old satellite dish of some type?

Maybe a hard type tire cover as on an RV?