IT is not like an aeroplane wing where stalling and drag is strongly affected by angle of attack. This is why people correlate stalling and drag together. Don't think about what people say, think carefully about the physics behind it.kalinka wrote:ScarbsF1 wrote this on his blog :
"As no flow passes to the rear wing vent the rear wing produces its normal amount of downforce to aid cornering. However on long straights the driver can move his leg from the brake pedal and press it against the opening in the duct, this sends the airflow from the snorkel through the duct to the rear wing vent. This airflow disrupts and stalls the wing adding some 3-4mph (6kmh) to the cars top speed. As he moves his leg from the duct to the brake pedal the airflow returns to the previous condition and the rear wing gains downforce once more."
I a bit confused about this. I was following this forum for a long time, and I thinbk most of the people here agreed, that blowing the wing reduces possibility of stalling, and increases downforce. I found some studies myself about this on internet. So for me, ScarbsF1 is wrong. The effect is opposite. When you go on straight, you have to CLOSE the snorkel, therefore disabling the blowing of the wing, to INDUCE stall. Am I wrong ?
OK, it does not change but one of the benefits of this system should be that if you blow the wing you can go with higher angle of attack than your opponents without adding too much drag and without stall. This applies though only in situations where you blow the wing in corners, and doesn't blow on straights. Still confused. ScarbsF1 doesn't write stupid things on his blog as I know, but even so, everything that I learned so far indicates that he is wrong. I am following this "blown wing saga" from the beginning, and for me it was obvious from the beginning that the blown wing is the normal operation and stall occurs when there is no blowing.n smikle wrote: IT is not like an aeroplane wing where stalling and drag is strongly affected by angle of attack. This is why people correlate stalling and drag together. Don't think about what people say, think carefully about the physics behind it.
Remember in F1 the angle of attack does not change during the race.
tok-tokkie wrote:The diagram of the fluidic device is for the bi-stable design.
If the geometry is slightly altered then the Coanda effect can be biased to one side. Only one control port is then required. While a signal is present at the control port the output switches to the other output port. That is what I expect McLaren have done.
When the signal is not present then the upper wing gets the airflow from above the drivers head. That blown air makes the airflow adhere to the upper wing. It causes increased downforce and increased drag. This is regime when cornering.
When the signal is present (when the driver blocks the hole in the duct from the snorkel with his knee {apparently}) the air from the inlet above the drivers head is diverted to exit close to the light at the back of the car. Without air from the slot the airflow separates from the back of the upper wing reducing both the downforce and the drag so the car runs faster.
It is a fail safe design - only when the driver deliberately closes the hole is the downforce removed.
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The Wiki article has been heavily revised since i first saw it. It now refers to a flip-flop which is what I said in my initial posting about it here on 3 March.
kalinka wrote:OK, it does not change but one of the benefits of this system should be that if you blow the wing you can go with higher angle of attack than your opponents without adding too much drag and without stall. This applies though only in situations where you blow the wing in corners, and doesn't blow on straights. Still confused. ScarbsF1 doesn't write stupid things on his blog as I know, but even so, everything that I learned so far indicates that he is wrong. I am following this "blown wing saga" from the beginning, and for me it was obvious from the beginning that the blown wing is the normal operation and stall occurs when there is no blowing.n smikle wrote: IT is not like an aeroplane wing where stalling and drag is strongly affected by angle of attack. This is why people correlate stalling and drag together. Don't think about what people say, think carefully about the physics behind it.
Remember in F1 the angle of attack does not change during the race.
Wouldn't it be more realistic that the driver simply must break the airflow from the snorkel by pressing his leg against a flexible tube ?(on straights ). If the system works an opposite way ( like ScarbsF1's ), the driver has to seal a little hole with his leg on the tube. It's much harder than pressing a tube, because you have to find the exact place with your leg/knee and seal it completely.
Again, I'm not telling you that my theory is right, just it sounds more realistic to me. I'm not going into battle for this. Just think about it.
another thing is..other teams usually blow the bottom wing. This year is Mclaren also blowing the bottom wing?tok-tokkie wrote:The diagram of the fluidic device is for the bi-stable design.
If the geometry is slightly altered then the Coanda effect can be biased to one side. Only one control port is then required. While a signal is present at the control port the output switches to the other output port. That is what I expect McLaren have done.
When the signal is not present then the upper wing gets the airflow from above the drivers head. That blown air makes the airflow adhere to the upper wing. It causes increased downforce and increased drag. This is regime when cornering.
When the signal is present (when the driver blocks the hole in the duct from the snorkel with his knee {apparently}) the air from the inlet above the drivers head is diverted to exit close to the light at the back of the car. Without air from the slot the airflow separates from the back of the upper wing reducing both the downforce and the drag so the car runs faster.
It is a fail safe design - only when the driver deliberately closes the hole is the downforce removed.
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The Wiki article has been heavily revised since i first saw it. It now refers to a flip-flop which is what I said in my initial posting about it here on 3 March.
