Aerohead's going to the wind tunnel! We're passing the hat to help with costs.

[aerohead]

Originally Posted by freebeard

In hindsight, that was good foresight.

Can you show a picture of the part that's no longer there? Fore or aft of the tailgate?

It's behind the blue painters tape line,completing the bedcover,on top of the primary tail section.It starts a smidge behind the tailgate due to the overhang of the bedcover.

[aerohead]

Originally Posted by Ardent

Looks like it's actually propylene glycol or mineral oil: Smoke Generator - Aerolab

Does the hood bulge add to the airflow encountered by the side mirrors?

Yes,it is propylene glycol.'must keep away from those bowls of stupid in the morning.
I can't give a definitive answer to the effect of the hood blister.
Without it,tufts and rain streaks indicate that the air is traveling transveresly at the bottom of the A-pillars.So the mirrors would be getting a nice blast of accelerated air there without the blister.The serpentine airflow near the mirrors/doors I've seen on other cars without such a hood architecture.
To allow visibility,the top of the blister is narrow in comparison to the hood,and the sides,you'd think,would tend to channel air transversely as well,especially when it hits the Plexiglass diverters (which allow the Registration and Inspection stickers to be viewed).
It is possible that this entire region is encountering Prandtl's lines of discontinuity anyway,as far as streamline displacement,and may not make that much of a difference.
The air does push water uphill on the blister,so it is imparting a vertical flow component which might alleviate some of the transverse intensity at the A-pillars.
And the ram pressure at the cowl is reduced,indicating higher velocity/lower pressure.
In the smoke video,the air climbs the blister,jumps the gap at the cowl,then hustles up the screen.
Here is an earlier tuft study.The blister is in place,and it appears not to have too much significance for downstream flow.

If I make it back to Darko,it would be a relatively easy thing to remove the blister and do A-B comparisons of overall drag effects.The blister is one of very few mods which can actually be removed without major surgery.
'hope this long rambling helped.

[Ardent]

Originally Posted by aerohead

'hope this long rambling helped.

I think so. It would help if I could see your motions as you talk.

I'm fascinated that the same air that goes above the headlight travels below the door handle and then over the corner of the tailgate.

[aerohead]

Originally Posted by Ardent

I think so. It would help if I could see your motions as you talk.

I'm fascinated that the same air that goes above the headlight travels below the door handle and then over the corner of the tailgate.

I have a 3-ring binder of flow images at home but that won't help us today.
I'll link some off GOOGLE (automotive aerodynamic flow images)
http://www.exa.com/images/efficiency_truck.jpg
http://gallery.ensight.com/Images/Ke...amlines-XL.png
http://www.speedhunters.com/wp-conte...nt-Aero-22.jpg
http://www.cd-adapco.com/sites/defau...?itok=NQb93_a9
http://www.deskeng.com/de/img/stream...he-prius_1.jpg
Between pressures,velocities,and deflections,we end up with this flow pattern.
I'm not experienced enough to explain what's happening.10,000-hours inside a wind tunnel would be a big help.

[Cd]

I'm surprised no one honked and flagged you down.

I still don't see how it could have just fell off. Was it due to a parachute effect caused by the missing piece of your underbelly cover ?

What held it on ? Surely you had some heavy duty bolts, eh ?

[aerohead]

Originally Posted by Cd

I'm surprised no one honked and flagged you down.

I still don't see how it could have just fell off. Was it due to a parachute effect caused by the missing piece of your underbelly cover ?

What held it on ? Surely you had some heavy duty bolts, eh ?

The cone was attached to both the trailing face of the bedcover,and top of the boat tail.
When the plumbers tape let go,the drivers side of the tail displaced rearwards,pulling the screws out of the bedcover bulkhead,leaving only a single screw attached at the trailing end of the cone.
It would have been easy for the air to catch the front of the cone,lifting it,and tearing the remaining screw out.
I've been running 44-psi in the tires and while they're great on smooth road,they transmit the smallest irregularity from the road to the entire vehicle.
HWY-380 is like the Lunar surface.With constant traffic on the open portion,there's no way to maintain it,short of shutting the entire thing down.
Even I-35 is 'washboarded' on the concrete sections.It just hammers the hell out of the truck.
I suppose that I'll be forced to lower the pressure in the tires.Something I didn't want to do.Even if nothing had gone awry.

[freebeard]

So — coulda been worse? You could slump-mold clear plastic in your concrete form and make a big ol' 3rd brakelight.

[aerohead]

Originally Posted by freebeard

So — coulda been worse? You could slump-mold clear plastic in your concrete form and make a big ol' 3rd brakelight.

That would be fun to do.Just to do it.The Plex seems to have a memory,and wants to return to a flat sheet when heated.If I had a sealing perimeter to clamp to it,and a pizza oven,I could use air pressure to blow the hot,softened plastic down into the mold until it cooled.
Good one freebeard!

[Cd]

So, Phil - somewhere along the side of the road is the tail section, complete with your license plate too, right ?

Seems to me that some road crew just might come across it and turn it in.
You just might check with the DPS office.

Shame about those tail lights. We all liked the look you had going with it.

[aerohead]

Originally Posted by Cd

So, Phil - somewhere along the side of the road is the tail section, complete with your license plate too, right ?

Seems to me that some road crew just might come across it and turn it in.
You just might check with the DPS office.

Shame about those tail lights. We all liked the look you had going with it.

Boat tail's okay,I lost the end of the 'Poco-Loco' aeroshell which attached on top of the boat tail.I'll resurrect it in fiberglass when weather and time permits.