Swift brick?

[Achtung]

Originally Posted by Arminius

Perhaps Landon can try it out on his cardboard box?

I like it! Somebody start a list of things for Landon to do with this cardboard box.

Originally Posted by basjoos

It just takes 15 minutes to build a wiper windscreen out of sheet metal and pop rivet it to base of your hood. This simple mod gets the wipers out of the airflow.

IMO, this would be the best way to go. Removing and replacing your wipers is a hassle to do every time it rains. Just paint it black, it won't show up as much. Or if you could, paint it the same colour as the car. Then you could tell your friends you got the extremely limited edition Aero 240.

[DifferentPointofView]

don't they make wiper cowls just for this purpose that doesn't require pop-riveting stuff to your hood? I'm sure they're over-priced, but some of us like our paint once I get a large enough plastic thing, I'm gonna make my own. and my own sun-visor with vents to go along.

[aerohead]

Originally Posted by Arminius

Has anyone here experimented with putting their wipers in the vertical position when they are off? I know people do that, but I haven't seen any evidience that it works. It seems common sense to me, but I want emperical evidence.

Perhaps Landon can try it out on his cardboard box?

Arminius,it may not make a difference.Since modern cars pull ventilation air from the cowl area,immediately adjacent to the windshield base,this area is usually denoted as an area of stagnated flow reaching quite a bit forward over the hood.As in attached vortices,the free field flows over this region as if it were solid.Typically,the wipers are embedded within this region and the airstream doesn't actually impinge on them.Removing them altogether on my CRX demonstrated no measureable difference in performance at top speed,and I personally consider them a dead-end with respect to mileage improvement.

[Arminius]

Originally Posted by DifferentPointofView

don't they make wiper cowls just for this purpose that doesn't require pop-riveting stuff to your hood? I'm sure they're over-priced, but some of us like our paint once I get a large enough plastic thing, I'm gonna make my own. and my own sun-visor with vents to go along.

There are carbon fiber cowls out there. If I could save $200 in gas within the first two years by buying one, I might consider it.

Originally Posted by aerohead

Arminius,it may not make a difference.Since modern cars pull ventilation air from the cowl area,immediately adjacent to the windshield base,this area is usually denoted as an area of stagnated flow reaching quite a bit forward over the hood.As in attached vortices,the free field flows over this region as if it were solid.Typically,the wipers are embedded within this region and the airstream doesn't actually impinge on them.Removing them altogether on my CRX demonstrated no measureable difference in performance at top speed,and I personally consider them a dead-end with respect to mileage improvement.

Possibly, but the wipers on the 2005 Civic sit very high above the hood compared to most cars. The wind coming over the hood hits the windshield, moves upward, and then hits the wipers. I'm used to my Ford Escape, which had a rather high hood and the wipers were below the hoodline.

[aerohead]

Originally Posted by Arminius

There are carbon fiber cowls out there. If I could save $200 in gas within the first two years by buying one, I might consider it.



Possibly, but the wipers on the 2005 Civic sit very high above the hood compared to most cars. The wind coming over the hood hits the windshield, moves upward, and then hits the wipers. I'm used to my Ford Escape, which had a rather high hood and the wipers were below the hoodline.

Ah yes,a neighbor has a late model CIVIC and the hood and windshield form basically a continuous line.I should be taking my own advice (this is happening a lot lately) and consider each vehicle on a case-specific-basis.I might mention that at Bonneville,I taped a cardboard "cowl" onto the CRX,as a "fillet",to smooth the flow onto the windshield.To a thousandth of a mile per hour,it showed nothing,however,the hoodline and windshield differ significantly from the late model cars and certainly could react more favorably to such mods.Good luck with the carbon fiber and let us know how it all shakes out.

[Harpo]

Originally Posted by Arminius

Possibly, but the wipers on the 2005 Civic sit very high above the hood compared to most cars. The wind coming over the hood hits the windshield, moves upward, and then hits the wipers. I'm used to my Ford Escape, which had a rather high hood and the wipers were below the hoodline.

With Upper Grill Block, I've noticed that below 50-55mph the drops that form below the wiper at rest migrate with the flow over the hood fairly uniformly. However, after 55mph it appears that some turbulence (at least non-laminar flow) sets in forward of the wiper, actually causing the dops to stagnate, and sometimes retreat to toward the front. I can't determine whether it's a function of the wiper blade interference drag at that speed, or just that the airflow changes off the hood making a low pressure area just forward of the lower windshield.

It would be intersting to witness it without the Upper Grill Block to see if it's altered.

[DifferentPointofView]

My wipers definitely stick out. Even though hose tests aren't very good, You can tell just by looking. Failed the hose test anyway.

[aerohead]

Originally Posted by Harpo

With Upper Grill Block, I've noticed that below 50-55mph the drops that form below the wiper at rest migrate with the flow over the hood fairly uniformly. However, after 55mph it appears that some turbulence (at least non-laminar flow) sets in forward of the wiper, actually causing the dops to stagnate, and sometimes retreat to toward the front. I can't determine whether it's a function of the wiper blade interference drag at that speed, or just that the airflow changes off the hood making a low pressure area just forward of the lower windshield.

It would be intersting to witness it without the Upper Grill Block to see if it's altered.

I believe carmakers design in a region of stagnated air adjacent to the windshield to tap for cabin ventilation.On the T-100 the rainwater stops about a foot (300-mm) in front of the windshield base.Perhaps you've seen NASCAR racers drafting.If you look,you'll notice that the combustion air inlet is positioned at the windshield base to take advantage of this pressure peak.Since they're drafting,there's no ram-air available at the grille and they'd lose a tiny bit of HP if they tried to harvest that area.I suspect that your windshield wipers are "harbored" within this stagnant pool of air.Wind-tunnel smoke-flow images usually show the air deflecting over this whole area,as the flow is diverted by the bubble.

[DifferentPointofView]

I'm guessing they put them there (wipers) to act like the tailgate of a truck and create the air to go back down the windshield, into the cabin vent area, back up, into the wipers, back down the windshield, while the rest goes over it. So removing your wipers wouldn't really help much, you'd just have no wipers. makes sense.

[Arminius]

Motors be damned! I'm going to install a switch to turn the wipers off, after I install more aerodynamic wipers.