Intake plenum and 911 throttle body

[KRAM36]

Originally Posted by Jamesp

As an engineer, it's entertaining to watch the other engineers try to explain technical principles to non technical folks. Without a technical education folks will believe what they want to believe (suction is a great example). At some point you just have to say, "I can explain it to you, but I can't understand it for you."

I don't see where you explained anything? Try me, I'm not afraid to learn.

From the simulation. "The volume flow rate results show that the T and T with wedge have almost identical flow rates." Yet Pedro's video shows the opposite.

Originally Posted by jsceash

I like that

jsceash can you explain this? Is the simulation wrong? Did Pedro sneak a magic trick in on you? I can't imagine Pedro could pull one over on a smart guy like you.

[jsceash]

I'll try a different way.

Have you ever gone fishing in a trout stream and watched a bend in the stream with a back eddy. The water spins backward and slows as it gets away from the current the speed up as it comes back around. A portion of the stream flows back continuously. It really obvious if there is a can or foam cup floating in it. That is what happens in the long radius flat back Porsche Plenum.

Now imagine the same stream and same bend if someone built a concrete barrier in the outside radius. The water would glide past at a faster speed or equal to the rest of the stream current. The IPD and or Pedro's Plenum.

Pedro's video is a bit of truth a bit of exaggeration. It exploits the defect in the stock plenum. The dead space becomes larger as the velocity of air is increased it is a principle in air flow called a "Boundary air layer". "Turbulent boundary air" is proportional to the air velocity so the turbulent area increases as the air velocity increase. Pedro uses a vacuum to blow air in the plenum which creates a higher velocity than the NA motor can produce but it is fast enough to exaggerate the flow problem. I've been trying to explain all day that turbulent air is like a plug reducing flow. The second type of boundary air layer is "Laminar Boundary air" its the drag created from the air friction with surface of the pipe. This is proportional to the square root of the velocity so it increases slowly as the velocity increases so it has little effect in the application. The big thing you see this affect is golf balls put dimples in the surface you can defeat the effect. Pedro uses a Teflon insert which has a low friction coefficient. IPD used of epoxy coat them but now the shot peen the inside so it like the dimples on a golf ball either way they negate the effect at the air flow speeds for the application

[Jamesp]

[QUOTE=KRAM36;451898]I don't see where you explained anything? Try me, I'm not afraid to learn.
QUOTE]

Wanting to learn is good! As B2000 pointed out we are discussing fluid flow which brings us to Navier-Stokes. Many years ago I had the pleasure of learning fluid dynamics and aerodynamics which just wouldn't be the same without the good old Navier-Stokes equations. The material isn't completely transparent, so I've included this wiki link to get you started. You'll want to brush up on tensors to get the full impact. Here's the link:

Navier

Now don't say I haven't tried to explain anything to you.

[blue2000s]

[QUOTE=Jamesp;451945]

Originally Posted by KRAM36

I don't see where you explained anything? Try me, I'm not afraid to learn.
QUOTE]

Wanting to learn is good! As B2000 pointed out we are discussing fluid flow which brings us to Navier-Stokes. Many years ago I had the pleasure of learning fluid dynamics and aerodynamics which just wouldn't be the same without the good old Navier-Stokes equations. The material isn't completely transparent, so I've included this wiki link to get you started. You'll want to brush up on tensors to get the full impact. Here's the link:

Navier

Now don't say I haven't tried to explain anything to you.

The cool thing about the Navier Stokes equation is that it's really just a fluid flow adaptation of F=mA. It all comes back to Newton. Until you go down so the sub atomic level, anyway.

[Jamesp]

[QUOTE=blue2000s;451952]

Originally Posted by Jamesp

The cool thing about the Navier Stokes equation is that it's really just a fluid flow adaptation of F=mA. It all comes back to Newton. Until you go down so the sub atomic level, anyway.

Spoken like a true engineer! I moved away from hard core technical (thermal analysis on the Space Shuttle / systems design) years ago and became a manager (after my spine-ectomy), got fed up with personnel issues, budgets, long hours, and politics and so became a "systems" engineer which means I'm a jack of all trades, and master of none. Mainly work various spacecraft systems issues and project management now. Thanks for the insight on the bend radius.