Simple Tunnel ram Question

[ptuomov]

If I post this photo, it will rate about median on the on/off topic dimension for this thread:

0C80BAEC-2964-49DE-8C74-0701715D2802.jpeg

[MadBill]

...I still don't see why people are haveing such a hard time understanding gravity's effect during the time a mass is accelerating.

Yes, how can so many of us be so wrong, all in the same way?

"Look Martha, everyone in the band is out of step except our boy!":-k

[Kevin Johnson]

If I post this photo, it will rate about median on the on/off topic dimension for this thread:

0C80BAEC-2964-49DE-8C74-0701715D2802.jpeg

That's obviously a shot of Niven's Ringworld.

[ptuomov]

Nantucket, but the Ringworld would be pretty close in terms of construction cost and the ease of entry/exit.

[makin chips]

With that tunnel ram, I predict it would work better inverted than in the normal up right operating position. So just the inverse of what jcc thought would be the most efficient. When I win the power ball I'll be able to test the theory.

And for the acceleration gravity guy. When your standing still what is your measurable acceleration, to the ground? That is the rate of change of your velocity with respect to time?

I bet if you were to put 3x2bbl updraft carbs on it, that thing would likely implode from sucking so hard

[cardo0]

Is the fact that a typical Tunnel ram uses gravity more effectively then any other NA manifold give it an inherent notable advantage?

I guess vertical IR stacks might share also share the same advantage regarding gravity.

This conversation has given me some better insight as to the TR characteristics. If the plenum area is large enough it can act as a single pressure boundary where the Helmholtz reflected wave can reflect off of. Meaning it provides the tuning length of the runner.

Most TR or any other tuned intake runner length is using the 1/4 wavelength for resonance amplification but why we don't see taller rams using the 1/2 wavelength I don't know - maybe that would halve the rpm where peak power occurs then. I know a full wavelength has to much restriction due to the losses over the runners long surfaces besides there is no place to install runner tubes that long. It would be nice to have intake runners cut to length for dedicated engines. Makes me wonder why the TPI died so fast and most want to forget about it. I can admit I know nothing 'bout the LS intake science so I'll let someone else take us there.

[BenE64]

dual plane.jpg

So to help me understand this better.
if we take a single section of dual plane for an example, these two setups would operate identically due to the fact that all the conditions are identical and gravity has no effect what so ever on the air and fuel travelling through this piping? While the engine is running.

I am really struggling to understand how it doesnt have an effect. Even more so if it was a single cyl and the air speed changes were more pronounced?
I really have been thinking about things all wrong.
No more posts from me after this.

[SchmidtMotorWorks]

From tuners pdf:

I am wondering how this adds to the gravity argument.

Gravity is not mentioned as a variable in the computation of airflow through a nozzle.

air.JPG

Nor is it mentioned in computation of fuel flow other than head, however that is a presume difference than occurs independent of gravity.

fuel.JPG

[digger]

gravity does not affect air in an air system because the buoyancy force and gravity force are equal and opposite so cancel out (draw a free body diagram of a small piece of air). Strickly speaking the change in potential energy is gravity driven but its usually negligable as the height does not change much over the length of manifold so the number ends up very small (in any case the change in height is what matters not how vertical it is).

fuel behavour is totally different though

[Kevin Johnson]

One of the many problems with the way humans reason and the structure of language is that abstractions become reified. This in combination with negation being an ambiguous prime operator in first order logic creates quite a tangle.

Centripetal force or center-seeking force is reified as a distinct force but can commonly result from tension or a reaction force. Carnival rides typically exploit the latter because hurling visitors to their demise or detaching limbs and then hurling them to their demise tangentially harms revenue (get the double entendre which folds back to both referents?). Centripetal force can be a tension or a reaction force. Humans have difficulty processing that foundational ambiguity can ultimately lead to quite dire circumstance (or vulnerability) because the liberties taken can be quite useful in a local or limited circumstance. Git'r dun.

[Dave Koehler]

Dr Rodney McKay: (Droaning on and on ) Yada, Yada, scientific buzzwords, long sentences yada, yada,

Lt Col John Sheppard : (exasperated, glaring, loudly) RODNEY......will it work or not?

Dr Rodney McKay: Yes,...no.....maybe

[Tuner]

You guys have jumped the shark, you are not understanding the difference between acceleration and steady state and you are confusing gravity with weight. Gravity is an acceleration. (don't argue with me, argue with the physicists who say so, starting with Mr. Einstein) Our concept of weight is the resistance of a mass to Earth's gravity. The effect of gravity is indistinguishable from any other acceleration. When there is more than one acceleration vector, the vectors are added to find the resultant vector of motion. As a result it requires less energy from the engine to accelerate a mass of air down than up. The mass of air in the intake system must be accelerated from zero to port velocity. When the flow is downward the acceleration of gravity acts on the mass independent of and is additive to the force supplied by the engine causing acceleration of the air.

[SchmidtMotorWorks]

OK, tested flow into a 12" long pvc pipe using a 5HP shop vac and a simple inclined manometer (clear tubing with colored water).
The incline of the tubing was about 10 degrees so it is sensitive, it could detect a 3/32" welding rod passed over the opening.

I could move it from horizontal to pointing up or down without turning it off.

No difference detected.

[Tuner]

OK, tested flow into a 12" long pvc pipe using a 5HP shop vac and a simple inclined manometer (clear tubing with colored water).
The incline of the tubing was about 10 degrees so it is sensitive, it could detect a 3/32" welding rod passed over the opening.

I could move it from horizontal to pointing up or down without turning it off.

No difference detected.

Because the tested flow was steady state.

[SchmidtMotorWorks]

You guys have jumped the shark, you are not understanding the difference between acceleration and steady state and you are confusing gravity with weight. Gravity is an acceleration. (don't argue with me, argue with the physicists who say so, starting with Mr. Einstein) Our concept of weight is the resistance of a mass to Earth's gravity. The effect of gravity is indistinguishable from any other acceleration. When there is more than one acceleration vector, the vectors are added to find the resultant vector of motion. As a result it requires less energy from the engine to accelerate a mass of air down than up. The mass of air in the intake system must be accelerated from zero to port velocity. When the flow is downward the acceleration of gravity acts on the mass independent of and is additive to the force supplied by the engine causing acceleration of the air.

For a wheel on a horizontal axle.

tunnel_ram.jpg

If an external force rotates the wheel, accelerating it.
According to your theory, the portion of the wheel going down would requires less energy to accelerate than the portion going up.

If that were true, the wheel would continue to accelerate due to gravity.