Assalam O Alaikum from Rafeh

[aiman_hashmi.25]

to

 

[Muslim Warrior]

I am Rafeh. I am around 30 years old. Not married. I came from a set of diverse ethnicities from within Pakistan. I’ll just copy and past all that from my account approval page:

I was born and initially raised in Pakistan, but lived most of my life studying overseas (Europe, Australia). I have a lot of family members belonging to Pakistan military and other military research centers in Pakistan including at NESCOM, Kamra, Kahuta etc. .


Even though I came from a very influential family (or rather series of families) with MNAs still in parliament. I generally dislike politicians. Though I love Pakistan military and strongly support ISI and our other national security agencies.


I am an ethnic Pakistani Muslim with ancestry in all 4 provinces beginning with Kashmir (grandma from Kashmir valley, from the part still occupied), northern Punjab (mix Pothwari-hindkowan grandfather), Pashtun (mother), ethnic Baloch (mother's mother) with some distant relatives who are Sindhi (related to my Baloch grandmother). Some relatives and family friends are even from Chitral and Gilgit-Baltistan area. My family lives in Islamabad. As a result I am mostly into Pakistan and Pakistan alone.


For this reason Indians should NOT welcome me plus I have very strong pro-Kashmir freedom views. I don’t watch anything Indian, ever, no exceptions. That’s just who I am. I don’t mean to be rude. This is just an honest introduction.

Rest assured I will abide by the forum rules and I do not troll, ever.

As a person I am an extremely nationalist Pakistani and proud Muslim with love for all other Muslim majority nations.

Profession: I have a PhD in aerospace engineering but I see myself more akin to being a pure mathematician since my research involved and still involves learning and applying very abstract mathematical frameworks (e.g. non-smooth analysis.) to aircraft dynamics (earlier) and later on mathematically rigorous AI/Machine learning (with applications to mainly robotics e.g. agile locomotion etc). I also hold a degree in mechatronics engineering. As a mathematician in my free time, I study various other fields as well (i.e. physics, other branches of engineering etc). So I just thought, on occasion I will provide my own views on project Azm and other technical projects that are going on in Pakistan etc

Also I intend to return to Pakistan to open my own aerospace and robotics related high tech firm in around two years from now (may be few months more or less). As a result I closely monitor any development related to Pakistan’s manufacturing abilities and especially our ability to import any test or development equipment used in high tech industry. While the former aspect is improving fast, thanks to china, the later now finally has become a reality for the most part.

Earlier we could not import much. Just a while back, I remember my failure to import some test equipment from US to Pakistan. It was intended for smart material dynamics and control analysis related work (for research in swash-plate-less helicopter rotor blade pitch angle control mechanism design. i.e. smart helicopter rotor system among others.).

Now I have learned from my relatives in Pakistan, that we can pretty much import any test equipment from China (…thanks China….). China provides a manufacturing base, which can be used to built a higher layers of value added systems design and engineering within Pakistan.

A potential which is now increasingly being recognized in and outside of Pakistan. Pakistan military is already assessing this as an ongoing thing, and its potential for near future military related high technology design and development within Pakistan. I regularly discuss all this with friends and family within Pakistani military research centers and elsewhere.

For that to happen on full scale, we must let go any deep rooted inferiority complex and accept our own unique greatness (we are no less Aryans). We can match and outmatch anyone out there. Instead of catching up why not just start at the same level or better still higher , at least in theoretical modeling and analysis. Surety no one is stopping us mastering far more abstract mathematics than used by best of the best engineers or scientists out there. Especially since abstract mathematics is the mother of all supremacy, in all of science and advanced engineering.

In other words apart from theoretical research I genuinely see Pakistan as a place where now we can actually set up world class research and development centers and make our way up. So I would like to high light that potential of Pakistan as a country on this forum and elsewhere (e.g. as related to say Project Azm) . Despite all the problems, rise of Pakistan is inevitable.

Coming back to myself, in Pakistan my main hobbies are guns (hunting, shooting as a sport etc.) Overseas I generally like to travel a lot, I mean a lot . I speak several languages with varying degree of command including Russian, German, some Turkish, some Arabic, some Persian etc. So have friends from those regions as well as watch their movies. That pretty much summarizes my hobbies I guess.

P.S. the reason for this rather long introduction is that I want people to understand where I am coming from whenever I post a reply or a thread. Rather than allowing people to project their own reasoning behind my expressed views, I want them to clearly know in advance that this is who I am and hence my reasons for these kind of views. A full disclosure of sort for future reference.

Waalaikum Assalam

 

[Humble Analyst]

Once again thank you everyone for welcoming.

@war&peace, Brother I genuinely admire your efforts to share, educate and help other understand aspects of aerospace engineering. I will definitely contribute whatever i can. I do have a busy schedule, but whenever time permits I'll add my own views on technical topics. Even though you may be disappointed that people do not here show enough interest in your posts on technical matters. It may be because they are sometimes too technical for many.

