Random Wind Tunnel and Smoke Pictures Thread

[freebeard]

The SM's body was developed in the wind tunnel and "sculptured" by the wind.

I'm thinking put a clay model in the wind tunnel and use a sand blaster instead of a smoke probe.

Possible repost, I'm losing track.

I wish there were some way to scrape the comments on a multipage thread, throw out one line comments and concatenate the rest into a single file.

[Cd]

Originally Posted by kach22i

Lexus LFA wind tunnel aerodynamic testing | Planes, Trains & Automobi

Look at how perfect the flow looks on the LFA. It hugs the roofline, yet the car has a Cd of .40.

Another example of how smoke testing is nearly useless on looks alone.

[kach22i]

Originally Posted by freebeard

I'm thinking put a clay model in the wind tunnel and use a sand blaster instead of a smoke probe.

I spent 15 minutes looking for a car I've seen at a car show (Eyes on Design) which would have been nice to post right about now.

The car is a hand made replica of a one-off aerodynamic car made in he mid-1920's. I spoke with the builder/owner, located in Indiana (I think).

Anyway, the way the shape was achieved was steel plate cutouts were made matching the windshield and radiator shape and areas.

A blower or wind machine of some kind placed in front, and clump fulls of sand were tosses into the airflow. The sand would hit the steel plates and deflect/move around the plates/objects. The pattern of this sand migration/movement was recorded somehow and replicated to form the aluminum body.

If or when I ever find my pictures, I'll post them. This same car was on Hemming's or some other site within the last 9 months as a feature.

[aerohead]

Originally Posted by Cd

Look at how perfect the flow looks on the LFA. It hugs the roofline, yet the car has a Cd of .40.

Another example of how smoke testing is nearly useless on looks alone.

With only a glimpse of the centerline flow,we're denied a look at the warts and moles created by the down-force induced drag.
'Performance' car really is an oxymoron.'good thing these stylists aren't allowed into the aerospace industry,or we'd have a lot of really 'cool' looking aircraft falling from the sky.

[freebeard]

As luck would have it my camera had failed [temporarily] while I was on the streets of Wendover at night, but some of the shop trucks had massive encrustations of salt. It was like a competition.

OMG, if your cooling system puke can vented into the wheelwells, you might inadvertently collect metadata on anonymized salt particles.

[CFECO]

It is obvious where the High CD comes from from the photo, look at the smoke leaving the rear wing it is forced up, for downforce at the cost of drag. What is the CD for a F1 or Indycar, something like a 5? By they could run on the ceiling at track speed.

[aerohead]

Originally Posted by CFECO

It is obvious where the High CD comes from from the photo, look at the smoke leaving the rear wing it is forced up, for downforce at the cost of drag. What is the CD for a F1 or Indycar, something like a 5? By they could run on the ceiling at track speed.

From an SAE Paper from the latter 1980s,the F1/Indycar body was:
*Cd 0.24 by itself.
*Cd 0.54 with wheels.
*Cd 1.2 with wheels and wings.
*They were turning laps at Indy at 235-mph.
*At 150-mph their dynamic 'weight' was 5,000-lbs,for a car of 1,500-lb static weight.
*And yes,they could easily race inverted.

[CFECO]

Ha Ha...5, I was way off LOL. I always found it amazing that the full size, iron engine, pushrod, naturally aspirated, single 4 barrel carb, on gas, NASCAR cars were almost as fast as the Indy cars. Must be something, heading into turn 1 at Indy and not lifting....WHEEEE

[California98Civic]

Originally Posted by aerohead

From an SAE Paper from the latter 1980s,the F1/Indycar body was:
*Cd 0.24 by itself.
*Cd 0.54 with wheels.
*Cd 1.2 with wheels and wings.
*They were turning laps at Indy at 235-mph.
*At 150-mph their dynamic 'weight' was 5,000-lbs,for a car of 1,500-lb static weight.
*And yes,they could easily race inverted.

I shared this with my wife... and immediately wondered about a day when driver-less indy race cars drive on wild tracks with inverted sections, because the fear of driver injury had been eliminated. The new design problems and possibilities, the thrill for audiences of watching in person as full-sized cars do almost aerobatic maneuvers. Day dreaming.

[CFECO]

Just like Military Aircraft, the machine has out-performed the humans ability to ride along. Drone Unlimted race cars, 300 mph, upside down, 6g turns, Wheeee!