he wasn't talking about the duration. And most racetracks aren't just a straight line.
he wasn't talking about the duration. And most racetracks aren't just a straight line.
it's the same lol...
Slipstream is baisically moving air, and a pressure difference.
And if the "intensity" is higher, the cars which are lets say 20m aways will also get more slipstream.
But like sinbad said: Simulating those streams is highly complicated and only possible with very ineffective numerical mathematics nowadays (iterations), so it's impossible to simulate correct airflow at a acceptable accuracy in realtime.
Im sure those shots there from the F1 cars took some hours to "render"
And it's also difficult to measure the correct values, because 1. the forces are rather small, and piezo-elements might not be exact enough (not really sure though, as I dont have one ), and 2. because Scawen has no race car and no racetrack 
Slipstream is baisically moving air, and a pressure difference.
And if the "intensity" is higher, the cars which are lets say 20m aways will also get more slipstream.
But like sinbad said: Simulating those streams is highly complicated and only possible with very ineffective numerical mathematics nowadays (iterations), so it's impossible to simulate correct airflow at a acceptable accuracy in realtime.
Im sure those shots there from the F1 cars took some hours to "render"
And it's also difficult to measure the correct values, because 1. the forces are rather small, and piezo-elements might not be exact enough (not really sure though, as I dont have one
), and 2. because Scawen has no race car and no racetrack What I ment when I said they're not neccessarily the same is that the model which is used to calculate the effect in LFS probably has several parameters which are not tightly correlated (in contrast to real life where there's "absolute" correlation because it's actual physics).
I.e. the model might work like this:
- for car X the there exist a slipstream effect in <deg> degrees angle behind the car with <max> effect right behind it degrading over distance as a function of 1/distance calculated for upto <dist> meters behind it, etc. There could be more parameters that use the movement vector of the car, the orientation of the car towards the movement vector etc.
So, in that model, you could change either <max> or the function (replacing 1/distance with something else, or even a precalculated table) and in both cases you'll have different effect. Of course, if you change the max effect, it *might* effect the distance in a model. But it comes down to the model used.
I.e. the model might work like this:
- for car X the there exist a slipstream effect in <deg> degrees angle behind the car with <max> effect right behind it degrading over distance as a function of 1/distance calculated for upto <dist> meters behind it, etc. There could be more parameters that use the movement vector of the car, the orientation of the car towards the movement vector etc.
So, in that model, you could change either <max> or the function (replacing 1/distance with something else, or even a precalculated table) and in both cases you'll have different effect. Of course, if you change the max effect, it *might* effect the distance in a model. But it comes down to the model used.
Didn't read all posts (sorry) but there are some things I find hard to comment (but I still do) regarding the aero effects.
1) dirty air behind the cars. This is not directly a problem whether the LFS simulates this correct or not. It's more about the aerodynamics properties the LFS cars are meant have. (how the rear end of the car creates dirty air and how the front wing uses it). Though the high nose gain is a "bug".
2)I have no real life racing experience (like most of you too) so it's impossible to comment this. But I still try. The slipstream force seems to be too big. In F1 couple of years ago there was less dirty air and more slipstream. But it still took a long straight to even get aside with equal car. In LFS, like in ovals this gets odd measures as the cars with little downforce pass others all the time (though the high speeds compensate little for the smaller downforce)
3) The car in front should also gain some more speed. Don't know does it.
4) Currently driving in the slipstream makes the car much more loose on the rear. I thought in F1 they can't drive close because the front wing loses the airflow and therefore the downforce gets smaller in front. So the car pushes as a result. Though under braking this is currently right(ish), but still the rear get more happy than front. Maybe because more oversteery aero setup, but...
Just my 4 cents
1) dirty air behind the cars. This is not directly a problem whether the LFS simulates this correct or not. It's more about the aerodynamics properties the LFS cars are meant have. (how the rear end of the car creates dirty air and how the front wing uses it). Though the high nose gain is a "bug".
2)I have no real life racing experience (like most of you too) so it's impossible to comment this. But I still try
. The slipstream force seems to be too big. In F1 couple of years ago there was less dirty air and more slipstream. But it still took a long straight to even get aside with equal car. In LFS, like in ovals this gets odd measures as the cars with little downforce pass others all the time (though the high speeds compensate little for the smaller downforce)3) The car in front should also gain some more speed. Don't know does it.
4) Currently driving in the slipstream makes the car much more loose on the rear. I thought in F1 they can't drive close because the front wing loses the airflow and therefore the downforce gets smaller in front. So the car pushes as a result. Though under braking this is currently right(ish), but still the rear get more happy than front. Maybe because more oversteery aero setup, but...
Just my 4 cents
Ok, I've just driven some FOX @ BL1 and the current downforce/slipstream model is really starting to piss me off :mad:
As soon as you enter the slipstream there's suddenly no more downforce at the rear... which isn't exactly what I need when I'm cornering at 160km/h...
As soon as you enter the slipstream there's suddenly no more downforce at the rear... which isn't exactly what I need when I'm cornering at 160km/h...
Well that aspect of it is fairly realistic, just needs to be toned down a hair..or clump of hair
Well, emphasis was on the NO more downforce. The problem is that front and back wing suffer equally from downforce loss, but it should mostly be the front one only. Which would have a vastly different result.
