DRDO, PSU and Private Defence Sector News

[Kuntal]

Hey @Kuntal willing to model K4 ?

It will surely grab headlines but i am kind of afraid we could get into trouble.

We could do for private distribution and put a disclaimer that the design concept is imaginery lol

I need a fair understanding of the k4 in order to make a 3d model. Because there is no picture available in public domain.

Sent from my SM-M307F using Tapatalk

 

[porky_kicker]

in k4 gas generator is fitted in the missile and thrusters are also present at the same spot whereas in western slbm gas generators are present in submarine tubes itself .this shows that k4 has very odd design well it also has some advantages that launch tubes need to carry small gas generators and it also adds a bit of thrust.

Gas generator for propelling the missile is at the bottom of the canister / silo.

The gas generator on interstage 2/3 is for creating a gas bubble , same function as a cavitator on the nose of the Soviet missile.

Both are completely different

And i could be wrong about the gas generator for the bubble on interstage 2/3.

It could be possible that the small vents are for something else and the 2 pairs of main thrusters on interstage 2/3 fire just after the missile clears the silo and does the dual function of creating the bubble for transition through water and then propelling the missile out of the water into the atmosphere upto a safe altitude for the 1st stage to fire.

This one sounds less complicated and more plausible.

Anyways
All these is my personal opinion , don't take it as the truth. Some are based on pieced on info , but some are hypothesis.

Info on kfour in open domain is almost zero.

 

[porky_kicker]

I need a fair understanding of the k4 in order to make a 3d model. Because there is no picture available in public domain.

Sent from my SM-M307F using Tapatalk

I will contact you later on .............

 

[porky_kicker]

notice that Soviet missile uses both tractor rocket attached to the nose fairing like k15 as well as thrusters present at interstage like k4 so it uses mix technique of both k15 and k4 very unique.

I don't see any interstage thrusters on the Soviet missile . Where ?

 

[fire starter]

I don't see any interstage thrusters on the Soviet missile . Where ?

yup only tractor rocket is used which afterwards got separated like in k15. what about thrusters can they be fitted at bottom or does western icbm have those.

 

[fire starter]

I don't see any interstage thrusters on the Soviet missile . Where ?

look at French missile how smoothly it comes out without thrusters or gas bubble generators on interstage what do u want to say. is cavitation alternative to gas encapsulation.

 

[porky_kicker]

BDL AMOGHA 3 test fire pic

They are using old flame launcher for testing the 3rd gen AMOGHA 3 ATGM

Hopefully they include a modern FCS in the final product.

 

[porky_kicker]

yup only tractor rocket is used which afterwards got separated like in k15. what about thrusters can they be fitted at bottom or does western icbm have those.

I think you meant using 1st stage itself like in US french SLBM after it gets ejected out of water.

I think drdo is not confident or does not have the tech to do so. The missile after ejecting from water is for some seconds in zero gravity like situation ( free falling ) when the 1 st stage fires to get the missile flying . You might have noticed the missile starting trajectory is not straight.

This is complex tech , drdo might try it in K5

One needs to learn to crawl before walking

 

[porky_kicker]

It looks like the early VEM ATGM

 

[fire starter]

I think you meant using 1st stage itself like in US french SLBM after it gets ejected out of water.

I think drdo is not confident or does not have the tech to do so. The missile after ejecting from water is for some seconds in zero gravity like situation ( free falling ) when the 1 st stage fires to get the missile flying . You might have noticed the missile starting trajectory is not straight.

This is complex tech , drdo might try it in K5

One needs to learn to crawl before walking

can u tell me about the launching mechanism of western slbm.

 

[porky_kicker]

can u tell me about the launching mechanism of western slbm.

Bro i am myself not informed , each missile has it own specific way of launching and specific design characteristics to aid in ejection and then flight.

Open source info is scare for obvious reasons, so one is forced to speculate

Eg

French m51 is suspected to have a single vent at top of nose cap connected to gas generator, as the gas/steam generator at the bottom of canister pushes the missile upwards like a cannon ball , the layer of gas from top of nose creates a bubble , which allows the missile to travel with greater momentum enough to jump clear of the water when 1st stage fires. Later the single vent gives way to a extendable aerospike.


