Yasen submarines to be equipped with hypersonic missles with 1000km range

[500]

What makes you think 40N6 acts as ballistic missile?
What makes you think 40N6 dont use engines through all its flighttime?

I explained everything in #40. Read it again.

If Brahmos use "lofted trajectory to increase range" whats ur problem with 40N6 using any possible trajectory to increase its range?

It IS using ballistic lofted trajectory.

How much more BS you are going to make up?

So far its u who showed ignorance. You dont know even the most basic things about SAMs.

 

[zzzz]

I explained everything in #40. Read it again.

You said rubbish, not explained anything. If enemy target is flying at high altitude why would 40N6 would use any "ballistic trajectory"? do you know that flying very high (usually over 10km) will cost more fuel like flying very low? Why would 40N6 would use any "ballistic trajectory" instead of flying all the way toward target at optimal altitude?

It IS using ballistic lofted trajectory.

yeah? and you just claimed few posts ago that 40N6 and Bramos/Granit are so different because 40N6 is using "ballistic trajectory" do you even remember what did you say before?

So far its u who showed ignorance. You dont know even the most basic things about SAMs.

so far you posted BS in every of your post from first to last. discussing your knowledge of basic physics or SAMs is not even necessary.

 

[500]

You said rubbish, not explained anything. If enemy target is flying at high altitude why would 40N6 would use any "ballistic trajectory"?

Because its mosty effective. Why ballistic missiles use ballistic trajectory?

do you know that flying very high (usually over 10km) will cost more fuel like flying very low?

Why would 40N6 would use any "ballistic trajectory" instead of flying all the way toward target at optimal altitude?

How u else suppose to fly at 400 km if engine works for some 15 seconds?

yeah? and you just claimed few posts ago that 40N6 and Bramos/Granit are so different because 40N6 is using "ballistic trajectory" do you even remember what did you say before?

40N6 uses ballistic and lofted trajectory. It's engine shuts down after some 15 seconds and most of the time its flying using just its inertia.

Brahmos can use lofted rajectory its not ballistic since it uses its engine all the time.

 

[zzzz]

How u else suppose to fly at 400 km if engine works for some 15 seconds?

40N6 uses ballistic and lofted trajectory. It's engine shuts down after some 15 seconds and most of the time its flying using just its inertia.

Where did you get that its engine shuts down after 15 sec? source?

 

[Birbal]

That is exactly what is called as bullcrap and misrepresenting science to suit your agenda.

Please avoid the vitriol and stick to the scientific arguments.

An flying object requires 1g of vertical acceleration to remain steady.

Exactly.

If an object is moving in a vertical plane it has to accelerate more than 1g.The drag force is proportional to square of velocity and as the velocity of missile increases,drag force on missile increases.An hypersonic missile attains more velocity then a supersonic one.The missile has to exert more force to overcome air drag.Thrust requirement of a hypersonic missile is more not only because of higher acceleration that the missile would be have to partake but also because it has to overcome much more air drag compared to a supersonic missile.

In it's flight mode,a missile not only have to apply a force of vertical force of 9.8m[SUP]2[/SUP] to remain aloft but also has to apply an horizontal force whish is proportional to square of velocity

.Velocity of hypersonic missile is more than that of supersonic missile thus is a direct deduction from common sense that drag force being applied on an Hypersonic missile would be more than that of supersonic missile.Thus more thrust force would be required in case of hypersonic missile than that of supersonic one.

Only if you fly at the same altitude. Notice the density term in that drag formula? By flying at a higher altitude, the lower density compensates for the higher airspeed, which results in the same drag force. A higher altitude flight results in higher true airspeed for the same equivalent airspeed.

PS.Do not think that everyone else except you is stupid.You ignored a lot of variables in your assessment and tried to slip through using confusing jargons and self contradicting statements.

I formulated the problem in the standard way that an Aerospace Engineer does: using lift-to-drag ratio as the main variable. There's nothing confusing about that term.

LOL

Scramjet engine is an air breathing Engine,it is not a rocket engine that could escape atmosphere.It needs to remain within stratosphere thus air drag cannot be neglected.

And anyway even in vacuum,Hypersonic missile would require more fuel than supersonic missile thus having more weight.

Consider that a missile is fired in vacuum.Thus air drag is not acting on that missile.Now compare a supersonic missile with a hypersonic one for same range.

The thrust required in this case by a missile would have zero horizontal component and would be equal to weight of missile in vertical direction when it is in cruise mode.Thus both missiles are equal on this front.But for these missiles to attain their respective velocities which in case of hypersonic is higher than supersonic,the hypersonic missile would require higher acceleration for same amount of time or similar acceleration for extended time.If the missiles are using same engine,hypersonic missile would require more fuel thus increasing it's weight.

