AMCA - Advanced Medium Combat Aircraft

Bhartiya Sainik said:

CONGRATS Mr. POST GRAD + RESEARCH FELLOW + TEACHER !
YOU TRIED TO
> ACT LIKE SLEF-PROCLAIMED OTHERS' REPRESENTATIVE
> BUT INSULT EVERYONE'S CAPABILITY FORGETTING EVERYONE HAS SAME PCM TILL CLASS-10
> STALL THIS FORUM BY DISCOURAGING & CONTROLLING OTHERS
> FIND EXCUSE NOT TO SHARE BASIC INFO
> BUT PANIC PEOPLE BY GIVING COMPLEX MATHS
& IN THE PROCESS ACTUALLY INSULTED YOURSELF.
YOU KNOW EVERY MEMBER'S QUALIFICATION, PROFFESSION, EXPERIENCE, DESIGNATION?
THE SCIENCE OPTING STUDENTS WENT TO PET, KCET, IIT-JEE, COACHING CLASSES. WE ALL WERE TAUGHT SHORTCUTS TO SOLVE TRIGONOMETRIC, CALCULUS, MATRICES EQUATIONS IN EXAMS. SOME PREPARED FOR GATE, GRE, CAT/MAT, etc ALSO. TODAY WE DON'T NEED TO SOLVE THINGS ON PAPER BUT WE CAN UNDERSTAND THE FINAL EXPRESSION ANSWER - NUMERATOR & DENOMINATOR.
MANY MEMBERS have to manage office, house, family then find time to come here for time-pass. Like i said before, I only share & ask for basic calculations, graphs, diagrams & you are reacting as if someone demanded your kidneys, citing personal problems & excuses of time, motivation. You want to take personal responsibility to represent everyone? But you are preemptively doubting everybody's comprehension, qualification, experience.
A POST GRAD + RESEARCH FELLOW + TEACHER does not react like this.
Some of our college seniors joined back MTech, PhD & taught us. They were always cool with our querries. Where they didn't know they said it honestly.
I humbly introduced myself to be middle aged(40+), low IQ, senior IT engineer in role of system admin & tech support. I may not be PG/PhD holder but B.E. in Computers should be enough to discuss with M.Tech. DO YOU UNDERSTAND COMPUTER SCIENCE ENGINEERING SUBJECTS?
Today any person like me would naturally have every type & level of well qualified people in his/her social circle. But people with aeronautical interest are rare. For fear of troll nobody reveals their Linked-In & social media IDs.
So let me say this -

You could be Post Grad + teacher + Research fellow.
OR
You could be high school/college kid unable to give answers but panicking & copy-pasting hi-fi equations when asked for basic info, which all of us can copy paste.

Either ways, YOUR PRESENTATION, FORMAL COMMUNICATION, LEADERSHIP SKILLS ARE PATHETIC. YOU ASSUME TOO MUCH ABOUT OTHERS. STOP INSULTING & TRYING TO CONTROL OTHERS. IF YOU DON'T APPRECIATE US, WHY SHOULD WE APPRECIATE YOU?

DON'T ENDANGER REPUTATION OF THIS BRAND NEW WEBSITE.
OTHERWISE TELL ADMINS TO DELETE ALL R&D NEWS, EVERYTHING ABOVE MIDDLE SCHOOL LEVEL.
View attachment 3111


Detail doesn't mean straight up to level of highest level of hardcore maths, I never shared or asked for it.
Your time & motivation is your personal problem. Ignore & move on.
Forums contain people of all level, you cant stop anyone to discuss at a particular level.
Like i said, in every college, office also, people are tasked sometimes for presentations to audience, subjected to interaction.


Who asked you for all that? Sharing some basic parts from Wikipedia & Google Search means doing PG & PhD on this Forum?
You 1st share basic calculations, graphs, diagrams, then we will tell you what we understood.


PRESENTATION SKILLS INCLUDE SIMPLIFICATION
So far you replied only GENERIC text with zero attachments, like typing from cellphone. It is only now you posted some info that too straight highest level of maths. You behave in extremities, either generic or hi-fi level.
I did not reply you with anything advanced & deep. Did you see me copy pasting OR asking you for the CALCULUS, MATRICES, HIGHER ORDER ALGEBRIC EQUATIONS part from Wikipedia, Google search? If you don't have capability to acertain other's level & maintain their level in a conversation then how do you manage a team? Leave team, how do you handle meeting people in any situation?
View attachment 3143

Gentle reminder - we are not people's representatives. Forums contain people of all age, qualification, experience. Everybody till class-10 learned basic PCM, calculus, vectors, etc.
You give your best what people ask. People can simply skip & ignore what they don't like or understand. They can even say that they don't get it, like i said i hate advanced PCM.


You are not scaring anyone. We all watch documentaries on TV & Youtube which mention such things. We simply ignore the hard parts.


This is easy to understand. 2D vectors was taught to everyone in Class 9/10. I have already seen this Velocity Triangle & mentioned about stator vane control few times.





I have seen Youtube videos on air flow control by vanes also. The following video is much simpler.

View attachment 3114

I know about the velocity triangle. I could have shared it.
View attachment 3106
But you don't need to know if EVERYONE can understand, just the person(s) whom you are discussing with.


Science grads in school & engineering grads like me can attempt to understand what we like, if we like. You think only you understand terms like "isentropic", "isobaric", "adiabatic", etc?
I do understand the diagram above.
I saw many diagrams on wikipedia.
View attachment 3107

View attachment 3104



Where? When? Why don't you use "quote" functionality to remention if required?

We are not talking about stationary gas turbines for electricity generation on land.
We are not talking about Turbo prop
We are not talking about Turboshaft
Don't confuse people.
Mention the Efficiency equation or formula for low BPR military Turbofan, that's it.
Do you see any Defence enthusiasts channel talking about Efficiency (may be Tarmak Media House)? The following is a very short list. Now, I don't follow any channel strictly. But before covid-19 i had a huge list of websites - formal & casual.

View attachment 3116


WHO KNOWS WHAT YOU ARE BUT EITHER WAYS YOUR FORMAL COMMUNICATION SKILL IS PATHETIC.
And let me remind you AGAIN that since a decade now I am middle aged Sr. IT Engineer + SME + Project Trainer + Team Lead for UG+PG people. We are not R&D guys but out part is also important. Don't belittle others indirectly.
Today, there are many IIT+IIM or equivalent people. Everybody top to bottom including CEOs, CFOs, CIOs, CTOs, etc is expendable.


