Sharkgills on toyota rearwing

bernard · Post 25 Jun 2004, 19:53

It's impossible to find good closeups of the toyota in jerez testing, but it has some kind of shark gills on the sides of the rearwing. Much the same as in sidepods. That is very strange. Explanations, anyone?

Monstrobolaxa · Post 25 Jun 2004, 20:31

It might be used to reduce the drag/vorticity caused by the rear wing.

CFDruss · Post 26 Jun 2004, 11:12

My assumption from looking at the position of them is they help control the vortex produced on the second element. But like all cutting edge F1 designs, you never truly know what the engineers have found unless they revel the secret, and we can only make assumptions based around knowledge and fundamentals of fluid mechanics

One way we could investigate, is if someone produces a CAD model, send it over, and we will run it in CFD

hehe, nice little tool CFD!!!! lol
If anyone is up for modelling it in CAD, make sure you do two models, one with no gills in the end plates, and one with gills in, so we can compare better. Send in either .Iges or .Step format would be good.

Russ

bernard · Post 26 Jun 2004, 15:43

Which program would be good for making cad models? I've only modelled using 3ds max, and it's not capable of producing the formats you mentioned.

Monstrobolaxa · Post 26 Jun 2004, 17:12

CATIA, Unigraphics, Solid Works...

Guest · Post 26 Jun 2004, 18:11

Why cant it be something simple as an attachement point for the rear wing elements ?

/ Fx

Spencifer_Murphy · Post 26 Jun 2004, 19:14

The gills are Toyotas interpretation of a tried and tested Idea. Remember last year some teams (Including toyota) ran a rearwing endplate with a small triangular cut-out on the top edge, just in front of the final element? The idea is to encourage more air to flow across this gap and onto the rear wing allowing higher wing angles due to a decrease in the stalling speed of the wing. (Because more air is flowing over it). These sharks gills work in the same way.

bernard · Post 26 Jun 2004, 20:30

The idea is to encourage more air to flow across this gap and onto the rear wing allowing higher wing angles due to a decrease in the stalling speed of the wing.

Good point, but if this is the case, then wouldn't it make sense to make the gills vertical rather than horizontal as they now are? At the moment they don't allow much air to pass through...

Monstrobolaxa · Post 26 Jun 2004, 21:17

Thinking about what was previously posted....air flow flows from high pressures (low speed) to lower pressures (high speed). In this case the air circulating on the out side of the end plates is circulating faster then the air the is being used to create downforce....so there will be the tendency for the air to flow from the wing to the outside of the endplate...and not the other way around.

CFDruss · Post 27 Jun 2004, 03:59

Hi Monstrobolaxa

Dont really get what you have posted there, explain more. Yes low pressure flows to high pressure, but the speed of the air outside the end plate will not be as fast as the speed of the low pressure side of the wing!!!

Russ

Monstrobolaxa · Post 27 Jun 2004, 04:19

The thing is....having a wing the air flowing around the outside of the endplate will be flowing faster then the air that is going between the endplates (the air between the endplates will create the downforce).

The thing is since the air flowing on the outside of the end plates is faster it's pressure will be lower....the air in contact with the wing will have a higher pressure and will be slower....this means that the air flow will be flowing from the inside of the endplates (wing) to the outside.

What Spensifer says in his post seems to be the oposite to what me and you (Russ) said in the first posts.

eweturn · Post 27 Jun 2004, 09:48

This is a link to a closer look of the end.plates ://www.f1racing.net/en/photolarge.php?phot ... catID=1408

Toyota ran these gills in the US, however onlt with two slits. They also seemed be a little higher on the end plate as well. At Monaco they ran the three slit configuration, so there maybe a disandvantage at lower downforce circuits? US http://www.f1racing.net/en/photolarge.p ... D=269-1105 Manoaco http://www.f1racing.net/en/photolarge.p ... ID=93-1105

Bernard, there are flipups and the rear wheel which would influence the direction of the airflow. It may be more vertical than the horizontal??

S_Murphy, looking at the shape of the gills I would say that they would be trying to promote a flow from within the wing area to outside the endplate.

Monstrobolaxa, the gills are on the side of the wing that would have the higher pressure and in the most part forward of the wing element. I would then think that without specific figures, it would be hard to state which airflow would be faster, especially given all the other parts of the body work outside the endplates that would influence the airflow (ie the flipups, mid-wings, chimneys and shark gill on the engine covers).

What I am more suprised about is that no one has mentioned the Renaults rear wing. It is hard to find a good shot, but they seem to use a single slit that is much wider, starting approx 1/4 of the way along the endplate and never reattaches. The upper element also seems to end at approx 2/3 the length of the endplate. This seems alittle strange as they are not maximising the surface area available, thus downforce. Obviosuly it has other advantages. http://www.f1racing.net/en/photolarge.p ... &catID=105 http://speed.supercars.net/IMG?viewPic= ... ault&o=R24

On another subject, did anyone else notice the shark gills on the Renaults chimney http://www.f1racing.net/en/photolarge.p ... D=268-1101

West · Post 27 Jun 2004, 11:26

I just heard they reduce drag, if not create downforce.

Monstrobolaxa · Post 27 Jun 2004, 14:30

eweturn wrote:I would then think that without specific figures, it would be hard to state which airflow would be faster, especially given all the other parts of the body work outside the endplates that would influence the airflow (ie the flipups, mid-wings, chimneys and shark gill on the engine covers).

It's quite easy to see that the air flowing on the outside of the endplates flows faster then the air in between the endplates and being in contact with the wing! an example...if you stick your hand out side the window which air circulates faster? the air "hitting" hand? or the air going around your hand? Same thing here the air that is circulating outside the endplates circulates faster. About the distubance....the air box probably creates more turbulence to the rear wing the the flip-ups, chimneys, etc create to the airflow circulating on the out side of the endplates.

Monstrobolaxa · Post 27 Jun 2004, 14:41

Just remembered...if you look at the CFD images Stik published that are in one of the threads

viewtopic.php?t=285&postdays=0&postorder=asc&start=15

look at the third image:

if you look at the pressure of the undisturbed airflow infront of the wing the pressure is around 100971 Pa if you consider the undisturbed airflow around the wing to be at the same pressure (for the same conditions as the ones in Stik's images) it will have the same pressure. now comparing the pressure on the wing with the pressure around the endplate....still looking at this picture (3rd) you'll see that the pressure on the wing in the region where Toyota has the gills , is around: 102557 Pa. If you compare both pressures you'll see the pressure on the inside is higher then the pressure on the outside....so air will tend to flow from the wing to the outside....that is why vortexs are created at the tip of the rear wing...due to pressure diferences from the inside to the outside (of the endplate).

To me those "gills" have the intention of reducing the pressure diference from the inside to the outside (of the endplates) in order to recuse the vortexs...which will lead to a reduction o pressure drag.