But we aren't firing in a vacuum and we're acting under the influence of gravity. The amount of energy required to accelerate to hypersonic speeds is miniscule compared to the amount of energy required to keep the missile from falling to earth during its flight.

The real problem with scramjet engine is that in order for scramjet engine to start,the body need to be travelling at supersonic velocity.Along with that a scramjet has lower thrust/weight Thus one always need to strap booster rocket to a missile in order to start scramjet.Efficiency of scramjet has to be compared with rockets as turbofan or turbojet engines are incapable of attaining hypersonic speed and scramjet engines come out with flying colours in that comparision because Scramjet engines does not have to carry oxidiser thus reducing their overall weight.

Scramjet - Wikipedia, the free encyclopedia

This is why scramjets aren't being used for aircraft. It just isn't practical. But it certainly would be quite feasible for a cruise missile to have a small first stage that accelerates it to supersonic speeds for the scramjet to start up.

The bigger problem is wether the decreased flight time due to increased speed will make up for the fall in fuel efficiency due to using a scramjet. Theoretically speaking, the two should cancel each other out. But in practice, it really depends. Certainly, the turbofan has been around a lot longer to be perfected, so the scramjet is at a disadvantage here.

 

[500]

Where did you get that its engine shuts down after 15 sec? source?

ÇÅÍÈÒÍÀß ÐÀÊÅÒÍÀß ÑÈÑÒÅÌÀ Ñ-300Ï [SA-10 GRUMBLE]

http://babelfish.yahoo.com/translat...300p/data_sam.htm&lp=ru_en&btnTrUrl=Translate

Only if you fly at the same altitude. Notice the density term in that drag formula? By flying at a higher altitude, the lower density compensates for the higher airspeed, which results in the same drag force. A higher altitude flight results in higher true airspeed for the same equivalent airspeed.

U dont need to be superfast to fly at high altitude, see U-2. Also V is in square in that formula. Thats why 18 ton U-2 has two times more range than 78 ton SR-71.

 

[anonymus]

Only if you fly at the same altitude. Notice the density term in that drag formula? By flying at a higher altitude, the lower density compensates for the higher airspeed, which results in the same drag force. A higher altitude flight results in higher true airspeed for the same equivalent airspeed.

SO.............

You are stating something which is apparent and was already encountered by me in my analysis.

This was your post ...........

Actually, it could be much more efficient by flying hypersonically in the outer atmosphere. Basically, the faster you fly, the shorter amount of time you need to stay in the air for any given distance. This means less fuel consumption.

Your assertion was that because hypersonic missiles are flying fast,they need to stay in air for shorter amount of time and thus fuel consumed would be less.

Now what i proved was that for same altitude a missile travelling at steady hypersonic velocity in cruise mode ( no acceleration hence no force required in vacuum situation) would be acted upon by far greater drag force than a supersonic one hence the missile would have to burn more fuel to overcome that drag force.

The difference in densities did not came into play as both missiles were supposed to be travelling at same altitude.It was to disprove that faster travelling missile requires less amount of fuel.

The post also violates first law of thermodynamics.It is equivalent to saying that if i drive faster than my car would consume less amount of fuel for same distance.

This is the formulae of Air drag

Only if you fly at the same altitude. Notice the density term in that drag formula? By flying at a higher altitude, the lower density compensates for the higher airspeed, which results in the same drag force. A higher altitude flight results in higher true airspeed for the same equivalent airspeed.

Probably you did not understand the meaning of the link you have provided......

A higher altitude does not result in higher truespeed.Truespeed is the speed that the body possesses.The difference if only in the term of equivalent speed.

Only if you fly at the same altitude. Notice the density term in that drag formula? By flying at a higher altitude, the lower density compensates for the higher airspeed, which results in the same drag force. A higher altitude flight results in higher true airspeed for the same equivalent airspeed.

Let's make a simple calculation which would put this thing to rest.


Formulaes:Earth Atmosphere Model - English Units

For troposphere

T = 59 - .00356 * h

p = 2116 * [(T + 459.7)/ 518.6]^5.256

r = p / [1718 * (T + 459.7)]

Now let's say a missile is cruising at an altitude of 100feet

T= 58.644[SUP]o[/SUP] F

p= 2110.5 lbs/ft[SUP]2[/SUP]

r= 0.00237 slugs/ft[SUP]3[/SUP] = 1.22 kg/m[SUP]3[/SUP]

For upper stratosphere

T = -205.05 + .00164 * h

p = 51.97 * [(T + 459.7)/ 389.98]^-11.388

r = p / [1718 * (T + 459.7)]

Let's say a missile is cruising at 83000 ft

T= -68.93 [SUP]o[/SUP]F

p= 50.786 lbs/ft[SUP]2[/SUP]

r= 0.00075648 slugs/ft[SUP]3[/SUP] = 0.38987 Kg/m[SUP]3[/SUP]

Now the formulae for drag has one power of density but square of velocity.

