DRDO and PSU's

[randombully]

I had seen a documentary of northrop where they said they achieved stealth with not just edge alignment but also with CURVED SURFACES such that radar waves doesn't bounce back instead scatter away. I think the documentary was abt tacit blue technology demonstrater which was equivalent to have blue which was further developed into f117.
The tacit blue achieved stealth with curved surface unlike f117. The learnings were basis for b2 spirit and later yf23. The chin of yf23. They had also said indirectly yf23 was more stealthier than yf22.

Edge alignment doesn't make a aircraft stealth.
It's just one of the components of stealth, a component used to reduce radar return.

A fighter jet without no edge alignment but designed to scatter radar waves away, in whatever direction except sender direction
with no funneling into certain directions can be be stealthy enough to be called a stealth jet but with edge alignment it could become more stealthy.
a design with single continous wing with an constant angle designed to scatter radar waves away become even more stealthy as it scatters them away and form narrow lobes on side of the aircraft, basically flying wing designs.
Flying wings without vertical tails and constant wing maintaining constant angle, basically have perfect edge alignment.

Stealth by shape:-
include shaping to scatter radar waves away from the sender's direction, edge alignment where possible to further improve stealth, trying to reduce round surfaces at junctions, trying to reduce 90° angles as much as you can.
Best shapes are flying wing, but also most aerodynamically challenging to fly and maneuver.
So a balance is needed between stealth and aerodynamics, based on the requirements.

Stealth by material:-
RAM, RAS.
Good ram is one that can reduces rcs by 15-20 dbsm, can handle high speed, can handle high heat, is long lasting.
Now all these "high" and "long lasting" is relative.
As "good" is also relative.
RAS are basically composites material with RAM like ability to significantly absorb radar waves.
Are much Superior, Stealth is baked into skin of stealth jet, much more capable of handling high speed, heat, longer lasting.
Less hassle to regularly paint the ram.
lockheed calls it's RAS as fibremat, used in f35.
F35 has both ras skin and further coating of ram.


Now how stealthy a jet is depends on combined effect of all these.

And f117's design of having so many angles and edges instead of round surface was due to limit of computers at that time to design a stealth jet.
Better computer+software=can now design a stealth jets with round surfaces too.

 

[fire starter]

View: https://x.com/Indrani1_Roy/status/1899294721840971939?t=R97Db3XpJVCcxaNIsS2vVQ&s=19

 

[SwordOfDarkness]

Edge alignment doesn't make a aircraft stealth.
It's just one of the components of stealth, a component used to reduce radar return.

A fighter jet without no edge alignment but designed to scatter radar waves away, in whatever direction except sender direction
with no funneling into certain directions can be be stealthy enough to be called a stealth jet but with edge alignment it could become more stealthy.
a design with single continous wing with an constant angle designed to scatter radar waves away become even more stealthy as it scatters them away and form narrow lobes on side of the aircraft, basically flying wing designs.
Flying wings without vertical tails and constant wing maintaining constant angle, basically have perfect edge alignment.

Stealth by shape:-
include shaping to scatter radar waves away from the sender's direction, edge alignment where possible to further improve stealth, trying to reduce round surfaces at junctions, trying to reduce 90° angles as much as you can.
Best shapes are flying wing, but also most aerodynamically challenging to fly and maneuver.
So a balance is needed between stealth and aerodynamics, based on the requirements.

Stealth by material:-
RAM, RAS.
Good ram is one that can reduces rcs by 15-20 dbsm, can handle high speed, can handle high heat, is long lasting.
Now all these "high" and "long lasting" is relative.
As "good" is also relative.
RAS are basically composites material with RAM like ability to significantly absorb radar waves.
Are much Superior, Stealth is baked into skin of stealth jet, much more capable of handling high speed, heat, longer lasting.
Less hassle to regularly paint the ram.
lockheed calls it's RAS as fibremat, used in f35.
F35 has both ras skin and further coating of ram.


Now how stealthy a jet is depends on combined effect of all these.

And f117's design of having so many angles and edges instead of round surface was due to limit of computers at that time to design a stealth jet.
Better computer+software=can now design a stealth jets with round surfaces too.

An illustration for your point -

Without assuming RAM, these are some simulations of radar return

Without very good stealth alignment -



Su57, jumbled mess that gives decent return at a variety of angles, meaning it can be tracked by radar as long as radar is strong enough.


With very good alignment -



F35, strong returns are collected at very narrow range of angles (+- 1 degree!!), meaning any change in attitude and you lose lock. Practically impossible to track.


Interested peeps can go through this

F-35 vs J-20 vs Su-57 Summary

Introduction Previously, we have done HFSS simulation to evaluate the mean and median radar cross section as well as the radar scattering pattern of the four common stealth fighters namely F-35A, S…

basicsaboutaerodynamicsandavionics.wordpress.com

Good stuff, includes J20 as well. Website also does Rafale simulation and comparison with J20, for those who do a vague comparison of the two as justification for MRFA/import.

 

[randombully]

An illustration for your point -

Without assuming RAM, these are some simulations of radar return

Without very good stealth alignment -

View attachment 27280

Su57, jumbled mess that gives decent return at a variety of angles, meaning it can be tracked by radar as long as radar is strong enough.


With very good alignment -

View attachment 27279

F35, strong returns are collected at very narrow range of angles (+- 1 degree!!), meaning any change in attitude and you lose lock. Practically impossible to track.


