A gift from heavens

[313baberali]

https://www.facebook.com/video.php?v=800394346739418

and helicopter scan by pakistan and chainese (abbotabad )

 

[amardeep mishra]

@HRK @The Deterrent @Nilgiri @amardeep mishra @Mrc

hi dear @shaheenmissile
@The Deterrent
Ok i take this opportunity to explain certain aspects of development of cruise missile.I will focus on aspects that might have been reverse engineered by pakistan(obviously with chinese assistance).
I will write my analysis in three broad categories-
1)Aerodynamics and Control(this also includes GNC)
2)Propulsion
3)Structure

** Aerodynamics and Control
Both are inseparable and require extensive wind tunnel tests.Since i come from control engineering background,this is particularly important from control design perspective. A control engineer is particularly interested in stability(see-em-alpha) and Control derivatives(see-em-delta) of an aerial vehicle. Coefficient of drag is also an important parameter that we might be interested in. Now i come to the instrumentation part of things i.e "measurement" of these parameters in a wind tunnel tests.You see,it is not always important to have just the wind tunnel,what is also very important is the capability of the wind tunnel to measure a host of parameters under various mach regimes(or for mach numbers it is designed). A chinese help in this area would have provided pakistan with much needed stability and control derivatives along with various other coefficients needed to design control system of babur cruise missile. I will also explain briefly how one can design control systems of a missile- especially a cruise missile-
(a) Firstly before commencing to design a control system you must have a MODEL- what we control engineers call- "aircraft model". This model is obtained by LINEARIZING a set of 8 simultaneous non linear and coupled differential equations around an EQUILIBRIUM POINT(in aerospace engineering this equilibrium point is known as TRIM CONDITION). After linearizing one would get something of this sort-
X'=AX+BU-------------------------------------------1....(here X' means X dot or time derivatives)
Y=CX+DU-------------------------------------------2
where X=(V,alpha,q,theta)'--- here (') means transpose of the 4x1 matrix
and U=(eta,de)------------ when i take X to be consisting of just 4 variables confined in X-Z plane then it is known as LONGITUDNAL STABILITY analysis. Once we have found out equation 1 and 2 around lets say a particular trim condition (lets assume level flight condition where flight path angle =0). Then we can can convert the above state space notation into frequency domain notation by using -
X(s)= (inverse(s*I-A))*B---------------------------3
where A is a 4x4 matrix and B is 4x2 matrix and I is identity matrix of order 4
equation 3 provides a very powerful insight into looking at an aerial vehicle. But there is a problem,and that is above equations 1&2 have been linearized around a fixed equilibrium point,but our aircraft flies under various trim conditions and our requirement thus becomes-
(i) finding all such possible trim conditions using BIFURCATION THEORY
(ii) linearizing the 8 non linear coupled equations around the equilibrium point obtain in step (i)

(b)Once we have obtained X(s) from step (a), we have essentially obtained transfer function between V,alpha,q,theta and control inputs eta and de(a MIMO system). Now we can bring the traditional control engineering concepts to bear and use various control engineering tools and techniques to design what is known as an ALTITUDE HOLD AUTOPILOT - one of the most fundamental requirements of cruise missile. Designing an altitude hold autopilot essentially means designing an attitude hold autopilot as well that sits inside the inner loop.
One can either use MATLAB or PYTHON to write a code for this.I use python because of itz general nature and good compatibility with linux

Pakistan must have used chinese off the shelf OBC for running this algorithms and various sensors like INS,etc

(2) Now comes the propulsion part,here chinese would have either developed a smaller turbojet by themselves or pakistan would have procured a ukrainian turbojet off the shelf.I am saying so because pakistan doesnt have any gas turbine research program and it takes decades to mature and to develop gas turbine industry ecosystem in the country.To be frank pakistan is still a GOOD TWO DECADES in even commencing their own gas turbine program

(3) This along with step (2) determine what would be the weight of the missile and hence the estimated range.Higher degree of composites mean a lighter missile which requires lesser fuel to produce propel it.One can very easily calculate range and endurance of a cruise missile provided we are given with-
(i) TSFC(thrust specific fuel consumption) of the engine- this figure tell you how much fuel (weight of the fuel in Newtons) needed to produce a sustained thrust of 1N
(ii) Lift is to Drag ratio
(iii) amount of fuel carried(in Newtons)
(iv) Empty weight of the missile(in N)

I suspect pakistan to not use composites because of the inherent requirement of complex winding machines that are currently not sold by western countries

TO be brutally honest,with the kind of research culture prevalent in pakistan,it would have taken them at least 2 decades to finally design and field a cruise missile but a lot of time was cut short thanks to this tomhawk and offcourse chinese labs!
PS- kindly note that i would gladly correct myself provided you furnish exact details of pakistani RESEARCH in babur program right from stability analysis/control design part to structures and propulsion!

 

[war&peace]

Yeah sure.Making a cruise missile is as easy as making ice cream. No wonder India is still struggling. I blame hot weather. Bye

Not just hot weather but the rape in the streets is also the reason since most of the scientists and engineers at DRDO are worried about their families back home.

 

[James David]

Its just a matter of time that Pakistan perfect cruise missile tech. They already got ballistic missiles for crying out loud! but that was the first time I have read that "THANK YOU USA!" as @Viper0011. said.. oh well..

 

[amardeep mishra]

Pretty sure Pakistan would have developed a cruise missile sooner or later, with or without this tomahawk.

