Offline WTF_Seriously

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Re: FE and ICBMs
« Reply #220 on: June 18, 2021, 01:55:23 PM »
You contend that 159,000 lbs consisted of a, "majority of which is fuel," based on "what exactly?"

Based on the fact that it's going to be quite similar to this:

https://minutemanmissile.com/solidrocketboosters.html as well as this: https://en.wikipedia.org/wiki/LGM-30_Minuteman#:~:text=The%20Minuteman%2DIII%20has%20a,800%20ft%20(240%20m).

I'll highlight the pertinent points for the Minuteman II and III since it appears reading isn't your thang.

1st stage weight 51,251 lbs.  Fuel weight 45,670 lbs.
2nd stage weight 16,057 lbs. Fuel weight 13,680lbs.
3rd stage weight 8,187 lbs. Fuel weight 7,292 lbs.

In case math ain't your deal either, that's total stage weight 75,795.  Total fuel weight 66,642. With the total missile weight of 79,432 that would be 83+% fuel.  I'll give you credit for knowing the definition of majority.


Quote
Any idea on the altitude and rate of travel achieved by the time of engine cut off? It is apparent you disagree with the 4500 km achieved at that time, contending an unpowered ballistic object can continue gaining a significant amount of altitude after impetus is removed.

Didn't take my advice on that high school physics class evidently.  I even pointed out the important things here like initial velocity and acceleration (hint: in this case it's G).  I did forget to mention how to calculate distance traveled.

Extremely curious how high you think a bullet travels when shot straight up.  You do realize a bullet is an 'unpowered ballistic object' once it leaves the barrel, right?

If you'd like to continue your 'Nuh uh!' game that's great.  But please, try not to embarrass yourself in the process.
« Last Edit: June 18, 2021, 02:06:36 PM by WTF_Seriously »
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Offline Action80

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Re: FE and ICBMs
« Reply #221 on: June 18, 2021, 02:26:30 PM »
Thanks WTF_S; 

To confirm, my contention is that the missile launches at a mass of 159,000 lbs, the majority of which is fuel, and all consumed within the initial, single, 5-minute, burn, which accelerates it on a high angle trajectory where y>x.
You contend that 159,000 lbs consisted of a, "majority of which is fuel," based on "what exactly?"

Total burn time = 5 minutes.
Any idea on the altitude and rate of travel achieved by the time of engine cut off? It is apparent you disagree with the 4500 km achieved at that time, contending an unpowered ballistic object can continue gaining a significant amount of altitude after impetus is removed.

Majority of the mass is fuel?  It's an aluminium tube with a 2000lb warhead at one end, and a rocket motor at the other.  You work it out.  What exactly do you think is inside the part between the motor and warhead?  Its a fuel tank or, for a solid fuel motor, containment for the fuel mass.
You have no idea then? The materials necessary would need to be of such strength as to withstand the forces sustained.

In other words, soda can aluminum would not fit the bill and not just any aluminum tube.

Plus, where does the idea of solid fuel come from?

Take a shot at a figure.

Try UDMH weight per gallon, and high tensile strength aluminum and split it all up.
Altitude and velocity at engine shut-down? 

No idea. 
Thanks.
« Last Edit: June 18, 2021, 05:53:16 PM by Action80 »

Offline SteelyBob

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Re: FE and ICBMs
« Reply #222 on: June 18, 2021, 03:28:26 PM »
Great.

So, next we have these two questions.

How many lbs of fuel contributed to the 159,000 lb weight of the missile?

What was the altitude achieved at t+5?

Fuel mass discussed elsewhere. Height at burnout of the order of 250km or thereabouts.

Offline Action80

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Re: FE and ICBMs
« Reply #223 on: June 18, 2021, 03:56:38 PM »
Great.

So, next we have these two questions.

How many lbs of fuel contributed to the 159,000 lb weight of the missile?

What was the altitude achieved at t+5?

Fuel mass discussed elsewhere. Height at burnout of the order of 250km or thereabouts.
Thank you.

So, travelling at just under 3000 km/h at t+5 and having attained an altitude of only 250 km, do you think the missile will continue to rise to an altitude of 4500 km in over or under 53 minutes?
« Last Edit: June 18, 2021, 05:54:46 PM by Action80 »

Re: FE and ICBMs
« Reply #224 on: June 18, 2021, 06:40:11 PM »
Thanks WTF_S; 

To confirm, my contention is that the missile launches at a mass of 159,000 lbs, the majority of which is fuel, and all consumed within the initial, single, 5-minute, burn, which accelerates it on a high angle trajectory where y>x.
You contend that 159,000 lbs consisted of a, "majority of which is fuel," based on "what exactly?"