The ratio of density of air at ground level and upper stratosphere is Ground/Stratosphere = 31.32

Now let a supersonic cruise missile (Mach 1.2) is travelling at ground level while a hypersonic cruise missile is travelling through stratosphere (Mach 7)

Drag force on Supersonic/hypersonic = 31.32 X 1.2[SUP]2[/SUP] / 7[SUP]2[/SUP] = 0.92

ie a hypersonic missile cruising in upper stratosphere 1.08 times the drag faced by supersonic cruising at ground level and 34 times that faced by supersonic missile at same altitude.

In exact terms

C[SUB]D[/SUB] = 0.75 for a typical model rocket Drag coefficient - Wikipedia, the free encyclopedia

Let the missile has diameter of 1 m

so area = 0.758 m[SUP]2[/SUP]

For hypersonic (Mach 8)

F[SUB]d[/SUB]= 651201.2 Newton = 66449.1 KgF = equivalent of 66.45 tonnes.

Now a missile weights only 2-3 tonnes in the beginning.So the drag force acting on a hypersonic missile is 33 times that of its weight.ie Drag is not the force which is negligible.

But we aren't firing in a vacuum and we're acting under the influence of gravity. The amount of energy required to accelerate to hypersonic speeds is miniscule compared to the amount of energy required to keep the missile from falling to earth during its flight.

I gave example of vacuum as an ideal system where drag force = zero hence only vertical component of force is present.In reality both vertical and horizontal force is present.

The amount of energy required to keep a Hypersonic missile in sky is 30 times less than that which is required to maintain it's speed.and since the vertical force depends on weight of a missile which is in range of 2-3 tonnes and most of which is propellent which is used during boost phase,Fuel required for hypersonic missile is much more than that required for supersonic.

And most of the fuel is consumed by a rocket/missile in accelerating to hypersonic speeds.

This is why scramjets aren't being used for aircraft. It just isn't practical. But it certainly would be quite feasible for a cruise missile to have a small first stage that accelerates it to supersonic speeds for the scramjet to start up.

The bigger problem is wether the decreased flight time due to increased speed will make up for the fall in fuel efficiency due to using a scramjet. Theoretically speaking, the two should cancel each other out. But in practice, it really depends. Certainly, the turbofan has been around a lot longer to be perfected, so the scramjet is at a disadvantage here.

The efficiency of scramjet engine is worse than both rocket and turbojet engines.

Similarly efficiency of turboJet engines is less than that of piston cylinder engine.


If efficiency have been sole criterion than anyone would opt for radial piston engines for aviation.

But it is not so because there is a maximum speed limit up to which a engine could function.

A scramjet could not be compared to a turbojet as a turbojet could not achieve hypersonic velocities.Here Scramjet has to be compared with rockets which even though have greater efficiency tends to be bulkier as they need oxidiser.

Scramjet are also impractical to be used for satellite launch as they could not obtain orbital velocity even though they go hypersonic.For missiles also their ceiling limit is lower than that of rockets as they are air breathing.

 

[United]

Hi All i am so excited reading so much i feel like we must have our own forum PDF missile

anyways there is no exact formula for missile velocity, because it only affects range to a small extent. Missiles move at max velocity after a short acceleration period, so for practical purposes the velocity is roughly 95% of max.

Missile explosion velocity on the other hand affects damage and is not affected by missile velocity.

for moving target like a ship it depends on the size of the target.
The missile damage formula has been determined to be:
Damage = Base_Damage * MIN(MIN(sig/Er,1) , (Ev/Er * sig/vel)^(log(drf) / log(5.5)) )

Where
sig = ship's signature
vel = ship's velocity
Er = Explosion Radius of missile
Ev = Explosion Velocity of missile
drf = Damage Reduction Factor of missile


The relevant part of the missile damage formula is this:
(Ev/Er * sig/vel)
or
[explosion velocity] / [explosion radius] * [target signature radius] / [target velocity]

also

s(t) = (a(-1+e^(-t/(ma)))m+t)Vmax

where
s(t) = function for distance traveled over time t
t = time
m = mass / 1 000 000
a = inertia modifier
Vmax = maximum velocity

All in short Russians Rule in this no doubts.

 

[anonymus]

Missile explosion velocity on the other hand affects damage and is not affected by missile velocity.

What is the difference between missile velocity and missile explosion velocity.

Doesn't most of the missiles these days possess explosive warheads whith kinetic energy kill only existing in ASAT weapons.

 

[United]

Missile velocity would primarily depend on propellent and engine.Speed does play some role as it offers a drag force to a cruise missile.But most of the effort is exerted by a missile or any aerodynamic body to attain that velocity.



What is the difference between missile velocity and missile explosion velocity.