The American trident seems to be sealed tight into its canister overpressured with nitrogen , it uses flash charges to vaporise water into steam so that the resulting impulse pushes the missile like a bullet , the accompanying nitrogen gas layer creates a bubble of sort and helps in reduced drag thus the missile is launched clear out of water where 1st stage fires.

I am not sure about all these because no sure info exists on the same

 

[porky_kicker]

I think i will have to rethink everything about kfour which i wrote previously

 

[fire starter]

I think i will have to rethink everything about kfour which i wrote previously

so k5 and k6 will use French way most probably.

 

[happylion]

The nose ring tractor is a cavitator. Some Russian SLBM's have them. We have chosen that method for K4 Like the R39 Shtil. It is NOT via an interstage There are different methods to launch an SLBM

 

[Pret]

I believe upto 3 mirvs , given the shaping of the nose of kfour.


And

View attachment 42018

Explain this................

That's an upper-stage attitude-control/velocity-trim module. It's used right below the reentry vehicle (single warhead), in MIRVed missiles, it's built right into the payload-bus.
It's not Russian BTW, those words are written in English XD

 

[Chinmoy]

The answer is thrust termination device .

Drdo took some time to perfect it

Solid fuel rocket motors cannot stop combustion ( producing thrust ) once started, they employ an alternative means to negate the thrust . This is done via thrust termination device included with advanced solid fuel rocket motors , which allows to negate the ongoing thrust being produced inorder to allow staging or separation of PBV to occur safely and importantly control range and corresponding trajectory . More more details try Google.


And IMO those vents in Agni 3 releasing smoke during launch are probably connected to thrust termination devices, the moment when the pyro devices are set off.

Eg

It the target is within the reach of 1st stage of A3 , the 2nd stage is made redundant by firing the thrust termination devices on 2nd stage during launch , hence IMO the smoke coming out of the vents adjacent to the 2nd stage .

When the first stage burns out and gets separated during flight , the 2nd stage fires as standard operating procedure but since the thrust termination devices have already being activated the combustion of solid fuel starts but does not produce thrust since the gases produced during combustion starts escaping via the thrust termination vents , thus producing reverse or retro thrust , which allows for safer seperation of unneeded 2nd stage from PBV. All these happens in a matter of few seconds. Thus missile can fly in a lower controlled trajectory or conversely trajectory can be controlled as per requirements of range . This is an advanced and complicated flight control system mastered by very few countries. Implications of same for developing SLBMs are huge. Remember rumours of Agni 3 being used to test SLBM technologies.

Google to understand , without knowledge of thrust termination device and vent , difficult to comprehend what i wrote.

As usual use your own discretion , i cannot guarantee i am correct IMO.

Just one word would sum up the whole essay.......... STOF.

We have tested it time and again in various platform of ours.

 

[porky_kicker]

It's not Russian BTW, those words are written in English XD

What made you think it is written in Russian in the first place ?

Wonder what KELTEC means in Russian :biggrin2:

 

[Chinmoy]

The American trident seems to be sealed tight into its canister overpressured with nitrogen , it uses flash charges to vaporise water into steam so that the resulting impulse pushes the missile like a bullet , the accompanying nitrogen gas layer creates a bubble of sort and helps in reduced drag thus the missile is launched clear out of water where 1st stage fires.

It doesn't use flash charge, but a rocket motor. Rocket motor is attached to a tank with water in it. The motor is used to vaporize the water which in turn creates pressure in the launch tube.


Interestingly you yourself shared somewhat similar diagram here.

 

[porky_kicker]

Just one word would sum up the whole essay.......... STOF.

We have tested it time and again in various platform of ours.

............................................
What is stof ?

 

[Chinmoy]

............................................
What is stof ?

Short Time Of Flight.

The tests we did for depressed trajectory were for those. We could use even a 5k range missile to attack a much nearer target at say 1.5 or 2k km. We don't need to launch them in a lofted trajectory for that.

Interestingly, even the K4 was tested for the same last time.