Depends on individual member. I don't need it.
1st you share the minimum diagrams, graphs, specific basic specs, basic calculations, then we will see further.


That's your personal problem.
You can refer to Communication trainers, Career Counselors.
You can attend seminars on Group discussion & Personal Interview.
You can watch Youtube videos also.
You can ask your trusted experienced people in your circle that with any kind of misbehavior you may get rejected in interviews or fired after being hired. Everywhere there are HR policies for code of conduct.

------------------------------------------------------------------------
We should continue to share what we know IN SIMPLIFIED WAY. Some will like, some will ignore, that's how forum works, nothing to worry about. But none of us should presume & misbehave with others.

Click to expand...

[did read all that though ]

125mm_Smoothbore said:

View attachment 3144
[did read all that though ]

Click to expand...

I postponed it I think I will never read that in future.

125mm_Smoothbore said:

View attachment 3144
[did read all that though ]

Click to expand...

Satish Sharma Ji said:

I postponed it I think I will never read that in future.

Click to expand...

World is in grey shades.
Share what you can
Comprehend what you can
Ignore what you can't get
Move on

125mm_Smoothbore said:

View attachment 3144
[did read all that though ]

Click to expand...

THe user used to have the same style on DFI also, For my sanity I have him on the ignore list on both sites.

SwordOfDarkness said:

THe user used to have the same style on DFI also, For my sanity I have him on the ignore list on both sites.

Click to expand...

LOL!, evidently you don't seem to ignore & maintain your sanity.
Your style WAS & IS still philosophy, politics, etc.
But it is ok. 5 fingers are different.

scholar of war said:

Brother, just relax.

I have told multiple times that I neither have time nor motivation to go into details.
I can give you all the resources needed but you have to study them yourself.


Spoon feeding stops at UG level courses. When we start studying at PG level, we have to do everything ourselves. In PhD, supervisors do not even provide resources, students have to do everything themselves.

Higher-level study is all about independent work.

Advanced fluid mechanics is a subject that requires a high level of understanding of mathematics.

Below is the NS equation in incompressible, non-conservative form with the assumption that viscosity is constant.

View attachment 3086
These are famous Navier -Stokes equations developed in the 1840s. If you can solve these equations analytically you will get a million dollar prize.

The above equation is the very basic needed to understand Advanced fluid mechanics.

now below we have written the same equation in simplified non-dimensional form.



View attachment 3087

below is the basic 2 equation standard KE model used to numerically solve these equation.

View attachment 3093

Many people in this forum do not have a technical background and forget about a degree in mechanical or electrical engineering, and you are asking to explain post graduate - level topics in detail.


I am not scaring anyone but if you can't understand these equations then you will never be able to understand the lift, drag, aerodynamics etc. The people who developed models to solve these equations are the current generation's best. Spallart who developed the spallart-allmaras model of turbulence works at Boeing. Menter who developed the SST K-omega model works at Ansys.





View attachment 3090
Above are the velocity triangles of an axial flow compressor with a rotor and stator. I don't even know if anyone can understand this or not.


View attachment 3096

The above is a simplified cycle showing the difference between the ideal and actual Brayton cycle. You have no idea about Brayton cycle or the difference between the actual or ideal cycle.

You do not understand the concept of efficiency. I have explained to you the scientific definition of efficiency yet you decide to ignore that.

Total efficiency or overall efficiency does exist.
Efficiency overall = efficiency 1 X efficiency 2 X efficiency 3 ......................x efficiency n

for ex >>>
Brayton cycle or gas turbines are also used as stationary gas turbines for electricity generation on land.

The overall efficiency is = cycle efficiency X mechanical efficiency X generator efficiency


another example is when a gas turbine is used for a turboshaft or turboprop where output is given in kilowatts and you can easily calculate efficiency by dividing output power by input power.
Input power is the calorific value of the fuel.

Efficiency = shaft power / ( mass flow rate fuel X calorific value of fuel)

It's not that I don't like to teach people but I don't like to teach advanced concepts when people have no idea of basics.

And let me remind you my primary job is doing research and sometimes teaching PG students.


I will help anyone and provide guidance to those who want to learn advanced fluid mechanics, computational fluid dynamics, turbulence modelling, advanced engineering mathematics etc and I will share videos, codes, ebooks etc if someone needs them but in the end, people have to learn these topics themselves.


And sorry if my post sounds rude but sometime I do get irritated.

Click to expand...

too complexe for me. My maths are too old...

Bhartiya Sainik said:

CONGRATS Mr. POST GRAD + RESEARCH FELLOW + TEACHER !
YOU TRIED TO
> ACT LIKE SLEF-PROCLAIMED OTHERS' REPRESENTATIVE
> BUT INSULT EVERYONE'S CAPABILITY FORGETTING EVERYONE HAS SAME PCM TILL CLASS-10
> STALL THIS FORUM BY DISCOURAGING & CONTROLLING OTHERS
> FIND EXCUSE NOT TO SHARE BASIC INFO
> BUT PANIC PEOPLE BY GIVING COMPLEX MATHS
& IN THE PROCESS ACTUALLY INSULTED YOURSELF.
YOU KNOW EVERY MEMBER'S QUALIFICATION, PROFFESSION, EXPERIENCE, DESIGNATION?
THE SCIENCE OPTING STUDENTS WENT TO PET, KCET, IIT-JEE, COACHING CLASSES. WE ALL WERE TAUGHT SHORTCUTS TO SOLVE TRIGONOMETRIC, CALCULUS, MATRICES EQUATIONS IN EXAMS. SOME PREPARED FOR GATE, GRE, CAT/MAT, etc ALSO. TODAY WE DON'T NEED TO SOLVE THINGS ON PAPER BUT WE CAN UNDERSTAND THE FINAL EXPRESSION ANSWER - NUMERATOR & DENOMINATOR.
MANY MEMBERS have to manage office, house, family then find time to come here for time-pass. Like i said before, I only share & ask for basic calculations, graphs, diagrams & you are reacting as if someone demanded your kidneys, citing personal problems & excuses of time, motivation. You want to take personal responsibility to represent everyone? But you are preemptively doubting everybody's comprehension, qualification, experience.
A POST GRAD + RESEARCH FELLOW + TEACHER does not react like this.
Some of our college seniors joined back MTech, PhD & taught us. They were always cool with our querries. Where they didn't know they said it honestly.
I humbly introduced myself to be middle aged(40+), low IQ, senior IT engineer in role of system admin & tech support. I may not be PG/PhD holder but B.E. in Computers should be enough to discuss with M.Tech. DO YOU UNDERSTAND COMPUTER SCIENCE ENGINEERING SUBJECTS?
Today any person like me would naturally have every type & level of well qualified people in his/her social circle. But people with aeronautical interest are rare. For fear of troll nobody reveals their Linked-In & social media IDs.
So let me say this -

