Taking air from a Low Pressure area

[j-c-c]

I fully understand leaning on "luck" is antithetic to our fact/logic based discussions here. I also think what the final intended purpose is of the exhausted air from applying any suction attempts is probably irrelevant, as long as that exhausted air does not cause other un intended consequences. I have not addressed any Reynolds calculations, and If i was to take a wild guess, I'm in the area of 50% of chord length for the proposed inlets.

And while I am wandering around outside the box, I'm exploring putting the suction fans on a variable brake line pressure sensor timed relay and a soft power off, meaning they only kick on under real braking, ie not a tap, and they stay on awhile while car re accelerates after leaving a corner, these are both times, when rear tires can benefit from maximum DF, or the time I want maximum DF from the rear wing. Of course this all depends if I can keep the rear smaller sized rotors within a proper temp.

https://allstarperformance.com/in-li...n-hd-all13009/

When car finally gets to A3, it will be a real pass/fail easy test of efficacy.

[Frank Lee]

No rules? I'd use a big elevated wing set for slight to no downforce on the straights and increasing downforce as brakes are applied, ultimately being a complete air brake if really hard on the brakes. Mercedes had an airbrake racer back in the day. And I dimly recall seeing a video sometime in the last few years about a supercar with left and right "ailerons" that in addition to downforce and braking, were individually activated for cornering assistance.

P.S. This isn't what I remembered but it's one example: https://www.thedrive.com/tech/22150/...going-aircraft

[j-c-c]

Yes, that is along the lines of my thinking, getting the wing into better airflow upon braking by using the brake fans in a low pressure area, and then letting air stream rise ever so slightly above (?) the wing when fans turn off.

Not that I'm rule bound, but it might get me under the wire as not being a bonafide active movable aero device, until the rules change.

Here is a likely candidate for fan control, mounted within drivers reach.

https://www.galco.com/buy/SSAC/TRS12...kaAqfOEALw_wcB

[freebeard]

Frank Lee "P.S. This isn't what I remembered but it's one example:..."

Right there on the show floor, the big black “Centripetal Wing” pitched, dipped, danced, and cavorted in lurid fashion on the busy rear deck of the car, like an enormous vulture trying to lift off with a bloated red carcass.

Pagani Huayra

https://d3lp4xedbqa8a5.cloudfront.ne...ani-Huayra.jpg

[Frank Lee]

That could be the car; I thought they formed rear trailing edges like ailerons but haven't found anything like that.

[freebeard]

They lay against the bodywork, more like an air brake,


https://images.hgmsites.net/hug/fina...00649448_h.jpg

Sorry for the pic size, are you still on dial-up?

[aerohead]

Originally Posted by j-c-c

Yes, that is along the lines of my thinking, getting the wing into better airflow upon braking by using the brake fans in a low pressure area, and then letting air stream rise ever so slightly above (?) the wing when fans turn off.

Not that I'm rule bound, but it might get me under the wire as not being a bonafide active movable aero device, until the rules change.

Here is a likely candidate for fan control, mounted within drivers reach.

https://www.galco.com/buy/SSAC/TRS12...kaAqfOEALw_wcB

As a thought experiment,I'd have you consider having the fans fed from high pressure NACA submerged inlets,and valve them off on everything except corners,reducing the power load of the fans as much as possible,and guaranteeing that maximum available CFM delivered passively,before you have to pay for artificial static pressure and the electricity.
Do you know how many Btus must be extracted at varying velocities,and how much air-cooling required?

[j-c-c]

No on the BTU removal calc's. The current discs were installed previously with a much less robust power train. So keeping them if usable, is a benefit. I suspect with all the variables in my application, it will boil (pun intended) down to rotor heat indicator paints with on track testing. Keep in mind my goals, the removing air by way of fans mainly is to optimize my rear wing efficiency and its height placement. The fans linked previously are in the 3.5A current range each, acceptable for me.

The NACA inlet duct suggestion raises another question, are they any useful benefit located in a low pressure area?

[freebeard]

rotor heat indicator paints > calcs

[aerohead]

Originally Posted by j-c-c

No on the BTU removal calc's. The current discs were installed previously with a much less robust power train. So keeping them if usable, is a benefit. I suspect with all the variables in my application, it will boil (pub intended) down to rotor heat indicator paints with on track testing. Keep in mind my goals, the removing air by way of fans mainly is to optimize my rear wing efficiency and its height placement. The fans linked previously are in the 3.5A current range each, acceptable for me.

The NACA inlet duct suggestion raises another question, are they any useful benefit located in a low pressure area?

It's more about the local air velocity.The inlets decelerate the flow,while building static pressure,according to the (Daniel)Bernoulli Theorem.The are a ducted,diverging internal nozzle,fed by the kinetic energy of the oncoming flow just outside the inlet, designed specifically for this application.
Low pressure is associated with high velocity and visa versa,but they can't be in the 'shadow' of the body.Typically,they're in a portion of the body that is attacking the airstream regardless of their location on the body.Sloping nose or underbody,a bulging fender or quarter panel.The 2014 Corvette Sting Ray has a version of them atop the rear fender area exactly for brake cooling.