For Questions That Don't Merit Their Own Thread

[StrandedonEarth]

3 hours ago, K^2 said:

As much as V2 has demonstrated the potential, the fundamental design is not scalable to an orbital rocket. A lot of the components had to be completely reimagined, and that takes time.

Fun fact: when developing the A4 (which became the V2), rather than develop a new, larger injector for the larger engine, von Braun and crew used eighteen proven injectors. How many injectors can one use on a single chamber before it gets sillly? So yeah, scaling that up would not work 

[DDE]

49 minutes ago, SOXBLOX said:

People's Liberation Army Navy Marine Corps? 

Who are a smaller marine force than the Army's amphibious brigades? Don't get me started.

41 minutes ago, StrandedonEarth said:

Fun fact: when developing the A4 (which became the V2), rather than develop a new, larger injector for the larger engine, von Braun and crew used eighteen proven injectors. How many injectors can one use on a single chamber before it gets sillly? So yeah, scaling that up would not work 

And it's not like those showerhead injectors were particularly good.

[kerbiloid]

48 minutes ago, StrandedonEarth said:

when developing the A4 (which became the V2), rather than develop a new, larger injector for the larger engine, von Braun and crew used eighteen proven injectors.

You just explained me the origin of our shower head and its strange set of holes.

I had a feeling, it looks strangely familiar...

P.S.
Oops, kinda ninja'd,

Edited September 22, 2021 by kerbiloid

[kerbiloid]

1 hour ago, SOXBLOX said:

People's Liberation Army Navy Marine Corps Air Assault Battalion

 

[DDE]

7 minutes ago, kerbiloid said:

 

But can they beat the French Mechanized Parahussars?

[kerbiloid]

Compared to that, the American Armoured Cavalry sounds just knightish.

[JoeSchmuckatelli]

Neigh! 

[wumpus]

21 hours ago, JoeSchmuckatelli said:

I would never bet against life finding a way to survive. 

If life could survive in a vacuum in the Van Allen belts, it will be thriving on Mars now.  We've found Mars rocks on Earth, we should expect Earth rocks to have made it to Mars.

Maybe there is some life on Mars that we are missing.  Certainly the lack of life makes the jump from non-life to life on Earth even more improbable.

[DDE]

LOL, looks like our discussion may have had far-reaching consequences. This dropped 6 hours ago.

 

[magnemoe]

6 hours ago, K^2 said:

Even during takeoff and landing there is enough authority to counteract rolling torques due to bad CoM. What you don't want is to have a lot of that torque already there in case of an engine failure, where you need extra authority to keep the single operating engine from flipping the plane over. So it's still very important to make sure your CoM is inside the envelope, but yeah, if people move side-to-side during cruise, it won't matter at all.

Back-and-forward is a major problem even in cruise, not because you wouldn't have authority, but because you loose dynamic stability. In particular, CoM shifting too far back can easily be catastrophic. It creates a pitch-up tendency, which only grows if not immediately corrected. A plane with CoM too far aft once stalled cannot be recovered. I'm not aware of any passenger planes going down because of that, but cargo planes with unsecured cargo that shifted in flight absolutely have.

I was on an regional flight who was less than half full, most has selected seats in the front but we was moved backward because of balance. 
And all who flown planes in KSP know about the CoM far aft problem then you drained most of your fuel  

Was an newspaper story of an group of golfers going on an weekend trip to an golfing destination, airliners had accounted for the golf bags all had as this was an weekend location so most passengers had only light hand luggage. 
The golf bags was to be sent on an later plane who could not take off  because of technical issues. 

[magnemoe]

1 hour ago, kerbiloid said:

Compared to that, the American Armoured Cavalry sounds just knightish.

Armored cavalry makes sense as in blitzkrieg, You penetrate the enemy lines and create an total chaos there. Much in how cavalry was used historically. 

Now the US marines has carrier but only for helicopters and vtol crafts so they have an air force, in fact I think most of them also carry landing crafts in an boat deck 
They also has tanks and artillery, and get sent to landlocked countries like Afghanistan.

[DDE]

19 minutes ago, magnemoe said:

Armored cavalry makes sense as in blitzkrieg, You penetrate the enemy lines and create an total chaos there. Much in how cavalry was used historically. 

It's not mutually exclusive

and partly compatible.

 

[kerbiloid]

26 minutes ago, magnemoe said:

Armored cavalry makes sense as in blitzkrieg, You penetrate the enemy lines and create an total chaos there.

I believe, an horde of horse riders would indeed shock the enemy nowadays!

27 minutes ago, magnemoe said:

Much in how cavalry was used historically. 

Not sure if so, as the main purpose of the light cavalry was making circles and shooting arrows, while heavier one were using lance/pique recurring ramming.

Later all of them became a riding infantry.

30 minutes ago, magnemoe said:

Now the US marines has carrier but only for helicopters and vtol crafts so they have an air force, in fact I think most of them also carry landing crafts in an boat deck 
They also has tanks and artillery, and get sent to landlocked countries like Afghanistan.

They just lost their horses replacing them with soulless motors.

While the new tank battalions were being made from scratch and were not a cavalry.

7 minutes ago, DDE said:

It's not mutually exclusive

And as we know, originally there were two kinds of tanks: an infantry tank, fat, slow, and lazy; and a cavalry tank, fast but weak.

[mikegarrison]

7 hours ago, K^2 said:

Even during takeoff and landing there is enough authority to counteract rolling torques due to bad CoM. What you don't want is to have a lot of that torque already there in case of an engine failure, where you need extra authority to keep the single operating engine from flipping the plane over. So it's still very important to make sure your CoM is inside the envelope, but yeah, if people move side-to-side during cruise, it won't matter at all.