You could be Post Grad + teacher + Research fellow.
OR
You could be high school/college kid unable to give answers but panicking & copy-pasting hi-fi equations when asked for basic info, which all of us can copy paste.

Either ways, YOUR PRESENTATION, FORMAL COMMUNICATION, LEADERSHIP SKILLS ARE PATHETIC. YOU ASSUME TOO MUCH ABOUT OTHERS. STOP INSULTING & TRYING TO CONTROL OTHERS. IF YOU DON'T APPRECIATE US, WHY SHOULD WE APPRECIATE YOU?

DON'T ENDANGER REPUTATION OF THIS BRAND NEW WEBSITE.
OTHERWISE TELL ADMINS TO DELETE ALL R&D NEWS, EVERYTHING ABOVE MIDDLE SCHOOL LEVEL.
View attachment 3111


Detail doesn't mean straight up to level of highest level of hardcore maths, I never shared or asked for it.
Your time & motivation is your personal problem. Ignore & move on.
Forums contain people of all level, you cant stop anyone to discuss at a particular level.
Like i said, in every college, office also, people are tasked sometimes for presentations to audience, subjected to interaction.


Who asked you for all that? Sharing some basic parts from Wikipedia & Google Search means doing PG & PhD on this Forum?
You 1st share basic calculations, graphs, diagrams, then we will tell you what we understood.


PRESENTATION SKILLS INCLUDE SIMPLIFICATION
So far you replied only GENERIC text with zero attachments, like typing from cellphone. It is only now you posted some info that too straight highest level of maths. You behave in extremities, either generic or hi-fi level.
I did not reply you with anything advanced & deep. Did you see me copy pasting OR asking you for the CALCULUS, MATRICES, HIGHER ORDER ALGEBRIC EQUATIONS part from Wikipedia, Google search? If you don't have capability to acertain other's level & maintain their level in a conversation then how do you manage a team? Leave team, how do you handle meeting people in any situation?
View attachment 3143

Gentle reminder - we are not people's representatives. Forums contain people of all age, qualification, experience. Everybody till class-10 learned basic PCM, calculus, vectors, etc.
You give your best what people ask. People can simply skip & ignore what they don't like or understand. They can even say that they don't get it, like i said i hate advanced PCM.


You are not scaring anyone. We all watch documentaries on TV & Youtube which mention such things. We simply ignore the hard parts.


This is easy to understand. 2D vectors was taught to everyone in Class 9/10. I have already seen this Velocity Triangle & mentioned about stator vane control few times.





I have seen Youtube videos on air flow control by vanes also. The following video is much simpler.

View attachment 3114

I know about the velocity triangle. I could have shared it.
View attachment 3106
But you don't need to know if EVERYONE can understand, just the person(s) whom you are discussing with.


Science grads in school & engineering grads like me can attempt to understand what we like, if we like. You think only you understand terms like "isentropic", "isobaric", "adiabatic", etc?
I do understand the diagram above.
I saw many diagrams on wikipedia.
View attachment 3107

View attachment 3104



Where? When? Why don't you use "quote" functionality to remention if required?

We are not talking about stationary gas turbines for electricity generation on land.
We are not talking about Turbo prop
We are not talking about Turboshaft
Don't confuse people.
Mention the Efficiency equation or formula for low BPR military Turbofan, that's it.
Do you see any Defence enthusiasts channel talking about Efficiency (may be Tarmak Media House)? The following is a very short list. Now, I don't follow any channel strictly. But before covid-19 i had a huge list of websites - formal & casual.

View attachment 3116


WHO KNOWS WHAT YOU ARE BUT EITHER WAYS YOUR FORMAL COMMUNICATION SKILL IS PATHETIC.
And let me remind you AGAIN that since a decade now I am middle aged Sr. IT Engineer + SME + Project Trainer + Team Lead for UG+PG people. We are not R&D guys but out part is also important. Don't belittle others indirectly.
Today, there are many IIT+IIM or equivalent people. Everybody top to bottom including CEOs, CFOs, CIOs, CTOs, etc is expendable.


Depends on individual member. I don't need it.
1st you share the minimum diagrams, graphs, specific basic specs, basic calculations, then we will see further.


That's your personal problem.
You can refer to Communication trainers, Career Counselors.
You can attend seminars on Group discussion & Personal Interview.
You can watch Youtube videos also.
You can ask your trusted experienced people in your circle that with any kind of misbehavior you may get rejected in interviews or fired after being hired. Everywhere there are HR policies for code of conduct.

------------------------------------------------------------------------
We should continue to share what we know IN SIMPLIFIED WAY. Some will like, some will ignore, that's how forum works, nothing to worry about. But none of us should presume & misbehave with others.

Click to expand...

Sayonara! Peace!

Bhartiya Sainik said:

POLARIZATON ALERT
We wan't latest TECHNOLOGY weapons but no toleration of BASIC diagrams, graphs, addition, subtraction, multiplication, division.
Lots of prejudice, presumptions.
What's the use of forums?
What's the use of teaching algebra, basic calculus, matrices, PCM till class-10?

Click to expand...

