marekk wrote:ringo wrote:The flow does not go under the floor!!
Still no change.
Nice try ringo, but to be fair you should take into account:
1. Exhaust flow is already bended at the start (15-30 degree, hard to tell from the pictures).
2. Exhaust density and momentum is 2-3 times lower.
3. Exhaust flow is very turbulent.
4. Exhaust is slowed down by hitting airfoil-shaped (heat shield) part of the floor.
Or do you think it doesn't matter ?
I included the density in the calculation. And it still doesn't tell the whole story becuase their are density changes, then the boundary layer is nowhere near the flow as it is on the floor, a few cm back and very short in height.
All these things you are now accepting, which you didn't accept before are all considered in the CFD. It's not like i wrote the code for the program.
What you also fail to realize is that the barge board deflects most of the cross flow air any way so the paper cannot directly apply. The incidence angle wont be 15 degrees.
I just used the paper to show you that what you were saying is not true, even with that data.
Best proof ?
There is no downforce gain from blowing wide to the sides, just drag reduction, if any. And lap time is definitely downforce limited. No doubt about it.
This car is quick, even with added weight of structures/pipes/fuel, loss engine power and not optimal packaging.
Have you been reading the thread?
There is a considerable down-force gain at the front of the floor and generally under the floor, because the effective size has been increased by blowing to the sides. The pipes are making a skirt around the floor, while entraining air from the splitter area. That theory is holding very well from it's inception.
And can you explain how
...[this flow] is being screened of by the fast moving inflow comming in from the splitter.
I tought it will be sucked into low pressure area created by fast moving inflow, like all other fluids do.
Flow lines cannot be crossed, they can only be moved or destroyed by an impinging flow. As it is the exhuast flow is not strong enough to divert the flow that is already established under the car. It's better off influencing the weaker wake behind the front wheel.
As to why there is no inflow to the floor from the sides, The sidepods have low pressure flow to the side of them, then there is the wheel wake. Secondly even on plane wings the low pressure flow goes outwardly. The inflow is usually just at the edges, it doesn't engulf the whole undercarriage. If it did the car would lose all down-force.
The floor also has a T shape, so there are many things why prediction and rules of thumb don't help much.
Source?