Total burn time = 5 minutes.
Any idea on the altitude and rate of travel achieved by the time of engine cut off? It is apparent you disagree with the 4500 km achieved at that time, contending an unpowered ballistic object can continue gaining a significant amount of altitude after impetus is removed.

Majority of the mass is fuel?  It's an aluminium tube with a 2000lb warhead at one end, and a rocket motor at the other.  You work it out.  What exactly do you think is inside the part between the motor and warhead?  Its a fuel tank or, for a solid fuel motor, containment for the fuel mass.
You have no idea then? The materials necessary would need to be of such strength as to withstand the forces sustained.

In other words, soda can aluminum would not fit the bill and not just any aluminum tube.   So now you are a stress engineer as well as a mathematician.  Good to know. My guess would be 2024 specification aluminium , or 7075 for high-stress areas.  Maybe some titanium to cope with heat stress.  But, as I said, I'm not a rocket scientist so its just a guess.  As for the soda cans; no idea again.  Beverage Packaging Engineer is another training course I never graduated from

Plus, where does the idea of solid fuel come from?  Many missiles use solid fuel.  Just mentioned it for completeness.  North Korea's SLBM in current development is speculated to have a solid fuel booster. 

Take a shot at a figure.   I think this is your area of expertise. 

Try UDMH weight per gallon, and high tensile strength aluminum and split it all up.
Altitude and velocity at engine shut-down? 

No idea. 
Thanks.   Some people might consider this a weakness.  Whilst it may be a precedent on the Internet if I don't know I'll tell you, rather than make up a number. 


Edit.   Sorry, I've just seen this in your response to Bob; 3000kph at T+5?  What part of left-field did that come from?  That's just a bit faster than Concorde with 100 passengers.  We are talking about a space-rocket FFS.  Do you have your own random number generator on these posts?   

Edit again.   I just worked out what you did; Bob's 250 km in 5 minutes, equates to a constant 3000 kph in your brain!  Brilliant.  You think it got to end of burn from a standing start at a constant 3000 kph!  This is absolutely mind-blowing stuff.  Was that a quadratic equation by the way?  Keep the posts coming, please; this is better than Big Bang Theory.   
« Last Edit: June 18, 2021, 07:02:28 PM by DuncanDoenitz »

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Offline RonJ

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Re: FE and ICBMs
« Reply #225 on: June 18, 2021, 08:16:03 PM »
Maybe A80 needs to ratchet up his math a bit to differential equations.  You have a rocket lifting off with a specific amount of thrust. Everything could be simple with a fixed amount of acceleration over a set time and you could do some quick calculations BUT; A rocket burns fuel at an enormous rate and the bulk of the rocket's mass is from fuel so every pound of fuel burned makes it easier for the rocket to accelerate.  This means that the rate of acceleration is accelerating.  The increase in speed per unit time (acceleration) will be much lower right after liftoff when the rocket is heavy with fuel.  Right before the rocket is empty of fuel and is much lighter, the acceleration rate peaks out.  The final velocity could be quite a bit higher than you might think.  Additionally as the rocket leaves the atmosphere the air drag decreases, and as the rocket gets further from the center of the earth the force of gravity decreases a bit as well.  Everything comes together to allow the rocket to accelerate at an ever increasing rate until burnout.   
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Offline Action80

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Re: FE and ICBMs
« Reply #226 on: June 18, 2021, 09:49:01 PM »
Thanks WTF_S; 

To confirm, my contention is that the missile launches at a mass of 159,000 lbs, the majority of which is fuel, and all consumed within the initial, single, 5-minute, burn, which accelerates it on a high angle trajectory where y>x.
You contend that 159,000 lbs consisted of a, "majority of which is fuel," based on "what exactly?"

Total burn time = 5 minutes.
Any idea on the altitude and rate of travel achieved by the time of engine cut off? It is apparent you disagree with the 4500 km achieved at that time, contending an unpowered ballistic object can continue gaining a significant amount of altitude after impetus is removed.

Majority of the mass is fuel?  It's an aluminium tube with a 2000lb warhead at one end, and a rocket motor at the other.  You work it out.  What exactly do you think is inside the part between the motor and warhead?  Its a fuel tank or, for a solid fuel motor, containment for the fuel mass.
You have no idea then? The materials necessary would need to be of such strength as to withstand the forces sustained.