I have pow tolerance for your multi emoji rest it's plain theory, read most of it, just make it precise

Bhartiya Sainik said:

CONGRATS Mr. POST GRAD + RESEARCH FELLOW + TEACHER !
YOU TRIED TO
> ACT LIKE SLEF-PROCLAIMED OTHERS' REPRESENTATIVE
> BUT INSULT EVERYONE'S CAPABILITY FORGETTING EVERYONE HAS SAME PCM TILL CLASS-10
> STALL THIS FORUM BY DISCOURAGING & CONTROLLING OTHERS
> FIND EXCUSE NOT TO SHARE BASIC INFO
> BUT PANIC PEOPLE BY GIVING COMPLEX MATHS
& IN THE PROCESS ACTUALLY INSULTED YOURSELF.
YOU KNOW EVERY MEMBER'S QUALIFICATION, PROFFESSION, EXPERIENCE, DESIGNATION?
THE SCIENCE OPTING STUDENTS WENT TO PET, KCET, IIT-JEE, COACHING CLASSES. WE ALL WERE TAUGHT SHORTCUTS TO SOLVE TRIGONOMETRIC, CALCULUS, MATRICES EQUATIONS IN EXAMS. SOME PREPARED FOR GATE, GRE, CAT/MAT, etc ALSO. TODAY WE DON'T NEED TO SOLVE THINGS ON PAPER BUT WE CAN UNDERSTAND THE FINAL EXPRESSION ANSWER - NUMERATOR & DENOMINATOR.
MANY MEMBERS have to manage office, house, family then find time to come here for time-pass. Like i said before, I only share & ask for basic calculations, graphs, diagrams & you are reacting as if someone demanded your kidneys, citing personal problems & excuses of time, motivation. You want to take personal responsibility to represent everyone? But you are preemptively doubting everybody's comprehension, qualification, experience.
A POST GRAD + RESEARCH FELLOW + TEACHER does not react like this.
Some of our college seniors joined back MTech, PhD & taught us. They were always cool with our querries. Where they didn't know they said it honestly.
I humbly introduced myself to be middle aged(40+), low IQ, senior IT engineer in role of system admin & tech support. I may not be PG/PhD holder but B.E. in Computers should be enough to discuss with M.Tech. DO YOU UNDERSTAND COMPUTER SCIENCE ENGINEERING SUBJECTS?
Today any person like me would naturally have every type & level of well qualified people in his/her social circle. But people with aeronautical interest are rare. For fear of troll nobody reveals their Linked-In & social media IDs.
So let me say this -

You could be Post Grad + teacher + Research fellow.
OR
You could be high school/college kid unable to give answers but panicking & copy-pasting hi-fi equations when asked for basic info, which all of us can copy paste.

Either ways, YOUR PRESENTATION, FORMAL COMMUNICATION, LEADERSHIP SKILLS ARE PATHETIC. YOU ASSUME TOO MUCH ABOUT OTHERS. STOP INSULTING & TRYING TO CONTROL OTHERS. IF YOU DON'T APPRECIATE US, WHY SHOULD WE APPRECIATE YOU?

DON'T ENDANGER REPUTATION OF THIS BRAND NEW WEBSITE.
OTHERWISE TELL ADMINS TO DELETE ALL R&D NEWS, EVERYTHING ABOVE MIDDLE SCHOOL LEVEL.
View attachment 3111


Detail doesn't mean straight up to level of highest level of hardcore maths, I never shared or asked for it.
Your time & motivation is your personal problem. Ignore & move on.
Forums contain people of all level, you cant stop anyone to discuss at a particular level.
Like i said, in every college, office also, people are tasked sometimes for presentations to audience, subjected to interaction.


Who asked you for all that? Sharing some basic parts from Wikipedia & Google Search means doing PG & PhD on this Forum?
You 1st share basic calculations, graphs, diagrams, then we will tell you what we understood.


PRESENTATION SKILLS INCLUDE SIMPLIFICATION
So far you replied only GENERIC text with zero attachments, like typing from cellphone. It is only now you posted some info that too straight highest level of maths. You behave in extremities, either generic or hi-fi level.
I did not reply you with anything advanced & deep. Did you see me copy pasting OR asking you for the CALCULUS, MATRICES, HIGHER ORDER ALGEBRIC EQUATIONS part from Wikipedia, Google search? If you don't have capability to acertain other's level & maintain their level in a conversation then how do you manage a team? Leave team, how do you handle meeting people in any situation?
View attachment 3143

Gentle reminder - we are not people's representatives. Forums contain people of all age, qualification, experience. Everybody till class-10 learned basic PCM, calculus, vectors, etc.
You give your best what people ask. People can simply skip & ignore what they don't like or understand. They can even say that they don't get it, like i said i hate advanced PCM.


You are not scaring anyone. We all watch documentaries on TV & Youtube which mention such things. We simply ignore the hard parts.


This is easy to understand. 2D vectors was taught to everyone in Class 9/10. I have already seen this Velocity Triangle & mentioned about stator vane control few times.





I have seen Youtube videos on air flow control by vanes also. The following video is much simpler.

View attachment 3114

I know about the velocity triangle. I could have shared it.
View attachment 3106
But you don't need to know if EVERYONE can understand, just the person(s) whom you are discussing with.


Science grads in school & engineering grads like me can attempt to understand what we like, if we like. You think only you understand terms like "isentropic", "isobaric", "adiabatic", etc?
I do understand the diagram above.
I saw many diagrams on wikipedia.
View attachment 3107

View attachment 3104



Where? When? Why don't you use "quote" functionality to remention if required?

We are not talking about stationary gas turbines for electricity generation on land.
We are not talking about Turbo prop
We are not talking about Turboshaft
Don't confuse people.
Mention the Efficiency equation or formula for low BPR military Turbofan, that's it.
Do you see any Defence enthusiasts channel talking about Efficiency (may be Tarmak Media House)? The following is a very short list. Now, I don't follow any channel strictly. But before covid-19 i had a huge list of websites - formal & casual.

View attachment 3116


WHO KNOWS WHAT YOU ARE BUT EITHER WAYS YOUR FORMAL COMMUNICATION SKILL IS PATHETIC.
And let me remind you AGAIN that since a decade now I am middle aged Sr. IT Engineer + SME + Project Trainer + Team Lead for UG+PG people. We are not R&D guys but out part is also important. Don't belittle others indirectly.
Today, there are many IIT+IIM or equivalent people. Everybody top to bottom including CEOs, CFOs, CIOs, CTOs, etc is expendable.


Depends on individual member. I don't need it.
1st you share the minimum diagrams, graphs, specific basic specs, basic calculations, then we will see further.