I saw a document about Sennas accident and it was said that ground effect is very strong when driving straight line and while cornering. But it was also said that if your rear end just slides even a little bit you suddenly loose all ground effect. And in Senna's case he lost the ground effect and had no way of recovering from it (not my opinion, it was said in the document. It's long time since I saw it so I may remember it wrong. And there is the theory of broken steering axle, or something, too).
But no downforce (just ground effect) in F1 is a suggestion that I can't take seriously. Like putting a manual clutch in F1...
Maybe someone make a test: make a very low-front-aero setup for the F08 and drive behind an F08 with very low-rear-aero setup. How do the forces change when the distance gets smaller? And has the front runner any gain in speed when the other is only 1 inch from him?
EDIT. Added a link to site offering some info about the downforce: http://www.nas.nasa.gov/About/Education/Racecar/
No, I think currently only the drafters get a speed boost.
I know.... dissapoints me that some good drivers can setup a situation where you spin out or lose it JUST to have them get you off their arse (or so you lose and they win, obviously).... really stupid tactics by exploiting a bug in the game :chairs:
has anybody tried putting the fo8 into a cfd tool yet to simulate the hell out of it until we have some realistic values for how long and strong the trail should be ?
About Senna's crash documentary - I downloaded it the other day. It's totally correct, but one solution is to make the use of magnesium skid blocks at certain points, so the actual floor can never touch the floor, and hence ground effect isn't lost easily.
And it has the positive side effect of the dramatic sparks returning to F1, rather than saw dust :S
And it has the positive side effect of the dramatic sparks returning to F1, rather than saw dust :S
EPS race on monday...I was slipstreaming Jay on the main straight of SO4, pulled out of his slipstream to pass him - and almost spun Oo
This is in no way realistic, since the rear wing is affected much too much atm -.-
This is in no way realistic, since the rear wing is affected much too much atm -.-
Well, you need a CFD tool, exact model of the F08 in right file format and person to understand the results. I guess we need someone to make the 3d model first and then someone willing to spend lots of time. And I don't know how exact the results would be...
And I don't even think the 3d model we see have actually anything to do with aero effects coded in game. That is not a bad thing as it is impossible to simulate 3d model's aero effects real time. As far as I can tell it is just a good guess.
they should have a lot to do with the forces in game ... of course not in the sense of a real time cfd but in the sense that the aero model applied to the car should simulate the aerodynamic properties of the cars body as we see it in game as closely as possible
Only if Scawen has access to CFD, which I doubt. Most likely he's using very rough approximations based on 'facts' he read somewhere. It might be quite close, but it might just be a simple case of
slipstream length = speed^2 * Cd
or something equally easy.
If I had the time I'd look at importing the cars into CFD at uni, but time to do projects like that is not going to be easy to find... It's hard enough doing 2D problems :S
slipstream length = speed^2 * Cd
or something equally easy.
If I had the time I'd look at importing the cars into CFD at uni, but time to do projects like that is not going to be easy to find... It's hard enough doing 2D problems :S
Well first the devs just decide what kind of car they are going to have...
I think Eric has just made the models looking at the F3000 and such to have some equal characteristics in them. At the same time Scawen has been researching the aero data about different kinds of formula cars (similar in power and layout) and then the devs just decide what is the real life counterpart(s) of the F08 for example and how they react. Then they probably just try to take the most useful data out of it. But finding this data must be extremely hard, maybe we need some Gp2 organization to sponsor LFS by providing some info about the car and physics related.
Well that kind of stuff needs a lot of expertise as even the simplest structural analysises I have made need a lot thought before they can be used.
OT: BTW. tristan (or anyone), you study mechanical engineering in UK...might you have any downloadable PDFs or stuff about anything automotive related designing? What I'd like to have is some studying material they give you at school. I understand if you don't want to give me anything as I guess university education is expensive in UK (?) and therefore you've paid for the material. In Finland it's free . I really wouldn't like to buy any expensive books about it and at my uni there isn't really anything automotive related courses.
I think Eric has just made the models looking at the F3000 and such to have some equal characteristics in them. At the same time Scawen has been researching the aero data about different kinds of formula cars (similar in power and layout) and then the devs just decide what is the real life counterpart(s) of the F08 for example and how they react. Then they probably just try to take the most useful data out of it. But finding this data must be extremely hard, maybe we need some Gp2 organization to sponsor LFS by providing some info about the car and physics related.
Well that kind of stuff needs a lot of expertise as even the simplest structural analysises I have made need a lot thought before they can be used.
OT: BTW. tristan (or anyone), you study mechanical engineering in UK...might you have any downloadable PDFs or stuff about anything automotive related designing? What I'd like to have is some studying material they give you at school. I understand if you don't want to give me anything as I guess university education is expensive in UK (?) and therefore you've paid for the material
. In Finland it's free . I really wouldn't like to buy any expensive books about it and at my uni there isn't really anything automotive related courses.All I know is that the draft in the FO8 is way too 'potent'. The physical size of the slipstream is actually pretty spot on but the burst of speed the trailing driver gets from it is way too much.
I haven't raced on the oval in ages because its all about the draft. You are royally screwed without the draft. I watch real-life Indy car racing on high speed ovals and a fast car with a good setup IS capable of gaining on a group because the draft just does not produce that slingshot effect with such low-downforce wings.
I haven't raced on the oval in ages because its all about the draft. You are royally screwed without the draft. I watch real-life Indy car racing on high speed ovals and a fast car with a good setup IS capable of gaining on a group because the draft just does not produce that slingshot effect with such low-downforce wings.
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