Back-and-forward is a major problem even in cruise, not because you wouldn't have authority, but because you loose dynamic stability. In particular, CoM shifting too far back can easily be catastrophic. It creates a pitch-up tendency, which only grows if not immediately corrected. A plane with CoM too far aft once stalled cannot be recovered. I'm not aware of any passenger planes going down because of that, but cargo planes with unsecured cargo that shifted in flight absolutely have.

Given the state of understanding of hypersonic flight at the time? Very doubtful.

I mean, how early in the 50s? Sputnik 3 in '58 was already over a ton. That's more than enough for a manned flight to orbit. You just don't have the tonnage for an engine that brings you back.  If we are talking about early 50s, there was tech for suborbital flights, but engines you needed for orbital flight were still in development. As much as V2 has demonstrated the potential, the fundamental design is not scalable to an orbital rocket. A lot of the components had to be completely reimagined, and that takes time. Getting from V2 in '45 to Sputnik in '57 was already very fast.

Too many things lined up in the 60s tech-wise. Better understanding of hypersonic flows, better understanding of rocket engines, better materials, computers. Can't forget computers. Even if US didn't drag their feet early on and beaten USSR to first man in orbit, and even if Apollo 1 didn't go up in flames and luck was entirely on US side, it'd still be just a few years sooner.

side to side in fuselage no prob. not enough lever arm.

fore aft can be big prob. has crashed airplanes.

ex. 747 afghanistan when cargo shifted on takeoff.

3 hours ago, StrandedonEarth said:

Fun fact: when developing the A4 (which became the V2), rather than develop a new, larger injector for the larger engine, von Braun and crew used eighteen proven injectors. How many injectors can one use on a single chamber before it gets sillly? So yeah, scaling that up would not work 

lots of airplane engines with more injectors than that for one combustor.

Edited September 22, 2021 by mikegarrison

[mikegarrison]

 

Edited September 22, 2021 by mikegarrison

[SunlitZelkova]

8 hours ago, SOXBLOX said:

LOL.

How about the People's Liberation Army Navy Air Force? Or the People's Liberation Army Navy Marine Corps? 

Now, if their Marines start flying aircraft...

They actually already are. The PLANMC has a Marine Aviation Brigade with Z-8C helicopters (copy/license built SA 321 Super Frelon).

[JoeSchmuckatelli]

5 hours ago, mikegarrison said:

 

I have always loved cut-away illustrations... especially from back in the day, when they were actually illustrations!

Also - first time I've seen that particular word used on anything other than a cocktail enhancement device: (Twin Annular Premixing Swirler)

[mikegarrison]

Swirlers are used in gas turbine fuel injectors to create a vortex of air that the fuel is sprayed into.

This is not exactly the same, but similar.

 

[monophonic]

15 hours ago, StrandedonEarth said:

Fun fact: when developing the A4 (which became the V2), rather than develop a new, larger injector for the larger engine, von Braun and crew used eighteen proven injectors. How many injectors can one use on a single chamber before it gets sillly? So yeah, scaling that up would not work 

You think many injectors on single chamber is silly? At one point von Braun's team planned to use six chambers on one nozzle for the A10! Presumably each chamber with a silly number of injectors.

[DDE]

20 minutes ago, monophonic said:

You think many injectors on single chamber is silly? At one point von Braun's team planned to use six chambers on one nozzle for the A10! Presumably each chamber with a silly number of injectors.

A lot of the early jet engines used something like thirty smaller chambers.

[kerbiloid]

Aerospike and similar love this.

Spoiler

 

 

[mikegarrison]

16 minutes ago, DDE said:

A lot of the early jet engines used something like thirty smaller chambers.

https://en.wikipedia.org/wiki/Combustor#Can

[wumpus]

21 hours ago, kerbiloid said:

I believe, an horde of horse riders would indeed shock the enemy nowadays!

Not sure if so, as the main purpose of the light cavalry was making circles and shooting arrows, while heavier one were using lance/pique recurring ramming.

Later all of them became a riding infantry.

There was an awfully long time while cavalry often used lance and saber, while infantry used musket.  So they weren't exactly "mounted infantry" then.  Some cavalry units in the American Civil War tried to use saber against other cavalry using rifles, it didn't go well.  There were even some elite French cavalry wearing armor at the time (no idea if they tried it during the  Franco-Prussian war.  Judging by attitudes at the start of the Great War, I'd assume they brought it to the first battle and likely didn't survive  long enough to change tactics).

On the other hand, "riding infantry" is as old as riding horses.  Quite a few battles (especially in the War of the Roses) involved English knights dismounted and fighting on foot.

21 hours ago, mikegarrison said:

 

The "bypass" in "high-bypass turbofans" is on the inside?  Didn't expect that.  But I guess it allows for some extremely "high bypass" bits.

[JoeSchmuckatelli]

3 hours ago, wumpus said:

Some cavalry units in the American Civil War tried to use saber against other cavalry using rifles

You should look at the initial American conflicts with the Comanche.  Muzzle loading infantry or dragoons (mounted infantry that fight on foot) did not make it.  The Comanche, using light bows and lances were premiere light cavalry and dominated those first engagements. 

Only the development of the repeating rifle and the tremendous mismatch of population pressures spelled the end of their dominance of the southern Plains. 

(Kentucky rifles worked great in the woods and hills of the East - but in the open Plains, old school Cav still dominated 

[mikegarrison]

3 hours ago, wumpus said:

The "bypass" in "high-bypass turbofans" is on the inside?  Didn't expect that.  But I guess it allows for some extremely "high bypass" bits.

No. Bypass air is on the outside. They just aren't showing you what is in the centerline of the engine because it was not the point for the illustration.