Lets' admit it aerodynamics is quite challenging even for those who are studying it, especially since we don't have yet a coherent theory of aerodynamics. What I means, we don't have coherent set of mathematical equations that allows us to analytically calculate closed form expressions involving aerodynamics forces and moments on arbitrary aerodynamics surfaces. What we have in reality, are a bunch of approximate theories to deal with specific situations ranging form lifting line theories to theories dealing with bodies of revolutions, lifting surfaces, spectral theories etc.
The end result is we are forced to use some kind of numerical methods (i.e. CFD) even for relatively simple geometries or use things such as linearized theories to say calculate aerodynamics, stability, and control derivatives (which basically tell us how under the assumption of linearized aerodynamics, how changes in geometry, orientations, control surfaces etc, will effect aircraft aerodynamic, stability and control characteristics). That leads to empirical models (specific to each aircraft and each aircraft company), wind tunnel and CFD based look up tables for aerodynamic parameters (e.g. aerodynamic derivatives) giving us an estimate of aircraft aerodynamic behavior for each given altitude, control surfaces's position, deflections due to flexibility, external loads or missile launches and so on. Meaning we have to actually set up each situation that an aircraft may ever encounter in real life, either in wind tunnel and/or CFD to find out what what aircraft would do in what situation. That's very costly and takes years to complete. Not to mention requires hundreds of people. Though increasing accuracy of CFD is making things much faster every year now then the previous one.

One the other hand, if there was a unified aerodynamics theory, then we would plug those equations specialized for our particular aircraft under consideration on the place where you have forces and moments in the equations of dynamics (i.e. forces and moments in newton's equations, generalized forces in Lagrangian formulations etc.). One then would NEVER need a single wind tunnel test. We would solve those equations of motion (most likely numerically) and get aircraft dynamic behavior from start to finish as we please. Better still, we would plug those in our flight control laws and we would have a highly responsive flight control system in no time. Aircraft engineering would be as easy as developing a ground vehicle which many countries can do with some effort.

Not to mention we would then jointly solve those aerodynamics equations along with electrodynamics and get to have a stealth design far quicker, far better and with far less effort.

Unfortunately we don't have such coherent theory.

What I am trying to say is, it is quite challenging to discuss how in the absence of a unified general aerodynamics theory for arbitrary aircraft configurations, we can understand aerodynamics as a coherent set of conceptual and/or mathematical model. TO new comers and people outside of the aerospace engineering, it all looks like a big mess.

I am just trying to give a reason, why many people may not have contributed more to your post out of shear complexity that they represent.

War&Peace, brother, You are yourself an aerospace engineer so you can understand and appreciate all this complexity but not many others would find all this so interesting, especially since all seems too much information at times.

Still I agree, we should discuss all this in understandable terms, help each other understand where we need to learn more and your posts are perfect place to start that process.

However, it is not true that people from Pakistan's research organizations don't come here at all. I know for a fact they do come here (many relatives and friends do). They may even find something useful to look up after reading a post or two here. You never know.

This is called an open and positive mind.
I know a lot of guys who visit this forum and are aerospace or avionics engineers. Sometimes they just read or some are active too.

While everyone cannot get involved in an academic manner but sometimes the novice can bring up a good point or an idea.
Yes some people get emotional here and do not take disagreement well. But then there are others too so I come back and most of the times enjoy it.

 

[PDF]

if you can please read the intro and see if you can give a positive rating?
Thanks

No positive rating can be given in Members Club sub-forum. though, negatives are still open.

management does not encourage either.

Start a thread on technical discussion and make technical conversations/quality posts. I for one would love to learn from it.

NS equations

Ah! The famous Navier-Stokes Equations. Never grasped them while studying Fluid Mechanics. Assuming and simplifying all the time. Don't know how I passed those courses.

 

[Humble Analyst]

No positive rating can be given in Members Club sub-forum. though, negatives are still open.

Start a thread on technical discussion and make technical conversations/quality posts. I for one would love to learn from it.

Ah! The famous Navier-Stokes Equations. Never grasped them while studying Fluid Mechanics. Assuming and simplifying all the time. Don't know how I passed those courses.

For my information can you please elaborate what is a sub forum? Thanks

 

[PDF]

For my information can you please elaborate what is a sub forum? Thanks

My bad. Its not a sub-forum but a forum.
FYI, sub-forum example is given in picture below.

 

[Clearly]

Amazing intro! Im knackered otherwise would have given a longer response welcome to the club!

 

[Rafeh]

I am genuinely honored for all the very kind words and warm welcome. I am going to UAE due to a family emergency so I won't be able participate for a while. Still I am really grateful. I mean that. All of you take good care of yourself.

 

[TruthSeeker]

Welcome!!

Great introduction, thank you!

 

[Rafeh]

Ah! The famous Navier-Stokes Equations. Never grasped them while studying Fluid Mechanics. Assuming and simplifying all the time. Don't know how I passed those courses.

Brother the topic of Navier stokes equations started based on misunderstanding. It should not have been here in the introduction part. It was my fault.

I explained something else and could not clearly communicate it.

As a result, brother War&peace thought, I don't understand NS equations as a general model for fluid dynamics and perhaps confusing them with other aspects of aerodynamics. Rest assured, I do understand them. I was saying something completely different.