That's your personal problem.
You can refer to Communication trainers, Career Counselors.
You can attend seminars on Group discussion & Personal Interview.
You can watch Youtube videos also.
You can ask your trusted experienced people in your circle that with any kind of misbehavior you may get rejected in interviews or fired after being hired. Everywhere there are HR policies for code of conduct.

------------------------------------------------------------------------
We should continue to share what we know IN SIMPLIFIED WAY. Some will like, some will ignore, that's how forum works, nothing to worry about. But none of us should presume & misbehave with others.

Click to expand...

Can't you ask for informed advice and be grateful when someone spends time doing that for you?

Spitfire IX said:

Can't you ask for informed advice and be grateful when someone spends time doing that for you?

Click to expand...

> Advice is taken when we are making something, some goal or objective is there.
> None of us know anything about eachother - age, qualification, profession, experience. Anybody can pretend to be anybody, copy pasting the simplest to most complex thing.
> Nobody here is doing anything special for anybody personally.
> There is nothing to be greatful to anyone on a time-pass casual technical forum.
> I never asked or expected members to be greatful to me when i shared so many pics, diagrams, basic calculations which took me few days to search, sometimes few weeks, & compile into a post.

Few images to understand efficiency, sfc, tsfc etc.
Efficiency of turbofan do exists.
Only reason no one talks about it is that we do not use shaft power output of turbojet or turbofan engine. The primary use is to produce thrust so better way for gauging engine is to use TSFC but efficiency still is the primary criteria to design any engine of any cycle. Every text book explains efficiency as well as provides formula to calculate jet engine (brayton cycle) efficiency.

Please don't quote me, reply me, ask doubt etc.

I don't have enough braincells.

Bhartiya Sainik said:

If 2 cities are say 800 Kms apart.
1) A subsonic jet takes X gallons/litres/Kg of fuel flying at 800Km/hr takes 1hr (Flight/Fuel-burn time).
X amount fuel burnt in 60mins. Fuel burning rate = X/60 per minute
2) If a SuCr jet with new secret engine flying at 1,600 Km/hr taking 30mins, burns same X amount of fuel but quicker, is it a bad thing?
X amount fuel burnt in 30mins. The fuel burning rate is 2(X/60) per minute.
Distance travelled by both jets is same 800 Km
Fuel consumed by both jets is same X.
Subsonic jet took TWICE time than SuCr jet.
The above is a theoretical example but scientists & engineers are working to get as close to it as possible. No engine is IDEAL, there are verious kinds of losses - thermal, mechanical, friction, sonic drag, etc.
We need to see the engine SFC data from credible source, figures or graph on fuel consumption at different speeds & altitudes.

Click to expand...

Great Idea for a scenario but at the end of the day it's a theoretical one. That said, I think you agree with me that the maximum range can only be achieved in subsonic flights rather than supersonic flights because:
>You didn't refute my earlier point with any calculation, any diagram, any equation, any flight manual or any other material.
>That is why the example that you gave of two aircraft of which one is in subsonic flight and the other in supersonic flight was a theoretical one because I have yet to find an example of an aircraft that can travel twice the speed "X" to cover distance "Y" with the same amount of fuel consumed "Z" .
>You, I & basically every engineer/scientist working in the development of aircraft engines wish that there were jet-engines that could allow a plane to travel faster, in less time using the same amount of fuel to cover same distance that it would cover if it travelled slower and took more time to reach it's destination. But currently no such engine exists from what I know. That is why you gave a hypothetical example as said before, and you wrote "The above is a theoretical example but scientists & engineers are working to get as close to it as possible.". I think we will get there one day or rather very close to it, and I hope we do make an engine like this.
This Christmas I will wish to Santa Claus for such a jet-engine, let's do the same, Santa Claus will surely grant our wishes!
I am happy though that both you and I have an agreement here on this topic of which flight (Supersonic v/s Subsonic) is more fuel efficient in terms of distance and time.

Bhartiya Sainik said:

We are not even talking about Afterburners. It is not part of Supercruise.

Click to expand...

I wasn't talking about supercruise in the part you have quoted. What I had written in that paragraph of my post had little to nothing to do with the concept of supercruise, at least not directly. It was something (Just a point I thought would be relevant to the discussion between you & me) that I had added to prove my point to others (not you) that you can't have the same level of fuel/distance/efficiency from supersonic flight in comparison to subsonic flight.
That is why when I wrote that paragraph, I started it with:
"One thing I don't know if everyone is aware of or not...."
Sorry, I should have made it a bit easier for everyone to understand what I was trying to say, I apologise for any confusion that I may have created, if any.
And this is not originally my claim, this same point was raised by an engineer in one of his posts on erstwhile forum DFI and I repeated it here. He is a very knowledgeable person and shares good technical data and information in his posts, I learnt a lot from him. And I have already written about it earlier, read the first part of my quote to you. I apologise if I may have unnecessarily repeated something that you already know and understand.

Bhartiya Sainik said:

As calculated & said earlier, F-35A's airframe T/W ratio with 50% fuel & IWB-AA load is 0.72 while that of F-22 is 0.92+
Its wing is shorter, with lower sweep angle, creates more drag. Its fuselage is a lifting body.
AMCA will be 12 tons empty, F-35A is 13.3 tons empty.
Fixing the wing will be enormous cost. All they can do is engine upgrade which they have started.

Click to expand...

If I get the free time, I will do some calculations of my own and post them here and cross check with your calculations. Do not have anything else to add here. I do not have any idea about aerodynamics, at least not the more complex parts of it so I will not talk about something I do not understand.
I will see some online material that I can read (if it is an article) or watch (if it's a video) to understand more about what is a lifting body, which fuselage design causes more drag & etc.

Bhartiya Sainik said:

You missed my reply on Marketing.

Click to expand...

I will go through it for sure when I get the time to read the discussion between you and the other members on this thread.

Bhartiya Sainik said:

Check my previous post on Efficiency, Performance, Thrust, I/p -> Process -> O/p

Click to expand...

I will surely look into your previous posts to try & understand whatever I can, but I wish to exit this discussion for now, I neither have the time nor qualification for debating/discussing topics that are out of my grasp with guys like you who have probably spent more time in I.T sector than I have lived on this planet. This is to not say that I want to stop reading the discussions here altogether. I only discuss what I can & not what I cannot.