In other words, soda can aluminum would not fit the bill and not just any aluminum tube.   So now you are a stress engineer as well as a mathematician.  Good to know. My guess would be 2024 specification aluminium , or 7075 for high-stress areas.  Maybe some titanium to cope with heat stress.  But, as I said, I'm not a rocket scientist so its just a guess.  As for the soda cans; no idea again.  Beverage Packaging Engineer is another training course I never graduated from

Plus, where does the idea of solid fuel come from?  Many missiles use solid fuel.  Just mentioned it for completeness.  North Korea's SLBM in current development is speculated to have a solid fuel booster. 

Take a shot at a figure.   I think this is your area of expertise. 

Try UDMH weight per gallon, and high tensile strength aluminum and split it all up.
Altitude and velocity at engine shut-down? 

No idea. 
Thanks.   Some people might consider this a weakness.  Whilst it may be a precedent on the Internet if I don't know I'll tell you, rather than make up a number. 


Edit.   Sorry, I've just seen this in your response to Bob; 3000kph at T+5?  What part of left-field did that come from?  That's just a bit faster than Concorde with 100 passengers.  We are talking about a space-rocket FFS.  Do you have your own random number generator on these posts?   

Edit again.   I just worked out what you did; Bob's 250 km in 5 minutes, equates to a constant 3000 kph in your brain!  Brilliant.  You think it got to end of burn from a standing start at a constant 3000 kph!  This is absolutely mind-blowing stuff.  Was that a quadratic equation by the way?  Keep the posts coming, please; this is better than Big Bang Theory.
Are you unfamiliar with the concept of expressing average  velocity over time?

And I would appreciate it if you point to where I claimed quadratic functions apply to anything else other than trajectory calculations.
« Last Edit: June 18, 2021, 09:55:39 PM by Action80 »

Offline Action80

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Re: FE and ICBMs
« Reply #227 on: June 18, 2021, 10:03:19 PM »
Maybe A80 needs to ratchet up his math a bit to differential equations.  You have a rocket lifting off with a specific amount of thrust. Everything could be simple with a fixed amount of acceleration over a set time and you could do some quick calculations BUT; A rocket burns fuel at an enormous rate and the bulk of the rocket's mass is from fuel so every pound of fuel burned makes it easier for the rocket to accelerate.  This means that the rate of acceleration is accelerating.  The increase in speed per unit time (acceleration) will be much lower right after liftoff when the rocket is heavy with fuel.  Right before the rocket is empty of fuel and is much lighter, the acceleration rate peaks out.  The final velocity could be quite a bit higher than you might think.  Additionally as the rocket leaves the atmosphere the air drag decreases, and as the rocket gets further from the center of the earth the force of gravity decreases a bit as well.  Everything comes together to allow the rocket to accelerate at an ever increasing rate until burnout.   
Absolutely correct.
Bringing me back to this:
"   1) While serving as a US Merchant Marine officer aboard a cargo ship transiting between the Korean Peninsula and Japan there were numerous alarms and warnings going off on the bridge of our ship. 
   2)  Several broadcast messages to all ships at sea were received from the Japanese Coast Guard  authorities regarding the immanent and later the actual launch of a North Korean ICBM.
   3)  Since the North Koreans don't tell everyone in advance what is happening all we can do is wait.
   4)  The missile launch in question was at night.  Skies were clear and a missile was clearly seen traveling upwards then over the top (forward of the bow) of our ship."
So, to be perfectly clear, you saw the NK ICBM, engine ablaze, already making a clear arc across the night sky?

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Offline RonJ

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Re: FE and ICBMs
« Reply #228 on: June 19, 2021, 01:32:44 AM »
Maybe A80 needs to ratchet up his math a bit to differential equations.  You have a rocket lifting off with a specific amount of thrust. Everything could be simple with a fixed amount of acceleration over a set time and you could do some quick calculations BUT; A rocket burns fuel at an enormous rate and the bulk of the rocket's mass is from fuel so every pound of fuel burned makes it easier for the rocket to accelerate.  This means that the rate of acceleration is accelerating.  The increase in speed per unit time (acceleration) will be much lower right after liftoff when the rocket is heavy with fuel.  Right before the rocket is empty of fuel and is much lighter, the acceleration rate peaks out.  The final velocity could be quite a bit higher than you might think.  Additionally as the rocket leaves the atmosphere the air drag decreases, and as the rocket gets further from the center of the earth the force of gravity decreases a bit as well.  Everything comes together to allow the rocket to accelerate at an ever increasing rate until burnout.   
Absolutely correct.
Bringing me back to this:
"   1) While serving as a US Merchant Marine officer aboard a cargo ship transiting between the Korean Peninsula and Japan there were numerous alarms and warnings going off on the bridge of our ship.
   2)  Several broadcast messages to all ships at sea were received from the Japanese Coast Guard  authorities regarding the immanent and later the actual launch of a North Korean ICBM.
   3)  Since the North Koreans don't tell everyone in advance what is happening all we can do is wait.
   4)  The missile launch in question was at night.  Skies were clear and a missile was clearly seen traveling upwards then over the top (forward of the bow) of our ship."
So, to be perfectly clear, you saw the NK ICBM, engine ablaze, already making a clear arc across the night sky?
Yes, that's what we believed we saw.
You can lead flat earthers to the curve but you can't make them think!

