xpensive wrote:vonk wrote:
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My MS in aeronautical engineering (RPI) has been helpful in this.
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Not really sure what that is, but if it's referring to some kind of university degree, you are definetly hiding it well.
Your posts should also benefit greatly from less of what you yourself call; "techno-babble", never ever seen that much word-dropping on F1T before; bounary-layers, separation, stagnation, vortexes, slip-conditions and velocity gradients...
You know, I was mostly reading this entire thread because I found the sheer lack of knowledge certain people have about anything aerodynamic amusing. It's nothing to be ashamed of; It's a very, very complicated subject. This
is rocket science.
Then Vonk just
had to go and toss around the RPI christened MS in Aeronautics. As someone who went to RPI for the same degree, this is beyond embarrassing. I promise it's a good school. Scout's honor.
Ad hominem attacks aside, I'd like to add one or two points which may or may not help some thought processes. Findings in this field change on the monthly basis, so take what I say with a grain of salt.
1) There is no physical law which states that the air needs to be moving at free stream velocity upon exit of the diffuser. I know for me, it was much easier to understand downforce when I thought the air HAD to move faster under an airfoil simply because it was a longer, curved surface. In reality it's an extremely complex conservation of angular momentum flow problem at work (the Kutta–Joukowski theorem).
2) If you want to think of a diffuser as a pump, there is absolutely work being done. There's a nice big V8 powerplant driving the air through the diffuser.
3) All aerodynamic components on a formula 1 car are functioning in an open system. wings included. Simply because there are gaps connecting free stream to the manipulated flow, does not mean that the manipulated flow is by default at free stream pressure. It may be true for incompressible flows but not for air at sea level. This quote puts it very simply (and curiously unreplied to by vonk):
horse wrote:
In even more simple terms your argument that an open system can not generate a pressure difference is absurd. If this were the case planes would never leave the ground.
One last point:
Arguing a point for arguing-a-point's sake is sometimes counterproductive, and almost always annoying.