• Everything I discuss & post here is based on my current understanding of science, technology etc which my K-12 curriculum has given me + reading a lot of online articles as well helps to learn a little out of the box too.
• I can do basic calculations such as multiplication, division, addition, subtraction to help me ascertain certain things such as how what would be the MTOW of a plane with so and so payload but that is about it, I cannot go into deep understanding of the equations posted here by some of the members, I can at the most write them down, enter the values and get the solution, that is Input => Output. Other than that, I have no interest in advanced mathematics.
• I have already given an introduction of myself in this thread. Post in thread 'New Members' Introduction' https://defenceforumbharat.com/threads/new-members-introduction.4/post-1105

Have a great day ahead. Hope to learn a lot from guys like you. Sayanora.

Neil (नील/Нил) said:

Great Idea for a scenario but at the end of the day it's a theoretical one. That said, I think you agree with me that the maximum range can only be achieved in subsonic flights rather than supersonic flights because:
>You didn't refute my earlier point with any calculation, any diagram, any equation, any flight manual or any other material.
>That is why the example that you gave of two aircraft of which one is in subsonic flight and the other in supersonic flight was a theoretical one because I have yet to find an example of an aircraft that can travel twice the speed "X" to cover distance "Y" with the same amount of fuel consumed "Z" .
>You, I & basically every engineer/scientist working in the development of aircraft engines wish that there were jet-engines that could allow a plane to travel faster, in less time using the same amount of fuel to cover same distance that it would cover if it travelled slower and took more time to reach it's destination. But currently no such engine exists from what I know. That is why you gave a hypothetical example as said before, and you wrote "The above is a theoretical example but scientists & engineers are working to get as close to it as possible.". I think we will get there one day or rather very close to it, and I hope we do make an engine like this.
This Christmas I will wish to Santa Claus for such a jet-engine, let's do the same, Santa Claus will surely grant our wishes!
I am happy though that both you and I have an agreement here on this topic of which flight (Supersonic v/s Subsonic) is more fuel efficient in terms of distance and time.

I wasn't talking about supercruise in the part you have quoted. What I had written in that paragraph of my post had little to nothing to do with the concept of supercruise, at least not directly. It was something (Just a point I thought would be relevant to the discussion between you & me) that I had added to prove my point to others (not you) that you can't have the same level of fuel/distance/efficiency from supersonic flight in comparison to subsonic flight.
That is why when I wrote that paragraph, I started it with:
"One thing I don't know if everyone is aware of or not...."
Sorry, I should have made it a bit easier for everyone to understand what I was trying to say, I apologise for any confusion that I may have created, if any.
And this is not originally my claim, this same point was raised by an engineer in one of his posts on erstwhile forum DFI and I repeated it here. He is a very knowledgeable person and shares good technical data and information in his posts, I learnt a lot from him. And I have already written about it earlier, read the first part of my quote to you. I apologise if I may have unnecessarily repeated something that you already know and understand.

If I get the free time, I will do some calculations of my own and post them here and cross check with your calculations. Do not have anything else to add here. I do not have any idea about aerodynamics, at least not the more complex parts of it so I will not talk about something I do not understand.
I will see some online material that I can read (if it is an article) or watch (if it's a video) to understand more about what is a lifting body, which fuselage design causes more drag & etc.

I will go through it for sure when I get the time to read the discussion between you and the other members on this thread.

I will surely look into your previous posts to try & understand whatever I can, but I wish to exit this discussion for now, I neither have the time nor qualification for debating/discussing topics that are out of my grasp with guys like you who have probably spent more time in I.T sector than I have lived on this planet. This is to not say that I want to stop reading the discussions here altogether. I only discuss what I can & not what I cannot.

• Everything I discuss & post here is based on my current understanding of science, technology etc which my K-12 curriculum has given me + reading a lot of online articles as well helps to learn a little out of the box too.
• I can do basic calculations such as multiplication, division, addition, subtraction to help me ascertain certain things such as how what would be the MTOW of a plane with so and so payload but that is about it, I cannot go into deep understanding of the equations posted here by some of the members, I can at the most write them down, enter the values and get the solution, that is Input => Output. Other than that, I have no interest in advanced mathematics.
• I have already given an introduction of myself in this thread. Post in thread 'New Members' Introduction' https://defenceforumbharat.com/threads/new-members-introduction.4/post-1105

Have a great day ahead. Hope to learn a lot from guys like you. Sayanora.

Click to expand...

let's analyze this idea with a little bit of physics.

Work = force X displacement
work is equivalent to energy.

energy by the first plane =W= F X D

according to second law of thermodynamics only some part of fuel or input energy can be converted into output work

now we assume the second plane is traveling at twice the speed facing twice air resistance so the force needed will also be twice.

energy needed by the second plane = 2F X D = 2W


so for the same distance travelling at a fast speed energy needed is twice. Which resultS in twice the amount of fuel.

CASE 0
In current-gen technology where efficiency falls after Mach 1 this feat is not possible

Case I
So let's assume we are living in an ideal world where the engine is running at constant efficiency at all speeds this feet is again not theoretically possible.

Case II
now let's assume we have a wonderful variable cycle engine where efficiency increases on increasing speed this may become a reality one day. But as far as simple physics go we may reach close but high unlike to achieve this.

"SUPER-FLANKER", good to see you here. Nice strategy to stay passive.

Neil (नील/Нил) said:

Great Idea for a scenario but at the end of the day it's a theoretical one. That said, I think you agree with me that the maximum range can only be achieved in subsonic flights rather than supersonic flights because:
>You didn't refute my earlier point with any calculation, any diagram, any equation, any flight manual or any other material.
>That is why the example that you gave of two aircraft of which one is in subsonic flight and the other in supersonic flight was a theoretical one because I have yet to find an example of an aircraft that can travel twice the speed "X" to cover distance "Y" with the same amount of fuel consumed "Z" .
>You, I & basically every engineer/scientist working in the development of aircraft engines wish that there were jet-engines that could allow a plane to travel faster, in less time using the same amount of fuel to cover same distance that it would cover if it travelled slower and took more time to reach it's destination. But currently no such engine exists from what I know. That is why you gave a hypothetical example as said before, and you wrote "The above is a theoretical example but scientists & engineers are working to get as close to it as possible.". I think we will get there one day or rather very close to it, and I hope we do make an engine like this.
This Christmas I will wish to Santa Claus for such a jet-engine, let's do the same, Santa Claus will surely grant our wishes!
I am happy though that both you and I have an agreement here on this topic of which flight (Supersonic v/s Subsonic) is more fuel efficient in terms of distance and time.