Re: FE and ICBMs
« Reply #229 on: June 19, 2021, 09:44:51 AM »
@A80;

Are you unfamiliar with the concept of expressing average  velocity over time?

Are you familiar with the concepts of momentum and kinetic energy?  They are completely unrelated to average speed, so why quote that? 

And I would appreciate it if you point to where I claimed quadratic functions apply to anything else other than trajectory calculations.

The point was that, over the last dozen pages, you have mentioned "quadratic equations" a gazillion times, but not actually presented one of your own.  Are you familiar with the concept of irony or, like Kim's missile, has it gone clean over your head? 

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Online Rama Set

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Re: FE and ICBMs
« Reply #230 on: June 19, 2021, 01:11:08 PM »
While Total Lackey continues to be a contrarian let’s all remind ourselves that he agrees that rockets work. What exactly the problem with a large ballistic missile vs a smaller cruise missile is unclear.
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Offline SteelyBob

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Re: FE and ICBMs
« Reply #231 on: June 19, 2021, 01:21:14 PM »
Are you unfamiliar with the concept of expressing average  velocity over time?

Great - now we're getting somewhere, as you are at last explaining how you're getting to your erroneous statements. Average velocity would only work if the rocket's acceleration was constant. But it is far from constant. At launch, there is only a small amount of excess thrust over the weight of the rocket. But close to Hbo, the rocket is a lot lighter and yet still has the same thrust. So most of the accelerating happens in the latter stages of the burn. The Hwasong 15, for example, was estimated to have reached 7.17km/s at the end of its burn. At that velocity, it would take around 12 minutes to decelerate to 0 at 9.81ms-2

At which point you'll probably say 'so how come it flew for 50 minutes? Surely 12 x 2 = 24?'

Which then leads us to the other complicating factor that you aren't considering, which is the progressive reduction in g as you get further away from earth. At 4000km, for example, the ICBM would only experience a g of 3.7ms-2. That's why the calculations get complex very quickly - you've got variable mass and g, and a rotating planet.

Of course, I guess you disagree with the rotating round planet bit, and probably the reducing g bit as well. That's fine...but the burden then falls on you to explain what exactly did happen to the rocket if it flew for 50 odd minutes and only went 950km from the launch site, and how far it would be able to travel if it was launched at a shallower angle.


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Offline RonJ

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Re: FE and ICBMs
« Reply #232 on: June 19, 2021, 04:06:16 PM »
The fact that the rocket experiences less G forces at higher altitudes kind of blows up the UA argument here doesn't it?  It looks like the Wiki needs a whole lot of revisions.  Maybe someone could scam up a value for the Bishop Constant.
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Offline Dr Van Nostrand

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Re: FE and ICBMs
« Reply #233 on: June 19, 2021, 04:27:04 PM »
While Total Lackey continues to be a contrarian let’s all remind ourselves that he agrees that rockets work. What exactly the problem with a large ballistic missile vs a smaller cruise missile is unclear.

I think it's the 'intercontinental' aspect of the ICBM that he would have an issue with since he can't explain the size and positions of the major continents.
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Re: FE and ICBMs
« Reply #234 on: June 19, 2021, 06:04:22 PM »
I think the "missile" aspect is also a little challenging. 

He claims some experience of witnessing a Tomahawk;  "I cannot get into any particulars, except to state it was testing". 

A cruise missile, of course is fundamentally different to most other guided missiles.  A solid-fuel booster accelerates it to cruise speed, where a turbine engine takes over and propels it at a fairly constant sub-sonic speed for the next several hours under aerodynamic control to its target.  And the cruise engine keeps running right up to impact.  This was the design of the WW2 German V1, and every cruise missile since. 

I'm guessing he may also have difficulty with the concept of, for instance AAMs like AIM-9 Sidewinder, AIM-7 Sparrow and early AIM-32 ASRAAM, where the solid-fuel rocket motor accelerates it rapidly to multi-mach numbers within 2 or 3 seconds, and it glides the rest of the way to its target.  Judging from his posts, he seems to think that a (obviously fictional) ICBM motor should run until, at least, apogee. 

