Project Help - Replicating Mc Laren's "F-duct"

[747heavy]

Sorry Rieker,
I don´t know the answer to your question, and I don´t want to give you a wrong information.
The obvious answer would be, the one which is closed to an F1 rear wing, but as I don´t know if there wing is based on any NACA profil, it´s a bit difficult to guess.
I don´t think that the flap profile as such will have a too great effect.

I think it`s more important to get the relationship between Flap and Mainplane right, and be as close as you can manage to the flow/load conditions of the whole assembly. If you see it as a "unit" (main pofile + flap) it may does not have much to do with a "wing" in the classical sense.
It´s pretty high camber and highly loaded, therefore very draggy.
If you look, the flap has allmost a 90° inclination to the main plane (it maybe is 75°) but nowhere near of a "normal wing"

Sorry, that I can´t help you with this one, but I´m sure there are others on here which maybe able to venture an educated guess.

[Carlos]

This is my favouite book on 'blown flaps' or more precisely; 'circulation control technology' - it's a collection of papers from the 2004 NASA Circulation Control Workshop.Your university may have a copy.If you absolutely can't find a copy, send a PM.

Applications of Circulation Control Technologies (Progress in Astronautics and Aeronautics) June 1, 2006 | ISBN: 1563477890 625 pages

[flynfrog]

You dont need to CNC cut your foam look at drop arm foam cutters I built one out of some scrap parts and a few things from the hardware store.

http://www.public.iastate.edu/~orman/ai ... twire.html

a dimer switch and a battery charger make a pretty good power supply for the wire.

[forty-two]

Looks like a very interesting project Riker.

You're not secretly a McLaren Mole planting here to find out how much the fans or indeed any team's engineers who visit this site happen to know about the operation of the F-Duct are you?

I think you would find the discussion in the following thread viewtopic.php?f=6&t=8028 very informative, especially some diagrams and animations put up by esteemed member "Ringo".

I know it's a gazillion pages, but I think you'll find some interesting analisys of both how the system "seems" to work, and how McLaren themselves have modified the system over the course of the year.

A good example of this is the original apparent curved slot which was used to begin with. This seemed to be dropped fairly quickly. Many would guess that it didn't work as well as a straight slot, but I personally wonder if McLaren abandoned the more technically elegant solution for one which was easier to machine and to get working properly.

Best of luck and don't forget to keep us posted. I for one would be very interested to know how you're getting along.

EDIT: Typo

[riker84]

Hello all,

Below is the rig i plan to assemble during this month. I have chosen two NACA profiles to give me the best downforce for the settings of my wind tunnel. The two profiles are a 23012 main plane, and a 23021 flap. I know these are not direct replicas of formula 1 wings, but as far as my machining capabilities go, they are the best option.

I am going to start doing some CFD this week, but am a bit lost as to what programme to use. I have 'Solidworks' and both ANSYS Workbench and ANSYS Classic at my disposal. Basically what I'm doing the CFD for is to try and anticipate some results.

Some pitfalls I have encountered is size of my airfoils, angle of blown air and the blockage effect. My univeristies wind tunnel is only 0.25m squared, I have yet to calculate my frontal area but I know by the dimensions I am going to have a problem. Also, the flap chord length is 25mm. This means for machining the inside of it out, I am going to considerably weaken the structure of the flap, which worries me.

Also, with regards the velocity of the blown air, what should it be with reference to the freestreams velocity. I saw that Ringo in other threads has used values of 1.5x and 2.0x. Is there any reason for this, or will it be trial and error?

As always, all help is greatly appreciated. With a special thanks to Carlos who sent me that fantastic NASA paper.
Best Regards,
Riker84


http://www.flickr.com/photos/33850204@N06/5421460982/


http://www.flickr.com/photos/33850204@N ... hotostream


http://flic.kr/p/9g5pqm

[Carlos]

These illustrations and photos might offer an impression of an F-Duct's size and characteristics:

http://www.racecar-engineering.com/tech ... echnology/
http://www.f1fanatic.co.uk/2010/04/16/f ... -practice/

[riker84]

Hello all,

Testing begins next week and I am having trouble calculating what the maximum flow rate through my air delivery device will be. The shape I have chosen is a teardrop, about 10mm tall, and 314mm long. I can use any pressure up to 3 bar from the colleges compressed lines.

I need to find the maximum flow rate so i can size up a flowmeter to connect to the college lines.
This is the shape I'm dealing with. Thank you