beelsebob wrote:
Hah! That intuition is what gave us cars with wings on top before ground effect cars. It doesn't sound right that more air under the car should work as a good solution to sticking the car to the ground, it sounds like it should make for a high pressure zone under there, but the intuition is wrong. As long as you treat the air flow right, you make it work like a jet engine, speeding up the airflow under the car enormously, and creating a huge low pressure zone.
Thank you!
flyboy2160 wrote:
how do you know this is true? CFD? tunnel data? intuition?
i suspect that if you tried to divert most of the air under the monocoque nose under the floor, you'd have little downforce and the car would lift.
many times on this forum posters are claiming that 'more' air is desirable under the floor. this isn't true. downforce reduction is what the fia has achieved by raising the floors above the ground over the years with schemes such as reference planes and no-wear planks which allow more air under the car. the teams would like to run the floors and the splitter lower than what the fia wants - witness everyone crying about the red bull splitters running lower than everyone else and ferrari's 'flexible floor' a few years back.
the chapparal and brabham sucker cars tried to exclude as much air as possible from below the car and reduce the pressure there by 'evacuation.' since sliding skirts were banned long ago, teams are trying to 'aerodynamically seal' the sides of the floor and the diffuser to prevent air from getting under the floor.
if you think about it a little, you'll realize that more air under the car isn't what you want.
edit: as a thought experiment look at the chapparal and imagine that instead of the sucker fans pulling the air out from that sealed area under the car, the diffuser is doing the sucking. now if you raise the skirts and the nose dam to let more air in, the sucking down on the underside of the car isn't as strong.
First of all teams are not only sealing the diffuser to stop (minimize) tire squirt but they are trying to stop airflow from going out as well! Ride height is one thing and the volume of air under the floor at a given height is another...yes you want the car to run lower because it will get the low pressure point closer to the road surface...forcing more air under the floor will force more air out of the diffuser, speeding up the airflow thus producing more downforce...after all it is air itself that produces the downforce..thats why when cars bottom out lose downforce... regarding your so called 'thought experiment' the chapparal and brabham cars did not 'exclude air' from under the floor..they were accelerating air from under the floor reducing its pressure....it is not possible to 'exclude air' because it is not a closed chamber...air will get in to replace the air you 'excluded'....
last but not least...yes! i know all these from CFD tests..but pls dont make me do another one...it is too time consuming and impossible to do at this stage because of exams...
so..yeah..i suggest that you need to think about it
Edit:
P.S. mods im sorry for discussing all these in the F138 thread..