F1 slow mo

[RB Will]

Sorry if this is a repost.
Its interesting to see how bendy the cars actually are.
http://www.dpccars.com/car-videos-09/07-17-09page-...

[paulrockliffe]

That remind me, I thought there were rules about movable aero devices?

[Nick M]

Seen very brief clips of slo-mo footage, but great to see a slightly longer compilation like that.

Does make you wonder about all the work done in wind tunnels and why sometimes the results don't translate into results on the track - I imagine a lot of hard work could be undone if a component flexes in an unexpected way.

Also wonder if all the CFD they do is able to model the effects of components flexing like that. I guess they must be able to get some data off the simulator rigs, but I doubt that's quite the same as there's no airflow over the cars to match the downforce.

Fascinating stuff though !

[jazz.cat]

Nick M said:

Does make you wonder about all the work done in wind tunnels and why sometimes the results don't translate into results on the track - I imagine a lot of hard work could be undone if a component flexes in an unexpected way.

That's why they left Lewis out for the whole race in Germany. Lots of in-race data to be gained.

[paulrockliffe]

There's no way they can do maths that take into account components flexing like that. Seeing it made me think that maybe the aero in a straight line was much more important compared with the aero round a corner than I thought.

[Nick M]

paulrockliffe said:

There's no way they can do maths that take into account components flexing like that. Seeing it made me think that maybe the aero in a straight line was much more important compared with the aero round a corner than I thought.

I think you're probably right, but given what has been written about teams doing 'modelling' with the tyres and how they deflect and affect aerodynamics, I'd be surprised if there wasn't *some* account taken of flexing components and how that affects airflow. Looking at those pictures it would seem to be a fairly important issue with the scope for airflow to become detached at unexpected moments.

[_dobbo_]

Not sure they need to take into account the flexing when modelling, it all happens for a fraction of a second and at that point the aero and grip are already compromised by the impact with the kerbs.

[navier_stokes]

Nick M said:

paulrockliffe said:

There's no way they can do maths that take into account components flexing like that. Seeing it made me think that maybe the aero in a straight line was much more important compared with the aero round a corner than I thought.

I think you're probably right, but given what has been written about teams doing 'modelling' with the tyres and how they deflect and affect aerodynamics, I'd be surprised if there wasn't *some* account taken of flexing components and how that affects airflow. Looking at those pictures it would seem to be a fairly important issue with the scope for airflow to become detached at unexpected moments.

The maths for this kind of dynamic modelling is readily available - see coupled FEA and CFD. However the computational cost needed is far more than the F1 teams have available, given the build time scales they work with. Also, most F1 teams use commercially available RANS CFD which is not really going to be able to resolve that sort of (transient) flow accurately (again given the time scales required). I'm sure they do some basic transient modelling and steady modeling with the parts pre-flexed as they would be under load though.

You can't model it in the wind tunnel either because even though the model and air speeds are dynamically scaled to match the equivalent real scale Reynolds number, the wind tunnel model components are not structurally dynamically scaled to match the real scale structures.

This kind of flexing will definitely alter the aerodynamic loads but the big kerbs are usually on the slower corners where the scale of the loads are low.

[egomeister]

paulrockliffe said:

There's no way they can do maths that take into account components flexing like that. Seeing it made me think that maybe the aero in a straight line was much more important compared with the aero round a corner than I thought.

It's a balancing act, but aero in cornering is more important. Downforce is not much used to you in a straight line.

I was amazed at how much the toyota winglet moved, and I expect the guys at toyota would be too!

[mchammer89]

Is it just me or were the Red Bull & Torro Rosso cars flexing much more than the rest? And it was great to see that flat spot happening in slow motion too!

[sniff diesel]

paulrockliffe said:

That remind me, I thought there were rules about movable aero devices?

Funnily enough the Ferraris seem to have the least flexing wings out of those shots.

[Marcia]

The Toyota looked the most flexible.

[mchammer89]

Marcia said:

The Toyota looked the most flexible.

Yeah but there's no advantage (to my eyes at least) of that little winglet flapping around so much, if they wanted it close to the main part of the side of the wing they would've made it like that, there's no rules governing that, as if anything that movement will just cause slightly more instability as the air is gonna be alternating between going faster and slower. With the rear wings there was an obvious advantage as the wing angle became steeper under braking providing more drag and downforce.

[mchammer89]

sniff diesel said:

paulrockliffe said:

That remind me, I thought there were rules about movable aero devices?

Funnily enough the Ferraris seem to have the least flexing wings out of those shots.

So maybe it was Ross Brawn behind all the dodgy technology *dons tin foil hat*