It was my fault as I was talking in bit too general terms and I failed to communicate the following:

Do we have currently an exact aerodynamics theory that directly uses Navier stokes equations as its underlying bases. The answer is NO. We first have to solve these navier stokes equations to say calculate pressure distributions. WE then integrate those pressure distribution on say an aircraft to get all the forces and moments acting on it. That's what I was saying. Aerodynamics here refers our ability to directly derive forces and moments (i.e. lift and drag expressions) which is still not fully understood for a general flight vehicles (e.g. for say helicopter rotors system etc).

Do we have currently approximate aerodynamics theories that directly uses Navier stokes equations as their underlying bases. The answer is Yes.

The whole thing was a misunderstanding thanks to my own condensed writing. The point is you should not think that they are somehow that mysterious or that complex.

I can assure you one thing though, they are very easy once you work with them for a while. Their mathematical nature is complex since they are nonlinear partial differential equations. But most engineers don't study those aspects (e.g. those involving nonlinear functional analysis). Engineers use numerical solutions which become routine once we use them for a while, or they they study their simpler forms with associated analytic solutions obtained under highly simplifying situations. if we neglect viscosity etc. they reduce to Euler's equations. Even inverse solution techniques involving navier stokes equations (solution techniques that help us design optimum aerodynamics shapes) can be learned with determined approach in few weeks or months (depends on how far you want to go).

So please I don't want you to think they are too mysterious. They are not. In essence they are fluid dynamics version of F=ma. You know that already. Though off course they require much more care.

The point is during undergraduate years, we all struggle. But later when academic pressure is gone, we all can relearn with much more clarity what seemed to be so hard while studying at the uni.

So please don't be discouraged by any initial difficulty. I still recall my own difficulty in a very abstract mathematical field called theory of sheaves during my doctoral years . I initially thought I will never get it, and now I am expert at it. We all had those difficulties for one topic or the other. They go away with perseverance. Partly things seems hard since no one properly explained them to us in way that begins with the basics (our basics) and then taking it further from then on.

I am leaving for sydney today. From there, I am going to UAE (to a hospital there). My mother is unwell. Naturally I am really disturbed. SO I won't be here on this forum for unspecified time. For now this my last post. We might have to take her to europe though before eventually returning to Pakistan. I will be back insha-Allah, once my mother's health improves.

 

[PDF]

Brother the topic of Navier stokes equations started based on misunderstanding. It should not have been here in the introduction part. It was my fault.

I explained something else and could not clearly communicate it.

As a result, brother War&peace thought, I don't understand NS equations as a general model for fluid dynamics and perhaps confusing them with other aspects of aerodynamics. Rest assured, I do understand them. I was saying something completely different.

It was my fault as I was talking in bit too general terms and I failed to communicate the following:

Do we have currently an exact aerodynamics theory that directly uses Navier stokes equations as its underlying bases. The answer is NO. We first have to solve these navier stokes equations to say calculate pressure distributions. WE then integrate those pressure distribution on say an aircraft to get all the forces and moments acting on it. That's what I was saying. Aerodynamics here refers our ability to directly derive forces and moments (i.e. lift and drag expressions) which is still not fully understood for a general flight vehicles (e.g. for say helicopter rotors system etc).

Do we have currently approximate aerodynamics theories that directly uses Navier stokes equations as their underlying bases. The answer is Yes.

The whole thing was a misunderstanding thanks to my own condensed writing. The point is you should not think that they are somehow that mysterious or that complex.

I can assure you one thing though, they are very easy once you work with them for a while. Their mathematical nature is complex since they are nonlinear partial differential equations. But most engineers don't study those aspects (e.g. those involving nonlinear functional analysis). Engineers use numerical solutions which become routine once we use them for a while, or they they study their simpler forms with associated analytic solutions obtained under highly simplifying situations. if we neglect viscosity etc. they reduce to Euler's equations. Even inverse solution techniques involving navier stokes equations (solution techniques that help us design optimum aerodynamics shapes) can be learned with determined approach in few weeks or months (depends on how far you want to go).

So please I don't want you to think they are too mysterious. They are not. In essence they are fluid dynamics version of F=ma. You know that already. Though off course they require much more care.

The point is during undergraduate years, we all struggle. But later when academic pressure is gone, we all can relearn with much more clarity what seemed to be so hard while studying at the uni.

So please don't be discouraged by any initial difficulty. I still recall my own difficulty in a very abstract mathematical field called theory of sheaves during my doctoral years . I initially thought I will never get it, and now I am expert at it. We all had those difficulties for one topic or the other. They go away with perseverance. Partly things seems hard since no one properly explained them to us in way that begins with the basics (our basics) and then taking it further from then on.

I am leaving for sydney today. From there, I am going to UAE (to a hospital there). My mother is unwell. Naturally I am really disturbed. SO I won't be here on this forum for unspecified time. For now this my last post. We might have to take her to europe though before eventually returning to Pakistan. I will be back insha-Allah, once my mother's health improves.

May Allah grant back her health and a speedy recovery! You take care of yourself and your mother.