Offline Action80

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Re: FE and ICBMs
« Reply #235 on: June 21, 2021, 10:35:45 AM »
Are you unfamiliar with the concept of expressing average  velocity over time?

Great - now we're getting somewhere, as you are at last explaining how you're getting to your erroneous statements. Average velocity would only work if the rocket's acceleration was constant. But it is far from constant. At launch, there is only a small amount of excess thrust over the weight of the rocket. But close to Hbo, the rocket is a lot lighter and yet still has the same thrust. So most of the accelerating happens in the latter stages of the burn. The Hwasong 15, for example, was estimated to have reached 7.17km/s at the end of its burn. At that velocity, it would take around 12 minutes to decelerate to 0 at 9.81ms-2

At which point you'll probably say 'so how come it flew for 50 minutes? Surely 12 x 2 = 24?'

Which then leads us to the other complicating factor that you aren't considering, which is the progressive reduction in g as you get further away from earth. At 4000km, for example, the ICBM would only experience a g of 3.7ms-2. That's why the calculations get complex very quickly - you've got variable mass and g, and a rotating planet.

Of course, I guess you disagree with the rotating round planet bit, and probably the reducing g bit as well. That's fine...but the burden then falls on you to explain what exactly did happen to the rocket if it flew for 50 odd minutes and only went 950km from the launch site, and how far it would be able to travel if it was launched at a shallower angle.
I completely understand what you wrote.

I also completely understand that a rocket will completely accelerate until the end of its burn, at which point it will cease to continue the process of acceleration.

However, we are still at t+5, and we are still left with 250km altitude. and we are still left with the average rate of acceleration at 3,000 km/h.

So, splitting down to minutes, t+1, t+2,etc, given, for instance, the missile could obtain 1,000 km/h at t+1, 2,000 km/h at t+2, etc., up to 5,000 km/h, in order to average 3,000 km/h. Other values are possible over the span of 5 minutes, but the sum of these values/t cannot exceed 3,000 km/h.


So, how does a missile without engine burn, as you stated, accelerate to gain 4250 km in altitude within 48 minutes, fighting against g?
« Last Edit: June 21, 2021, 11:11:08 AM by Action80 »

Re: FE and ICBMs
« Reply #236 on: June 21, 2021, 11:08:10 AM »
You are completely missing the point.  Kinetic energy and momentum have nothing to do with average speed, and even less to do with "average acceleration".  The only relevant number is its instantaneous velocity at the time of engine shutdown.  Do you not understand anything about physics?  If the average acceleration equals 3000 kmph (what?), do you not understand that the RATE of acceleration has been increasing exponentially for the entire 5 minute burn due to the decreasing mass of the projectile? 

Sorry to appeal for assistance, but can anyone out there help him with this?

Offline Action80

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Re: FE and ICBMs
« Reply #237 on: June 21, 2021, 11:15:07 AM »
You are completely missing the point.  Kinetic energy and momentum have nothing to do with average speed, and even less to do with "average acceleration".  The only relevant number is its instantaneous velocity at the time of engine shutdown.  Do you not understand anything about physics?  If the average acceleration equals 3000 kmph (what?), do you not understand that the RATE of acceleration has been increasing exponentially for the entire 5 minute burn due to the decreasing mass of the projectile? 

Sorry to appeal for assistance, but can anyone out there help him with this?
I understand completely what you are writing.

If you are trying to claim the physics somehow does away with average rate of acceleration in this instance, however, that would be faulty.

In other words, you want to now claim that certain parameters of the entire launch, such as being in the right position at the right time, would be useless.

I understand that any set of acceleration values could be substituted at every minute, or even every second, or even every millisecond, of the 5 minute burn to an altitude of 250km, as long as the sum of the values/t = 3,000km/h.

So go ahead.

Provide a value at engine cut off that will suffice to meet the obvious requirement of 250km altitude at t+5, averaging 3,000 km/h over the 5 minute burn, and continue to accelerate the missile and cause the missile to achieve the span ranging from 250 km to 4500 km in less than 53 minutes.
« Last Edit: June 21, 2021, 11:46:00 AM by Action80 »

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Online Rama Set

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Re: FE and ICBMs
« Reply #238 on: June 21, 2021, 11:35:15 AM »
Do you mean 3,000 km/h2?
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Offline Action80

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Re: FE and ICBMs
« Reply #239 on: June 21, 2021, 11:38:47 AM »
Do you mean 3,000 km/h2?
5 minutes were spent from takeoff (0) to an altitude of 250 km.

So, no.

d=rt, requires no squaring of any values.
« Last Edit: June 21, 2021, 11:41:21 AM by Action80 »