Ferrari F138

[turbof1]

My opinion is that air behind the sidepod bulge is of lower speed, detaching from the sidepod and having serious boundary layer issues. That's going to result in extra drag, more influence around the exhaust area, and less accelerated airflow through the vanes on top of the diffuser. I also believe that is why they are having problems figuring out which of the 2 sidepod configuration is the better: the longer one injects the exhaust gasses more accurately, but worsens all other problems, the shorter one vice versa.

You can try to fix that and indeed ferrari heavily tries to do so, curling the floor at key locations and making time after time alterations to the sidepod turning vane. If you can do that right you can steer airflow and energise it well enough to keep it attached and at a high enough speed. The issue ferrari is having is that it is very difficult to get this done and is an artwork of aero detailing, something near impossible to do when you have windtunnel problems.

[marcush.]

My opinion is that air behind the sidepod bulge is of lower speed, detaching from the sidepod and having serious boundary layer issues. That's going to result in extra drag, more influence around the exhaust area, and less accelerated airflow through the vanes on top of the diffuser. I also believe that is why they are having problems figuring out which of the 2 sidepod configuration is the better: the longer one injects the exhaust gasses more accurately, but worsens all other problems, the shorter one vice versa.

You can try to fix that and indeed ferrari heavily tries to do so, curling the floor at key locations and making time after time alterations to the sidepod turning vane. If you can do that right you can steer airflow and energise it well enough to keep it attached and at a high enough speed. The issue ferrari is having is that it is very difficult to get this done and is an artwork of aero detailing, something near impossible to do when you have windtunnel problems.

is it even possible to test exhaust effects in the windtunnel
?
I ´d assume introducing 800KW of Exhaustheat into a windtunnel for any period of time will influence your experiment just too much ...or do they have that much cooling capacity to be able to maintain constant temps in the tunnel?

[turbof1]

Thomba made an excellent piece about that:

It's been well documented that the Coanda exhaust is difficult to simulate in a windtunnel, as the flow is generated by the engine, acting as a very powerful air pump pushing out hot gases. Pumping air through pipes within the wind tunnel model is difficult enough already, leaving alone that this air needs to be heated. If you consider that F1 wind tunnels are all closed circuit systems, a hot exhaust flow would increase overall air temperature within the tunnel very soon, making further tests impossible until the tunnel is cooled down again.

Of course, if you on top of that have correlation problems you are better off not trying it at all.

[type056]

Alonso on Ferrari trction problem in Abu Dhabi :

" The traction problems are not due to the mechanical side, but on the aerodynamics.

"It is up to the aerodynamics. Whenever we test small aerodynamic parts, then the car changed completely. I guess that's why we do not have optimal traction," says Alonso. Massa reports of the same difficulties: "On this track, the traction is very important, it makes a big difference This is a long-time problem of our car It depends on the route on whether we have more trouble..."

I thought that main problem for for low traction was mechanical (grip) not aerodynamics because there is little aero downforce when car goes out of slow corner.

I am confused by Alonso comment.can you explain it?

Sorry for my bad English.

[AnthonyG]

Thomba made an excellent piece about that:

It's been well documented that the Coanda exhaust is difficult to simulate in a windtunnel, as the flow is generated by the engine, acting as a very powerful air pump pushing out hot gases. Pumping air through pipes within the wind tunnel model is difficult enough already, leaving alone that this air needs to be heated. If you consider that F1 wind tunnels are all closed circuit systems, a hot exhaust flow would increase overall air temperature within the tunnel very soon, making further tests impossible until the tunnel is cooled down again.

Of course, if you on top of that have correlation problems you are better off not trying it at all.

Why don't they test it in real life? They can use a paraffin oil injector rigged into the exhaust to make it visible.

Of course they should do it during a private test because I don't think the FIA wants the track covered in smoke during friday free practice.

[timbo]

Wonder if they can go Williams route and try the car without coanda exhausts. Though too little time left.

[theWPTformula]

Thomba made an excellent piece about that:

It's been well documented that the Coanda exhaust is difficult to simulate in a windtunnel, as the flow is generated by the engine, acting as a very powerful air pump pushing out hot gases. Pumping air through pipes within the wind tunnel model is difficult enough already, leaving alone that this air needs to be heated. If you consider that F1 wind tunnels are all closed circuit systems, a hot exhaust flow would increase overall air temperature within the tunnel very soon, making further tests impossible until the tunnel is cooled down again.