Doesn't most of the missiles these days possess explosive warheads whith kinetic energy kill only existing in ASAT weapons.

missile velocity >> the missile is not fast enought to hit the target, it will follow until its drive burns out and then disappear, with no damage inflicted.

missile explosion velocity >> If the target's velocity exceeds the explosion velocity, the target takes reduced damage (which scales as the difference between explosion velocity and target velocity increases). If the target's velocity great enough in comparison to the explosion velocity, the target will not take any damage at all (really a fraction of a percent of 1 point of damage). Please note that missiles do not inflict extra damage for the target being under the explosion velocity - anything moving slower than the explosion velocity simply takes full damage (before resists, of course). Also note that the target's actual velocity is used, not transversal velocity.

a very simple formula that can be used for estimating the performance of a missile. It goes like this:-

Change in Velocity (Delta V) = 10 x Specific Impulse x LN (initial weight / final weight) m/s

This assumes that all the fuel is used to get the missile as fast as possible and none is used to provide just enough thrust to sustain a given velocity. In otherwords, it assumes an all-boost motor not a boost sustain motor.

For example, let'a take a look at the AIM-120A AMRAAM which we have some decent info on...

Launch weight = 335 lbs (Published stats)
Motor weight = 156 lbs (WPU-6/B HTPB rocket motor weight as per Raytheon)
Approximate specific impulse = 245 seconds (typical of HTPB solid motors)
Approximate fuel fraction of motor = 85% (typical of robust aluminum cased aerospace rocket motors)

OK... if 85% of the motor's mass is the fuel, we have about 132 lbs of fuel in the AMRAAM-A -- roughly a 39.4% fuel fraction (sounds about right). So let's run the numbers...

Delta V = 10 x 245 x LN(335/(335-132)) = 1227 m/s

The formula predicts that the AMRAAM will go about 1227 m/s (~Mach 3.7) faster than it started. If it is launched at say Mach 1.5 it'll be going Mach 5.2. In reality the AMRAAM doesn't go that fast. The reason is that not all the fuel is used to get it as fast as possible. The AMRAAM's motor is a boost-sustain design. It is probably grained to take the weapon to abut Mach 2.5~2.8 faster than it started at (Mach 4+ in a typical Mach 1.5 release). The rest of the fuel is shaped to burn much more slowly to keep it's velocity at or near the achieved maximum out to a longer range before the motor burns out.

 

[mnd]

Its simply basic physics, no need to be a guru. With speed increase fuel consumption is growing exponentially. Thats why 7 ton Granit has range of 550 km and 3 ton new Brahmos/Oniks - only 300 km and bot missiles are only supersonic. Also Granit is way too big for Yasen class submarine.

Ha ha, schoolboy "physics" ))

To the point, that comparison is not correct. Export cruise/ballistic missiles are subject to restrictions in accordance with international treaty. Regardless of missile, they are restricted to a maximum range of 300 km, and warhead of 300 kg. So figures of Brahmos/Yakhont are not representative of performance potential of the missile, so no comparison. Domestic Oniks is not subject to these limitations, and has way superior characteristics, same as for example Club, same missile, but export version has 300 km range, domestic more than 2000 km ))

Of course, if you compare these export figures, to actual ones of domestic use, it does not match, but please, that is just common sense. This happens when you do not think, and ignore the subject.

 

[500]

Ha ha, schoolboy "physics" ))

To the point, that comparison is not correct. Export cruise/ballistic missiles are subject to restrictions in accordance with international treaty. Regardless of missile, they are restricted to a maximum range of 300 km, and warhead of 300 kg. So figures of Brahmos/Yakhont are not representative of performance potential of the missile, so no comparison. Domestic Oniks is not subject to these limitations, and has way superior characteristics, same as for example Club, same missile, but export version has 300 km range, domestic more than 2000 km ))

Of course, if you compare these export figures, to actual ones of domestic use, it does not match, but please, that is just common sense. This happens when you do not think, and ignore the subject.

Only schoolboy here is u. Granit is not export model.

 

[mnd]

Only schoolboy here is u. Granit is not export model.

That was what I said. You are comparing export figures to domestic, which is not correct comparison. Understand ?

On your technical "education" i will not further comment

 

[500]

That was what I said. You are comparing export figures to domestic, which is not correct comparison. Understand ?

On your technical "education" i will not further comment

Granit, which is not export model weights 7 tons (too big of Yasen), is not hypersonic and has range of 550 km. Hypersonic missile with range of 550 km would weight even much more.

 

[mnd]

Granit, which is not export model weights 7 tons (too big of Yasen), is not hypersonic and has range of 550 km. Hypersonic missile with range of 550 km would weight even much more.

Granit has nothing to do neither with yakhont (Brahmos), nor with yasen, so what is the point of bringing it here ?