A one time use turbofan is quite a simple thing to develop...no need to worry about huge TBC's, advanced superalloys and mitigating creep through SCB....and you can probably even physically iterate a few designs in short order if you put about a dozen competent mettalurgists and about the same number of material engineers and give them a few years (or use fewer and give them more time).

Then design the body and control surfaces, run the aerodynamic iterations and strap on a rocket booster. There you have it.

The tomahawk at most probably gave some shortcuts regarding ducting and I bet the Chinese were interested in the avionics for sure....but not a huge game changer like the original article is making it out to be.

To be honest,I never saw such a loose reply . I mean if designing a mature gas turbine was this easy then China wouldn't be needing Ukrainian help. The problem of acoustic instability is enough to give nightmares to even experienced engine designer. Not only that, the engine must have as low TSFC as possible for max possible range.
Offcourse, the requirements of "one time" smaller GT ain't as stringent and pressing as a turbofan that has way higher MTBO, but still one would need to make sure safe and reliable operation alongwith least possible TSFC and engine weight

 

[Nilgiri]

To be honest,I never saw such a loose reply . I mean if designing a mature gas turbine was this easy then China wouldn't be needing Ukrainian help. The problem of acoustic instability is enough to give nightmares to even experienced engine designer. Not only that, the engine must have as low TSFC as possible for max possible range.
Offcourse, the requirements of "one time" smaller GT ain't as stringent and pressing as a turbofan that has way higher MTBO, but still one would need to make sure safe and reliable operation alongwith least possible TSFC and engine weight

Agreed. I guess the choice of words sounded a little too unbalanced....but everyone automatically comes in to such a thread thinking its the hardest thing in the world...and the tomahawk was an oasis in a desert.

All I was saying that Pakistan (especially with Chinese help - who in turn have acquired international cooperation as well as you have mentioned) would have been able to acquire cruise missile platforms with or without the Tomahawk incident.

There is only so much you can reverse engineer from a design that falls on to your lap, there is still heavy grunt work a country has to do (especially if its already invested in a design iteration to start with)....that would not change if you didn't have the Tomahawk introduced halfway.

For any more detail one would have to have a very good background on where exactly the Pakistanis were in their cruise missile program when this all happened....was it just starting, did the already have stuff developed, how far along was that etc etc.....which I doubt anyone has any clear answers for.

 

[Windjammer]

Over the years, God has been kind to Pakistan, here was another gift from heavens.

 

[Tipu7]

Over the years, God has been kind to Pakistan, here was another gift from heavens.

Working ground for Barak missile???

 

[Guynextdoor2]

Lollzz they actually think you can 'study' a cruise missle and actually 'recreate' it. What did you recreate? The engines, the navigation and sensors? You can 'study' something but you can't recreate it- you don't have the infra to do it. PERIOD. And whether you like it or not there is much credence to the idea that far from you 'copying' the Tomahawk, yours is basically the Chinese cruise missile system.

The delusions some people live in- just AMAZING!!!

 

[Nilgiri]

Yeah sure.Making a cruise missile is as easy as making ice cream. No wonder India is still struggling. I blame hot weather. Bye

Intention was never to discredit Pakistani industrial capability and ingenuity. It is a solid accomplishment of Pakistan with or without Tomahawk tech....and whatever assistance you may or may not have gotten from China (I personally doubt its a pure chinese blueprint....but maybe I am wrong).

Pakistan has been in cruise missile specific development longer than India (given the more pressing requirement for Pakistan's nuclear deterrence) + have a strong ally/friend in China...so that's why you have a more mature operational design there.

 

[Guynextdoor2]

Yeah sure.Making a cruise missile is as easy as making ice cream. No wonder India is still struggling. I blame hot weather. Bye

That's why you haven't developed a cruise missile. Because it's complex tech that is out of your reach for now and foreseeable future.

 

[v9s]

That's why you haven't developed a cruise missile. Because it's complex tech that is out of your reach for now and foreseeable future.

You seem to misconstrue your opinion as fact.

 

[Guynextdoor2]

You seem to misconstrue your opinion as fact.

It's not 'opinion'- IT IS A FACT. There is a reason why the US develop TOmahawk's after they developed ballistic missile systems. And a reason why the RUssians struggled with it for long. You don't have the tech and the developmental levels. 'I looked millions of lines of GPS navigation code and developed one' and 'I measured the propulsion system using a scale and copied it' is just a ridiculous line to take.

Most likely what you did with the cruise was to hand it over to the Chinese.

 

[v9s]

It's not 'opinion'- IT IS A FACT. There is a reason why the US develop TOmahawk's after they developed ballistic missile systems. And a reason why the RUssians struggled with it for long. You don't have the tech and the developmental levels. 'I looked millions of lines of GPS navigation code and developed one' and 'I measured the propulsion system using a scale and copied it' is just a ridiculous line to take.

Most likely what you did with the cruise was to hand it over to the Chinese.

I'm not saying it was a completely indigenous effort. I'm pretty sure China helped.

But to say we had no input is just false - which is what you opined - and I replied to that.

 

[Guynextdoor2]

I'm not saying it was a completely indigenous effort. I'm pretty sure China helped.

But to say we had no input is just false - which is what you opined - and I replied to that.

I'm pretty sure that what you have is a Chinese missile. You don't do 'pieces' on this sort of stuff. I don't even know where you claim your production facility is. Plus, what exactly does finding a cruise system give anyone? You can look at it, maybe understand some characteristics. Primary engineering around this is so heavy that it's almost like building one from scratch.