Williams FW33

[boyracer94]

say a maybe wing?

Interesting... you could be on to something here.

What about engine exhaust? They could also choose to blow the beam wing.

Blowing the beam wing would create a low pressure zone below the wing, on top of the diffuser no? Surely that would decrease the efficiency of the diffuser?
Correct me if I'm wrong, I'm here to learn

[adrianjordan]

Blowing the beam wing would create a low pressure zone below the wing, on top of the diffuser no? Surely that would decrease the efficiency of the diffuser?
Correct me if I'm wrong, I'm here to learn

I think it would depend on exactly where the low pressure was located. If it was on top of the diffuser, then I think you could be right. However if they could somehow get it to work such that the low pressure interacted with the diffuser to draw more air through it, then this could theoretically increase the efficiency of the diffuser and increase downforce. Or I could be talking a load of codswallops (wouldn't be the first time)...!!

[Just_a_fan]

say a maybe wing?

Interesting... you could be on to something here.

What about engine exhaust? They could also choose to blow the beam wing.

Blowing the beam wing would create a low pressure zone below the wing, on top of the diffuser no? Surely that would decrease the efficiency of the diffuser?
Correct me if I'm wrong, I'm here to learn

The diffuser's job is to get the airflow below the floor to match the airflow behind the car. If the air immediately behind the car is at a lower pressure (e.g. a 'bubble' attached to the beam wing) then the diffuser effectively has to do less work which means it's more likely to be efficient. It's also more able to flow more mass of air through the floor which will improve overall downforce.

[Halgovern]

I always thought the diffuser accelerated the air out of the car? If its job is to match the speed of airflow under the car to that of the flow behind the car, how does it produce downforce? Can someone explain please

[horse]

I think describing the diffuser as matching the airflow is a little confusing. I think it's easier to think of the diffuser as giving the floor of the car an aerodynamic shape, as in a wing turned upside down.

Essentially, the faster the airflow under the car compared to that over the car, the more down-force you will get and therefore a great deal of effort is placed into accelerating the flow under the car as it produces less drag than generating down force from wings etc. By creating low pressure "suction" zones behind the beam wing and the rear wheels you encourage more air to flow under the car and thus improve the down-force of the car.

[Just_a_fan]

http://www.mulsannescorner.com/diffuser.htm
http://www.atlasf1.com/2000/feb16/gray.html
might help.

The rear wings and the general wake of the car are what 'sucks' the air through the underfloor zone. Indeed, the principle reason for lifting the rear wing was to try to reduce the coupling of the rear wing and the diffuser. I'm surprised the new rules didn't also ban the beam wing too which would have had a large impact on the downforce generated by the floor.

Getting the beam wing to work well is why the teams are trying to hard to get good airflow to the rear of the cars. Look at the pictures of Massa's recent fire and you can see how powerful the upwards flow caused by the beam wing is. This is what helps pull air through the underfloor. The diffuser acts to slow the air down as it exits the underfloor - if it didn't, the air would have to slow down very suddenly which would greatly increase drag as well as reduce the mass flow through the underfloor.

[furnik28]

if you back on page 13 of the photo of the cameraman look on his right you can see the exsaust quite clear

[horse]

The diffuser acts to slow the air down as it exits the underfloor - if it didn't, the air would have to slow down very suddenly

I believe that is a bit of a myth, you see. The air does not have to slow down. As the two air streams exit the top and bottom of the diffuser, a vortex sheet is generated if the two streams have non-matching velocity. The greater strength this has, the greater the resulting drag/interference, I would surmise.

[Just_a_fan]

The diffuser acts to slow the air down as it exits the underfloor - if it didn't, the air would have to slow down very suddenly

I believe that is a bit of a myth, you see. The air does not have to slow down. As the two air streams exit the top and bottom of the diffuser, a vortex sheet is generated if the two streams have non-matching velocity. The greater strength this has, the greater the resulting drag/interference, I would surmise.

[horse]

All right, on reflection, I guess that Just_a_fan and I are talking about the same things, just said differently.

Hey, I'm an academic, "pedantic" is my middle name.

[dren]

The diffuser acts to slow the air down as it exits the underfloor - if it didn't, the air would have to slow down very suddenly

I believe that is a bit of a myth, you see. The air does not have to slow down. As the two air streams exit the top and bottom of the diffuser, a vortex sheet is generated if the two streams have non-matching velocity. The greater strength this has, the greater the resulting drag/interference, I would surmise.

The expansion creates faster moving air under the car, thus lower pressure in that area. The beam wing has a lower pressure on its underside, which helps to suck air out of the diffuser, speeding up the airflow even more under the car and creating even more downforce.

[Sebp]

What's going on here?
I'm guessing this is KERS-cooling related as they had some issues in Jerez.
Are those KERS batteries?

[timbo]

I'm guessing this is KERS-cooling related as they had some issues in Jerez.
Are those KERS batteries?

It's fuel tank inlet.

[BreezyRacer]

Very interesting but I don't have a clue what they are. I just cannot imagine mounting batteries that high in the chassis. Maybe left uncovered for cooling though ..

[Sebp]

I'm guessing this is KERS-cooling related as they had some issues in Jerez.
Are those KERS batteries?

It's fuel tank inlet.

I know that is the place where used to insert the fuel nozzle but why would they drive around without the lid?