CW Racing
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I just had time to look At the results of 'Craig's end plates' this morning. Looks to have split the difference on the downforce numbers but I will go through it maybe tonight.
Numbers is about 460N so so ever the wing with no end plates it produces about 8.6% more down force with small end plates and 21% more downforce with the big ones on. Obviously this needs refining to suit the car to retain as much of this as possible.
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I now have the wing with small end plates (we will call them Craig's end plates.) running at the moment. I have reduced the detail as it was taking 12 hours to solve each one.
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i use ansys and floworks/cosmos...
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im working on that... i have a summery to post on this to finish the general principals bit of what end plated do then im going to try and put a car shaped blob in front of the wing
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So everyone…. Welcome to part 2 of my aero class lol…
I finally managed to get around to finishing my study with the wing and its end plates in place…
Again this is exactly the same wing but with end plates added as the design of our le mans car. The air flow is as 30m/s as before.
We have left the scales of the pressure plots and the flow lines the same so there is a good comparison.
Picture 1
top view with pressure plot
Picture 2
lower view with pressure plots
Picture 3
top view with flow lines
Picture 4
lower view with flow lines
the results are for this wing a downforce number of 527N (52Kg) with drag force of 86N (8Kg) so it has a L/D of 6.12 so thumbs up!!!!!
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Chip in anyone with any questions or opinions on what we are on about.
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Yep that looks like a scooby wing. Idea of these is to try and straighten the car when it jumps. You see it more on rally cars and Dakar trucks. We did it on the Nissan we built some years ago. I will try to find some pictures.
The idea with a swept wing on an aeroplane is because you get 'flow migration' across its length, due to the angle you put these ribs or flow straighteners in place to limmited the effect.
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Are you talking about the little flicks on the wing tips??
That fact you dont see winglets as you call them on race card isn't because they havnt experimented with them. It's usually because of regulations. Our le mans regs say there must be a vertical end plate of a given surface area when viewed from the side and it leading edge be radiused 5mm rads all round. And be parallel in section through its body.
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So I would agree with that statement. The high rise arrangement is the shape it is because the low spoiler is the shape it is. One has to lead into the other. Not to say it isn better though.
Notice how the TRD spoiler is a parallel section that is adjustable.
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so here is another wing with the flow comming in at an angle. you can see if the end plate is to big it blocks the wing. big areas of turbulant flow
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i have a small simulation running on my laptop to show the wing in yaw. this will be very rough but it shows the principal well,
my big pc is still plugging away on the other sim
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Jamie but is that not because your running without end plates and so the air gets lost over the edges and doesn't 'push' down as it will take the easiest route. In the centre of the spoiler it doesn't really have this choice....
why yes craig that is correct.... now the art is to tailor the plates to best exploit the shape of the body infront and how when the car is in yaw how that blanks and stalls the wing
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so i have circled the ends of the wing.... you can see in these regions that the colours are different which signifies a difference in pressure. as you can see the colour is orange towards the ends on the top and there are flashes of yellow on the corresponding underside... these colours are much closer together on the colour spectrum than the extremes of red and blue... this shows that the ends of the wing is not producing as much downforce at the middle section of the wing.....
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well then that would be perfect then
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So would getting a [real/tested] high rise spoiler help ? I'm already thinking of getting a Kamimari spoiler and will consider it even more if it's going to help improve aero balance
yeah it wouldnt hurt... typically with a saloon car style vehicle you have the big weight on the front to mechanically aid the front tyres grip but you have little weight on the rear so less mechanical grip. bare in mind though you only get aero effects thats noticable from about 40mph up so spoilers etc are more for show on your road car unless you make the odd excursion to the track.
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you need to get the aero balance in sync or similar to the weight balance typically to get the car to handle
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Sorry I don't have much of a grasp on aero/downforce etc. but i'm thinking the more you push the back of the car into the road, it's going to ever so slightly start lifting the front, thus reducing actual steering grip ?
or does it not work like that ?
kind of... that called aero balance but saloon cars are so biased fwd its unreal....
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Why would you wanna push down the rear of a FWD car?
P.s. Loving your job I love seeing pics of cars/F1's in wind tunnels etc if you've got any websites with loads of pics like that please let me know
Trust me at high speed in a fwd car that's stripped out the back will come round on you. I've put mine into a power slide a few times at about 80mph
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so the forces produced by this wing at 30m/s are as follows 420N of downforce to 80N of drag.... thats an L/D ratio of 5.25 (higher the number the better)
so thats 42kgs of pressure on the rear of the car
I'm not a geek when it comes to Aero's but seeing this does get me thinking about Aero's on my Gen7.
When i was at RT-P i did mention to Ray about making a cheese wedge to sit under the posts on the rear spoiler to add some more angle to it, and in theory more surface resistance area resulting in pushing the arse end down.
I know that we dont own super cars that need Aero's to keep them on the road, but surly adding a little will aid us mere mortals when giving our babies the beans on country road corners.
sketch something up and i will pass on some comments and suggestions....
there is a few more bits to point out on this first but the next simulation is currently running with the le mans end plates on to show how these aid the downforce generation
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So as part of my job on the le mans team im asked my opinion on some aero bits and bobs. i also have access to some cfd software and Craig and myself have been talking about rear wings and endplates in particular.
i havnt got a model of any of the wings on our cars or a model of a celica but i have got models of out le mans car wing so i thought i would play around with that...
it is a two element wing with a mandetory gurney flap on the trailing edge.
i ran a simulation of the wing in free air flow (No car body in front) to get a pure assesment of what the wing does at an air speed of 30m/s (67mph) with out any end plates.
here are the screen shots:
Picture1
Top view of the wing with surface pressures
Picture 2
underside view with surface pressures
Picture 3
top view with flow lines
Picture 4
Underside with flowlines
Picture 5
section with flowlines
im off to make my tea but will be back later with some more on what im looking into
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Nice. Bet your relieved.
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yes.... mostly in car..... search 'msportclare' on you tube
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Just a quick one to say thankyou to a few members that have helped me out over the last few weeks,
Mondo, thanks for the coilovers and releasing them to me before i have paid them off.
Briano, thanks for binging the coilovers to a place a could collect them from.
Nix, thanks for holding them until i could get over and collect, as well as provide me with my project engine for my race car.
THANK YOU!!!!!!
Bit of Aero for those who like that sort of thing PART 3
in General Celica Discussion
Posted
I keep chipping away at this as and when i get 5 mins to myself..
been reading back what i have said and to clear up one thing... im only measuring the forces that the wing elements them selves give... not the wing and the end plates together as we are looking at how adding things to the wing affects how the wing planes become better or worse at producing downforce and obviously try to quantify this with some numbers..