2 stroke thread (with occasional F1 relevance!)

[nzjrs]

manolis, please stop with the rocket fallacy stuff. The question is whether the pilot, by sticking his/her legs into the air stream from the propellers will be able to generate enough torque to control the flyer, and whether the pilot will be able to generate this torque with his/her muscles over time.

Indeed.

(and whether the dynamics of any reaction from these deflections into the airstream are relevant to the flight envelope of the PF - or is this just pissing off the side to turn a cruise ship - Pull up! Pull up! drip drip drip)

Additionally

if – for some reason – the one propeller provides, say, 10% more lift than the other, the pilot displaces his body for some 25mm / 1” towards the “stronger” propeller (the propeller axes are at about 500mm distance from each other) to cancel out the thrust imbalance

Similarly for the reaction torque (in this case the pilot arranges his limbs slightly unsymmetrical to cancel out any imbalance of reaction torque from the propellers).

Hmm, a rare explicit measured prediction. This seems like the kind of hypothesis which could be tested using any of the numerous quantitative (i.e. literally almost anything except pictures of babies or animals) analysis techniques that have been suggested in this thread.

[manolis]

Hello Coaster

You write:

• Btw i like the wide rotating paddle wing concept, a bit draggy at the edges though.

The animation you reffer to, shows only the central part of the blades (i.e. they are neither wide nor short) and the hub that causes the variable pitch.

Similarly the following animation shows only the central part of the blades:



More for the PatPitch at http://pattakon.com/pattakonPitch.htm



By the way, this slide:



is taken from the following youtube video of Tom Stanton:




Tom Stanton could improve his demonstration / leason by making one significant further step:


(ignore the background)

i.e. he could: reverse the thrust, put the "pendulum" to fly UPSIDE DOWN (with the thruster being substantailly bellow the center of mass) and video it . . .

Thanks
Manolis Pattakos

[coaster]

Maybe standing above a shrouded contra rotating propellor? It would need vectoring, a gimbal mount. Study Von Brauns V2 thust vectoring, without it working V2's only flew a few kilometers before nosing downwards.
Thats gonna make a very sore head.

[Rodak]

Study Von Brauns V2 thust vectoring, without it working V2's only flew a few kilometers before nosing downwards.

And why did they crash? Obviously because of the rocket pendulum fallacy!

[nzjrs]

Study Von Brauns V2 thust vectoring, without it working V2's only flew a few kilometers before nosing downwards.

And why did they crash? Obviously because of the rocket pendulum fallacy!

In addition to Wernher von Braun not understanding the pendulum rocket fallacy he made a second design mistake.

You see, the V2 were controlled by a very early inertial navigation system, but it was not perfect. A fatal flaw! The PF stabilisation of manolis will have no such problems because it will use the smartest control system ever designed - the human mind (featured also in babies learning to walk and unicyclists)

Jokes aside, the V2 INS and the history of the things they tried is super interesting. http://www.astronautix.com/v/v-2.html for example.

[J.A.W.]

Study Von Brauns V2 thust vectoring, without it working V2's only flew a few kilometers before nosing downwards.

And why did they crash? Obviously because of the rocket pendulum fallacy!

In addition to Wernher von Braun not understanding the pendulum rocket fallacy he made a second design mistake.

You see, the V2 were controlled by a very early inertial navigation system, but it was not perfect. A fatal flaw! The PF stabilisation of manolis will have no such problems because it will use the smartest control system ever designed - the human mind (featured also in babies learning to walk and unicyclists)

Jokes aside, the V2 INS and the history of the things they tried is super interesting. http://www.astronautix.com/v/v-2.html for example.

At the risk of straying even further from the topic, (but further to your post above),
one literally 'bird-brained' solution tried (& it worked, experimentally) way back in WWII
to overcome primitive electro-mechanical guidance control, was the pigeon-guided missile,
with a 'Skinner-box' trained bird watching for the target, & pecking in control commands!
(& the Japanese, of course, also made grim use of human-guided missiles in combat).

As for "the human mind", one of the post-war uses for the leftover stockpile of V2 fuel,
hydrazine, was in MAOI anti-depressants, but it seems the supply might be used up now..

https://ajp.com.au/news/supply-shutdown

[Rodak]

Yeah. I was the son of a Boeing engineer involved in the moon program (second stage hydrogen motors) and, for a couple of years, lived in Huntsville, Alabama, home of the Marshall Space Flight Center where the Saturn 5 was developed. Von Braun was a huge influence in the early days of American rocketry after the war (the Redstone was a V2 redo) but let's not get into his political side.... We used to hear and see tests of the Saturn 5 F1 engine that would shake the ground for miles around and shoot huge clouds of exhaust and steam into the air; I also saw two moon launches at Cape Canaveral. Truly impressive; and, as an added benefit, they proved the rocket pendulum fallacy!

[nzjrs]

Yeah. I was the son of a Boeing engineer involved in the moon program (second stage hydrogen motors) and, for a couple of years, lived in Huntsville, Alabama, home of the Marshall Space Flight Center where the Saturn 5 was developed. Von Braun was a huge influence in the early days of American rocketry after the war (the Redstone was a V2 redo) but let's not get into his political side.... We used to hear and see tests of the Saturn 5 F1 engine that would shake the ground for miles around and shoot huge clouds of exhaust and steam into the air; I also saw two moon launches at Cape Canaveral. Truly impressive; and, as an added benefit, they proved the rocket pendulum fallacy!

Oh wow, super jealous! Friends and I made plans to visit USA just to watch the final space shuttle launch, but we didn't go through with it - I regret that decision still.

[coaster]

Rocketry could deserve a thread all of its own, very interesting, but can get buried deep in math, which isnt my strong suit.
I pray nobody gets hurt with all these unshrouded propellor 'ideas'.

[manolis]

Hello all.



Opposed piston Pulling Rod Engine with Tilting valves

86mm bore, 30+30=60mm combined stroke.

More at https://www.pattakon.com/pattakonTilting.htm

Thanks
Manolis Pattakos

[flynfrog]

looks like you need to add some ballast to that stand.

[Rodak]

looks like you need to add some ballast to that stand.

I was thinking some bolts might be nice.

[Big Tea]

looks like you need to add some ballast to that stand.

Contra rotating flywheel?

[Brake Horse Power]

Has this been posted yet?

[gruntguru]

Amazing! Who does their graphics . . . . and music?