Click to expand...

Most probably it is right that Subsonic fuel efficiency is better than Supercruise, but it is better to confirm with SFC data for same jet, say F-22, at M 1.8 & M 0.8, IDK if it is avialbale to public.
The thing to note is - there is always some compromise & losses. What matters is objective. For SR-71, fuel consumption with repeated AA refuelling was worth for CIA/USAF bcoz Spy-Sats were not available. Today the case is opposite.
What is more important for USAF with F-22? F119 SFC is lowest 17 gm/KN/s, so they may not worry much about fuel if the VLO F-22 shoots down all its adversaries.
Mach 1.8 - 17 gm/KN/s - 100 % throttle - 116 KN+
Mach 0.9 - ?? gm/KN/s - ?? % throttle - ?? KN
And don't forget, to launch JDAM, SDB, etc, higher altitude & faster launch speed will increase range. f-22 will do it perhaps w/o revealing its IIRS but other jets will use Reheat revealing their IRS.

Neil (नील/Нил) said:

I wasn't talking about supercruise in the part you have quoted. What I had written in that paragraph of my post had little to nothing to do with the concept of supercruise, at least not directly. It was something (Just a point I thought would be relevant to the discussion between you & me) that I had added to prove my point to others (not you) that you can't have the same level of fuel/distance/efficiency from supersonic flight in comparison to subsonic flight.
That is why when I wrote that paragraph, I started it with:
"One thing I don't know if everyone is aware of or not...."
Sorry, I should have made it a bit easier for everyone to understand what I was trying to say, I apologise for any confusion that I may have created, if any.

Click to expand...

Ok, why sorry, apologize?

Neil (नील/Нил) said:

And this is not originally my claim, this same point was raised by an engineer in one of his posts on erstwhile forum DFI and I repeated it here. He is a very knowledgeable person and shares good technical data and information in his posts, I learnt a lot from him. And I have already written about it earlier, read the first part of my quote to you. I apologise if I may have unnecessarily repeated something that you already know and understand.

Click to expand...

Did i say something on DFI? Feel free to take screenshots of my DFI posts, but use it constructively.
We have to see what exactly we said earlier in what context, etc. Our knowledge & understanding improves with time.

Neil (नील/Нил) said:

If I get the free time, I will do some calculations of my own and post them here and cross check with your calculations. Do not have anything else to add here. I do not have any idea about aerodynamics, at least not the more complex parts of it so I will not talk about something I do not understand.
I will see some online material that I can read (if it is an article) or watch (if it's a video) to understand more about what is a lifting body, which fuselage design causes more drag & etc.

Click to expand...

In my limited knowledge from Discovery Channel documentaries since 1990s, Lifting body fuselage are of 2 types - air pushes the front belly of fuselage up; & parts of the fuselage longitudinal cross section like LERX are like that of a wing, creating a low pressure on top. I think MiG-29, Su-27/3X have this kind of LERX.

Neil (नील/Нил) said:

I will go through it for sure when I get the time to read the discussion between you and the other members on this thread.
I will surely look into your previous posts to try & understand whatever I can, but I wish to exit this discussion for now, I neither have the time nor qualification for debating/discussing topics that are out of my grasp with guys like you who have probably spent more time in I.T sector than I have lived on this planet. This is to not say that I want to stop reading the discussions here altogether. I only discuss what I can & not what I cannot.

• Everything I discuss & post here is based on my current understanding of science, technology etc which my K-12 curriculum has given me + reading a lot of online articles as well helps to learn a little out of the box too.
• I can do basic calculations such as multiplication, division, addition, subtraction to help me ascertain certain things such as how what would be the MTOW of a plane with so and so payload but that is about it, I cannot go into deep understanding of the equations posted here by some of the members, I can at the most write them down, enter the values and get the solution, that is Input => Output. Other than that, I have no interest in advanced mathematics.
• I have already given an introduction of myself in this thread. Post in thread 'New Members' Introduction' https://defenceforumbharat.com/threads/new-members-introduction.4/post-1105

Have a great day ahead. Hope to learn a lot from guys like you. Sayanora.

Click to expand...

I am sure 2 people who don't like advanced maths can discuss well

Before going to sleep I will explain why increasing bypass ratio increases more thrust.

Momentum = M X V
Kinetic energy = (1/2) x M X V X V= .5MV^2
Force or thrust is directly proportional to rate of change of Momentum (newtons second law)

So to increases thrust either increases velocity or mass flow rate.

But assume we increases velocity by 2 to increase thrust by 2.

M X 2V = 2MV

But the Kinetic energy becomes .5 × m ×(2v)^2 = 4(.5MV^2)

The energy requirement becomes 4 times.

But if we increases mass flow rate by 2 to increase thrust by 2.

2M X V =2MV

But the Kinetic energy becomes .5 X(2 M) X V X V =2(.5MV^2)

So it is evident that we can get more thrust by sacrifice operating velocity but this has a limit.

We cant reduce velocity too much otherwise after a certain point lift become very less.

From the above it is evidently clear that increasing bypass ratio increase thrust but also reduce operational velocity.


Another thing to consider is increasing bypass ratio reduce the velocity of output jet. The theoretical maximum speed a plane can travel is same as the velocity of output put jet otherwise the relative velocity of jet with respect to air becomes negative. So increasing bypass ratio also reduce the maximum velocity of aircraft thus reducing performance at high supersonic speeds.

scholar of war said:

Before going to sleep I will explain why increasing bypass ratio increases more thrust.

Momentum = M X V
Kinetic energy = (1/2) x M X V X V= .5MV^2
Force or thrust is directly proportional to rate of change of Momentum (newtons second law)

So to increases thrust either increases velocity or mass flow rate.

But assume we increases velocity by 2 to increase thrust by 2.

M X 2V = 2MV

But the Kinetic energy becomes .5 × m ×(2v)^2 = 4(.5MV^2)

The energy requirement becomes 4 times.

But if we increases mass flow rate by 2 to increase thrust by 2.

