Author Topic: Pyro's opinion on 3 flight modelling items? (Read 1490 times)

Dowding · « **Reply #60 on:** May 09, 2001, 10:46:00 AM »

lol Toad. I think that's called a 'mind-blowing revelation'.

RAM: I want the Torque!

HT [In Jack Nicholson mode]: You can't handle the Torque!!

Straffo - while not technically correct, 'spited my cafe around' is much, much funnier. And very literal.

Malhereusement, je parle Francais un peu.

How's that for gramatical inaccuracy (I think)!

Toad · « **Reply #61 on:** May 09, 2001, 11:05:00 AM »

Straffo,

Parce que votre Anglais est donc beaucoup de mieux que mes Français!

[This message has been edited by Toad (edited 05-09-2001).]

sling322 · « **Reply #62 on:** May 09, 2001, 11:57:00 AM »

Quote

Originally posted by R4M:

Sling............learn to read, please. I will quote my words again.....

"I said that "From being a monster (The N1K1-J) it changed to be the kitty it is in AH (the N1K2-j)""

That may be what you said....but its not what Jigster said. He was referring to the N1K1-Ja as a monster and you just conveniently extrapolated that out to make it seem that he was referring to the N1K2-J to suit your own conspiracy theories.

Yoj · « **Reply #63 on:** May 09, 2001, 12:14:00 PM »

Quote

Originally posted by Pepe:
Just an illiterate question here:

Wasn't it right that certain planes (the torque-prone ones, read: BIG engines, HUGE horsepower) could flip over wing if the pilot firewalled the throtle on Take off, even before they move forward?. If so, where this behaviour is modelled?

I repeat, It is not a twisted way of arguing, just curiosity, I've heard or read it somewhere.

Cheers,

Pepe.

I couple cents on the torque question - a plane flipping over due to torque is fairly unlikely unless the pilot is really bad or inexperienced. This is because, while there is a tendency of the plane to roll opposite to the prop, it is proportional to their relative masses. The mass of the plane is much greater than the mass of the prop. The largest force comes from the gyroscopic precession, and it is a yaw force, not a roll force, which is why during takeoff there is some need for aileron input, but much greater need for rudder input.

A good example of the difference is the Sopwith Camel. The Camel's engine was quite powerful for the time, and was a Rotary type - that is, the entire engine turned with the prop. The relative mass of engine plus prop to plane mass was greater than any WW2 fighter, and the Camel did have a tendency to roll opposite to the engine, but it was easily compensated. However, it had a HUGE yaw tendency that could be fatal to a new pilot. It would yaw through 90 degrees in a half loop, and it could turn very quickly in one direction - a fact that the better pilots used to great advantage.

So - suddenly firewalling the engine would likely not flip you over, but could well turn you sideways and cause a loss of control, especially at low speeds.

- Yoj

funked · « **Reply #64 on:** May 09, 2001, 12:29:00 PM »

RAM I've never heard of any such airfield changes, or even an accident where a Typhoon hit a hangar on takeoff. Can you cite a source on this?

Daff · « **Reply #65 on:** May 09, 2001, 01:05:00 PM »

Yoj, what's the secondary effect of yaw?

Daff

------------------
CO, 56th Fighter Group
www.56thfightergroup.org
This is Yardstick, follow me"

Jigster · « **Reply #66 on:** May 09, 2001, 02:17:00 PM »

Ram forgets that the principle aspect of torque is the engine changing speeds, not the plane, granted in high speed flight they are related. It is not limited simply to weight and engine power.

Besides the principle problem with the N1K1-Ja was the rudder was not large enough to compensate on take off, taxing, etc. It was, afterall, a converted float plane design that wasn't really subject to narrow runways.

Most planes with some form of rudder trim, be it a fixed or pilot manipulated one, easily corrected yaw once the plane was airborne. Most of the other aspect of torque are related to the ailerons. The only planes that I pilot had to be aware of it lacked some form of trim, like the, um G10.

[This message has been edited by Jigster (edited 05-09-2001).]

Yoj · « **Reply #67 on:** May 09, 2001, 02:24:00 PM »

Quote

Originally posted by Daff:
Yoj, what's the secondary effect of yaw?

Daff

Sorry Daff - I don't know. I'm not sure exactly what you're asking.

- Yoj

Toad · « **Reply #68 on:** May 09, 2001, 03:40:00 PM »

Yoj, I think he's pointing out that roll is the secondary effect of yaw.

Next, I expect the dicussion to move to the amount of roll. "Easy to counter or death flip? Tune in to Jerry Springer!"

Yoj · « **Reply #69 on:** May 09, 2001, 04:42:00 PM »

Quote

Originally posted by Toad:
Yoj, I think he's pointing out that roll is the secondary effect of yaw.

Next, I expect the dicussion to move to the amount of roll. "Easy to counter or death flip? Tune in to Jerry Springer!"

Ah - it was the emphasis ot "THE secondary" effect that threw me. Roll is certainly A secondary effect. My point was that the plane is not going to throw itself onto its back from twisting in the opposite direction of the prop. If it could, it would be possible when the plane was stationary, just by reving the engine. I could see something like having the yaw slew the plane sideways on takeoff and having impact and inertia flip it. Torque would be responsible, but I don't think that was the gist of Pepe's original question.

- Yoj

Daff · « **Reply #70 on:** May 09, 2001, 05:13:00 PM »

AFAIK, one major factor (while on the ground), is that the yaw will push more weight onto one wheel, again causing further tendency to turn to one side. You're right that planes dont get thrown around by roll..it's usually caused by a sharp turn to the side that will flip the plane the other way as the weight shifts to the outside wheel...but what really puzzles me about the Torque/sideslip/gyroscopic precission in AH is that the moment you lift off, they are virtually non-existant...you actually have to easy off on the rudder. (Something I never had to in a real plane).

Daff

------------------
CO, 56th Fighter Group
www.56thfightergroup.org
This is Yardstick, follow me"

hitech · « **Reply #71 on:** May 09, 2001, 05:14:00 PM »

Sigh, some days I feel like we should have a section on physics 101.

Roll Torque on the plane is very easy to calculate it's simply current HP / prop rpm.

What most people refer to torque, the stuff on take off that makes your plane yaw,has nothing to do with Roll Torque, it has every thing to do with the slip stream/prop wash.

The 2 other forces that produce yaw do to the prop/eng they are gyroscopic (this only produces yaw if you are changing pitch) i.e. when your tail lifts. The final force is PFactor, it only has much effect at high speeds and hi aoa's.

AH Models all 4 prop forces, 3 of which I'm confidant we are with 5% of the real plane.

I'm not happy with our slip stream effects, we have been doing more research into calculating the slip stream, and it will change in some later version.

HiTech

Citabria · « **Reply #72 on:** May 09, 2001, 05:37:00 PM »

awsome HT!

I forsee the return of a need for right rudder when the slipstream is tuned up

juzz · « **Reply #73 on:** May 10, 2001, 01:24:00 AM »

Slipstream, eh... Always wondered why the fighters won't lift the tail until 50mph or more, when most of them should be able to do it at 0mph with a high power setting, just from the propwash over the tail.

straffo · « **Reply #74 on:** May 10, 2001, 02:26:00 AM »

Quote

Originally posted by funked:
RAM I've never heard of any such airfield changes, or even an accident where a Typhoon hit a hangar on takeoff. Can you cite a source on this?

I've read that in the "Grand cirque" (big show) by Clostermann but it's likely an writer "artifice" and as I've not the book near I don't know if it's about the Typhoon or the Tempest.