Harmonic excitation of the boundary layer.

[kilcoo316]

The Uni has wind tunnels but a lot of the course is CFD-based. I know there's a lot to choose from on that front. And I'm doing it at Glasgow University.

Do it in OpenFOAM.


You'll learn a lot more about the numerics and coding, and trust me, it'll stand to you if you ever want to go out as a consultant/contractor - as you can do the job with practically no overheads (in terms of licence fees).



edit: Is it a project or course based MSc?

[Scotracer]

The Uni has wind tunnels but a lot of the course is CFD-based. I know there's a lot to choose from on that front. And I'm doing it at Glasgow University.

Do it in OpenFOAM.


You'll learn a lot more about the numerics and coding, and trust me, it'll stand to you if you ever want to go out as a consultant/contractor - as you can do the job with practically no overheads (in terms of licence fees).



edit: Is it a project or course based MSc?

Thanks. I take it for Windows you want to download via "Other Platforms"?

It's a taught MSc with a project.

[kilcoo316]

Thanks. I take it for Windows you want to download via "Other Platforms"?

I haven't run it through windows, but I think "andlinux" can be used as an emulator for it.

It's a taught MSc with a project.

Ahh, ok. Enjoy!

[scarbs]

I think this might be beneficial on wing surfaces to reduce separation, allowing smaller more efficient slot gaps.

I also read an aircraft patent about heating the skin to reduce the BL viscosity. This was of interest, as the Boeing 787 has heated leading edge slats for ice protection, the upshot could be lower drag if they were turned on when it isn’t icy. Adding the heater mat within an F1 wings carbon plies would not be a structural challenge and the providing power to the mats will be easy through the mounting pylon. I ran this idea past some Mac aero guys who thought it was interesting, if not that beneficial.

[kilcoo316]

I think this might be beneficial on wing surfaces to reduce separation, allowing smaller more efficient slot gaps.

A laminar BL will increase separation, not reduce it...


Hence why they couldn't see a benefit of it (along with the absolutely negligible impact of BL drag* on the overall drag of an F1 car).

*especially the small bit that could be viewed as controllable.

[scarbs]

I think this might be beneficial on wing surfaces to reduce separation, allowing smaller more efficient slot gaps.

A laminar BL will increase separation, not reduce it...


Hence why they couldn't see a benefit of it (along with the absolutely negligible impact of BL drag* on the overall drag of an F1 car).

*especially the small bit that could be viewed as controllable.

That seems counter intuitive, but I accept your point. There still much in aero I need to learn

[Scotracer]

I think this might be beneficial on wing surfaces to reduce separation, allowing smaller more efficient slot gaps.

A laminar BL will increase separation, not reduce it...


Hence why they couldn't see a benefit of it (along with the absolutely negligible impact of BL drag* on the overall drag of an F1 car).

*especially the small bit that could be viewed as controllable.

Hence the use of Vortex generators?

[kilcoo316]

Hence the use of Vortex generators?

Exactly.


You wanna transfer the energy of the freestream down as far into to the viscous sublayer as possible.


A laminar boundary layer transfers energy through viscous effects alone, while a turbulent one will transfer through momentum exchanges as well.


You can see the difference in the energy levels when comparing the two boundary layer profiles (laminar and turbulent).

You can see the difference on higher energy levels in the sub-layer by the delayed separation of a turbulent boundary layer compared to a laminar one.





Hence why getting natural laminar flow onto aircraft is a right Thierry Henry (that means a right c*nt by the way). Cos the bloody flow ends up separating at take-off... even on nacelles... we'll get there eventually of course... although the matter of shock-induced separation is yet another bridge to cross...

[Balt23]

The topic you guys are discussing is (like a lot of things in F1) an active field of academic research. Boundary-layer control, transition mechanics, etc (though I'm sure many of you already know this!). Active Flow Control (AFC) can be used in a variety of ways depending on what you would like to do. A vibrating membrane or strip, at the right frequency, can have a positive effect on the flow. It doesn't do this by maintaining laminar flow, but by inputting energy at the correct frequency to create 2-Dimensional turbulent structures that end up having a better efficiency than if you were to naturally let a boundary layer move from transition to turbulence. Along with a vibrating membrane, you could also have acoustic excitation, excitation through harmonic blowing through a 2-D (span wise) slot, and even using plasma actuators to ionize the air the promote attachment.

A couple different places that I would see this helping but probably one of the most beneficial areas would be to prevent separation in the diffuser to increase efficiency and work around packaging constraints (with AFC separation control you could shorten the working length of the diffuser etc).

I also imagine that it might be too much work to get to work right for too little (overall) gain. With airplanes you can design it to work at a certain condition to boost efficiency (say, cruise) while with race cars, the conditions are much much more dynamic.