2M X V =2MV

But the Kinetic energy becomes .5 X(2 M) X V X V =2(.5MV^2)

So it is evident that we can get more thrust by sacrifice operating velocity but this has a limit.

We cant reduce velocity too much otherwise after a certain point lift become very less.

From the above it is evidently clear that increasing bypass ratio increase thrust but also reduce operational velocity.

Click to expand...

Isn't there a factor of increasing drag with a larger bypass. Is there a mathematical representation for that ?

karn said:

Isn't there a factor of increasing drag with a larger bypass is there a mathematical representation of that ?

Click to expand...

I don't think this is that easy to get a formula.

Since there can be infinite variation in design of plane,engine etc.

If it exist it must be some very complex empirical relationship which i don't know.

In my personal experience since i have used cfd to calculate drag and lift on aerofoils.
Industry use cfd to calculate drag on complex bodies.

You can look little bit about computational fluid dynamics to get more idea

At this time with basic knowledge i would guess AMCA's Supercruise with F414

Bhartiya Sainik said:

Agenda - supercruise
Can AMCA SUPERCRUISE with F414?

Click to expand...

Perhaps Yes, between Mach 1.2 to 1.4

Bhartiya Sainik said:

SHOULD AMCA supercruise withF414?

Click to expand...

Yes

> On one side we have Mother Nature's unbeatable laws of PCM putting limits of performance - higher drag, higher KE required, higher complexity design.
> On the other side we have global engineers pushing for Speed (both cruising & maximum) -
Turboprop -> Turbojet/fan -> Ramjet -> Turbo-Ramjet -> Variable cycle adaptive engine
> KE required increases as square of velocity, looks like panick, but comes from Calorific value of researched fuels with secret sauce & ingredients - small volume but big kick., especially after compression.
> Currently SuCr is attached to Turbo-jet/fan, considered an "overkill", inefficient, gimmick, etc by many as per Performance studies on engine types. Some would say it is war-time mode/feature.
But if nations're already prepared to do it in war-time since 3 decades & will continue in future also then what can civillians do?

(https://commons.wikimedia.org/wiki/File:Specific-impulse-kk-20090105.png)
(https://commons.wikimedia.org/wiki/File:Gas_turbine_efficiency.png)

That means if military is persistent on SuCr then we civillians are stuck with something somewhere, perhaps with engine efficiency & drag graphs are bothering us too much, while there are structural factors also.

We should keep in mind that objective, priorities of military & civil jets are different.
MoD & Aur force also have budget & SOP for peace time Ops incl. pre-planned routes, responses,flight altitude, speed kkeping in mind min. fuel expenses, maintenance & spares charges, etc.
But design focuses on war time performance also.

Let's again look at the collage of drag, the highlighted part of graph in green color.
Real world is not ideal but full of resistance, losses, still as wing sweep angle increases, the drag decreases drastically.
Coefficient of drag Cd & Fd Force of drag are different, just like (Cf=u) coefficient of ground friction & (F=u.M.g) ground friction force.

So just like ground force equation (F - Mg = Ma), we need Flight equation of motion. As per the scope of forums, we common people enthusiasts don't need complex 3-axis equation including roll, pitch, yaw, like Navier-Stokes equation, etc. But this kind of forum has to go on for 1-2 decades at least.
Let's take a basic example of level flight. Make corrections/alterations where you like.



Drag are of many types



But for our low IQ minds, we need a simplified formula for overall drag - The Drag equation



Fd increases as square of Velocity, but
the Cd of swept wing jet is 0.02 +/-
Air density at cruise altitudes is < 1 Kg/M^3. At 30Kft it is 0.458, at 50kft it is 0.186

NOTE - Make corrections/alterations as required.
Drag Force Equation Fd = (1/2) (Air density X Cd X Cross Section Area X Velocity^2)
Air density @ 40,000 feet = 0.3 Kg/m^3
Coefficient of drag Cd for wing sweel angle around 50 degrees = 0.02
Speed let's consider Mach 1.2 (411.6 m/s, round down to 410 m/s) which is considered bad for SuCr
Cross Section Area of AMCA at wingtip level, let's say = 8 m^2


Fd = (0.3 X 0.02 X 8 X 410 X 410)/2 = 4,034.4 N = 4.034 KN
If 2 F414 engines together produce 2x58 KN = 116 KN dry thrust
then net thrust = T - Fd = 112 KN, it is like an engine with 56 KN dry thrust
It is analogous to 116 people are pulling something forward & 4 people are trying pull behind.
Net result is 112 pulling forward. This is simple theoretical level-flight example. I am curious to know actual values.

Bhartiya Sainik said:

GE F-414 engine's SFC with inlet dia. 79cm at 100% power (57.8-61.83 KN) is 20.5-23.25 g/KN/s depending upon model. 75 KN JV engine is planned.
2 engines, so AMCA SFC will be 41-46.5 g/KN/s at 100% power.
So 2.37-2.87Kg/s fuel will be used.
AMCA empty weight 12 T + 50% fuel 3.25 T + 4 Astr MK3 SFDR 0.88 T = 16.13 tons
T/W ratio at 100% power = 2x58/9.8 /16.13 = 0.73
Fuel per ton = (2,370-2,870)/16.13 = 146.93-177.92 gm/s/T.
let's assume that with 0.73 T/W AMCA can also supercruise at M 1.2 (411.6 m/s).
50% fuel 3.25 tons while on supercuise will be depleted in 1,132-1,371 seconds or 18-23 minutes covering 466-564 Kms.
When new engine with 75 KN dry thrust will be available then hopefully 6 AAMs will be carried.
T/W ratio at 100% power = 2x75/9.8 / (16.13 + 0.44) = 0.92
Then hopefully AMCA will supercruise around M 1.5

Click to expand...

Those who want deeper dive can include laws like conservation of momentum/energy/mass; equations of Navier-Stokes, Bernouli, Laplace, Euler, etc; Reynold's number, Critical Mach number, Stagnation pressure, etc, etc.

Practically the avionics computer of modern jet fighter is equivalent of compacted average Super-computer calculating many 3D equations every millisecond.
Computing power is measured in units like MIPS - Millions Instructions/Second & FLOPS - Floating Point Operations/Second).

View: https://x.com/Varun55484761/status/1814499908160049446?t=JUf13uG6DXo3Pbt_-C3-yw&s=19