Of course, if you on top of that have correlation problems you are better off not trying it at all.

Why don't they test it in real life? They can use a paraffin oil injector rigged into the exhaust to make it visible.
http://s1.cdn.autoevolution.com/images/ ... wood_2.jpg
Of course they should do it during a private test because I don't think the FIA wants the track covered in smoke during friday free practice.

Interesting idea! What they currently do is place flo-vis on the floor area and see how the exhaust gases are influencing the floor in that region. Ferrari conducted these tests and opted to trial the elongated sidepods during mid-season, bring the exhaust exit closer to the floor.

McLaren ran some interesting sensors during the YDT at Silverstone. They covered the rear of the floor in some sort of heat-sensitive blue paint and also lined the floor with rows of sensors. (You can see the blue paint in this image - http://www.f1passion.it/wp-content/uplo ... 36x291.jpg)

[Crucial_Xtreme]

GA says Ferrari modified the brake disc size in India..


via AutoSport


And an article on correlation and Ferrari


via AutoSport

[Crucial_Xtreme]

Seems it went unnoticed by us and everyone else, but Ferrari modified the RWEP extensions in number length & shape.

Japan- 8 RWEP slats


India- 8 RWEP slats(team used 9 slats in India but flo-vis tested 8 slat version pictured below. I'm unsure which was used in GP Link )



AD- 9 RWEP slats




Edit: Nice flo-vis image from AD free practice

[emmepi27]

Good spot Crucial! But new endplate's lower profile come already from India!
I made this comparision. The newest is too similar to the Red Bull

[Crucial_Xtreme]

Good spot Crucial! But new endplate's lower profile come already from India!
I made this comparision. The newest is too similar to the Red Bull

I didn't notice the lower profile in India, but I did this evening which got me counting the number of slats. Too bad it's not helping the car much. :/

[emmepi27]

Good spot Crucial! But new endplate's lower profile come already from India!
I made this comparision. The newest is too similar to the Red Bull

I didn't notice the lower profile in India, but I did this evening which got me counting the number of slats. Too bad it's not helping the car much. :/

Me too! But Stefan posted it! So, i'm going to check if they have used it yesterday
http://i.imgur.com/XjW8AOH.jpg

[Crucial_Xtreme]

Ohhh ohhh, those flow viz traces don't look really well. Seems the flow around the coke bottle completely detaches. There appears to be a complete stagnation area underneath the exhaust / cooling air outlet area.
Probably too much obstruction from the huge hot air exhaust combined with too agressive waist due to the vertical coolers causing too high of an adverse pressure gradient. The result will be no significant flow to the whole upper side of the center section of the diffuser and thus loss of a lot of Diffuser efficiency/effectiveness. If this was not a one off due to specififc circumstances I start to feel they have a massive problem in that area. This would also explain why the car doesn't seem to react to the different versions of the exhausts. Exhaust blowing itself might simply not be their main problem.

In regards to the Ferrari flo-vis picture in question, I and Scarbs asked a current F1 Aerodynamicist about what he thought regarding the results..

I asked Aero_A about the Ferrari Flo-Vis and his response to the flo-vis results on the F138 in AD were:

Link
"pretty clean, potentially a tiny bit of separation at the floor bodywork junction max width but nice otherwise."

And in another convo where Scarbs asked Aero_A if the low louvered cooling section be upsetting things, he replied:

"potentially but the crap looking bit around there is just due to a step in the panel as opposed to the lovers."
Link

[henra]

Link
"pretty clean, potentially a tiny bit of separation at the floor bodywork junction max width but nice otherwise."

Hmmm, intersting!
The flow straight back looks indeed clean, but what irritated me was that there seemed to be no flow following the coke bottle. All flow seemed to be going straight back. That is why I concluded there was separation occuring or a boundary layer opening up way too much.
Did he make any comment in that regard?

[Crucial_Xtreme]

Hmmm, intersting!
The flow straight back looks indeed clean, but what irritated me was that there seemed to be no flow following the coke bottle. All flow seemed to be going straight back. That is why I concluded there was separation occuring or a boundary layer opening up way too much.
Did he make any comment in that regard?

He didn't but I will ask.