Interested peeps can go through this

F-35 vs J-20 vs Su-57 Summary

Introduction Previously, we have done HFSS simulation to evaluate the mean and median radar cross section as well as the radar scattering pattern of the four common stealth fighters namely F-35A, S…

basicsaboutaerodynamicsandavionics.wordpress.com

Good stuff, includes J20 as well. Website also does Rafale simulation and comparison with J20, for those who do a vague comparison of the two as justification for MRFA/import.

Already went through those Sims.
But good graph( though x band graph would be better), it further helps to visualise the edge alignment.
And also further help to ubderstand edge alignment is not just about wings and tails.
As mentioned before other surfaces with different angles and planes can also be designed to scatter radar waves in somewhat similar direction(somewhat edge aligned).
Su57's designs except horizontal edges is not much optimised for edge alignment.
In jets like f35, j20, other surfaces like nose area, intakes, curves, vertical slanted tails, fuselage etc are also some what edge alignment.
While su57's scattering causes more percentage of shattered waves to interact with each other, and due to this—interference can occur (constructively or destructively) among the scattered waves. Under certain conditions, a small fraction of that scattered energy is redirected back toward the radar source.
this is what we see in the graph of su57

In short, non–edge‐aligned surfaces can cause some percentage of scattered radar energy to “return” via interference.
Edge alignment minimizes it.
Now in non stealth designs, it's not that big of a deal, because of increase in rcs at most will be 0.001-0.008m2(assuming composite surface with ram/ras)due to interference of waves.
But in stealth designs this becomes significant big deal.

 

[Corvus Splendens]

View: https://x.com/Ray70409890/status/1899356459663843781

 

[Ultraman]

View: https://x.com/Indrani1_Roy/status/1899294721840971939?t=R97Db3XpJVCcxaNIsS2vVQ&s=19
View attachment 27277

was the CDR done for TEDBF , i thought money was released only after CDR

 

[Corvus Splendens]

was the CDR done for TEDBF , i thought money was released only after CDR

CDR is pending and may take 2 years.

 

[randombully]

An illustration for your point -

Without assuming RAM, these are some simulations of radar return

Without very good stealth alignment -

View attachment 27280

Su57, jumbled mess that gives decent return at a variety of angles, meaning it can be tracked by radar as long as radar is strong enough.


With very good alignment -

View attachment 27279

F35, strong returns are collected at very narrow range of angles (+- 1 degree!!), meaning any change in attitude and you lose lock. Practically impossible to track.


Interested peeps can go through this

F-35 vs J-20 vs Su-57 Summary

Introduction Previously, we have done HFSS simulation to evaluate the mean and median radar cross section as well as the radar scattering pattern of the four common stealth fighters namely F-35A, S…

basicsaboutaerodynamicsandavionics.wordpress.com

Good stuff, includes J20 as well. Website also does Rafale simulation and comparison with J20, for those who do a vague comparison of the two as justification for MRFA/import.

Another thing I would also remind is that.
The graph is designed for stealth fighters, hence highly sensitive.
So if you just focus on the graph without looking at the sensitivity, su57's rcs looks too much worse.

This graph Is much more upto scale.
In both x and s band.
And you can also see the effect of su57's irst on its stealth when it's turned on.



This Graph better represent the "slight" increase in rcs of su57(irst turned off), because of its less focused edge alignment, it's ducts( even though they have radar blockers), it's relatively less stealth optimised canopy, its irst even when it's turned off( the irst from behind is highly coated in ram/ras).

You can also see the "median" value of su57 is 3× the value of 35( 0.06 of su57 vs 0.02 of f35).

And irst on, the median frontal rcs of su57 jump further 0.11m2 to reach 0.17m2.

(All of this is without ram/ras applied).

Now if we apply good ras/ram we can further decrease of rcs of 15-20dbsm.


So su57 is still miles stealthier than let's say rafale.

 

[Ultraman]

An illustration for your point -

Without assuming RAM, these are some simulations of radar return

Without very good stealth alignment -

View attachment 27280

Su57, jumbled mess that gives decent return at a variety of angles, meaning it can be tracked by radar as long as radar is strong enough.


With very good alignment -

View attachment 27279

F35, strong returns are collected at very narrow range of angles (+- 1 degree!!), meaning any change in attitude and you lose lock. Practically impossible to track.


Interested peeps can go through this

F-35 vs J-20 vs Su-57 Summary

Introduction Previously, we have done HFSS simulation to evaluate the mean and median radar cross section as well as the radar scattering pattern of the four common stealth fighters namely F-35A, S…

basicsaboutaerodynamicsandavionics.wordpress.com

Good stuff, includes J20 as well. Website also does Rafale simulation and comparison with J20, for those who do a vague comparison of the two as justification for MRFA/import.

great article .

for J-20

for rafale-C ,

50x more ? , J-20 seems to be impressive.

Rafale-C radar scattering simulation

Introduction Rafale is a French twin-engine, canard delta wing, multirole fighter aircraft designed and built by Dassault Aviation. Rafale was developed as the 4.5 generation fighter intended to re…

basicsaboutaerodynamicsandavionics.wordpress.com

 

[Bleh]

Edge alignment doesn't make a aircraft stealth.
It's just one of the components of stealth, a component used to reduce radar return.

A fighter jet without no edge alignment but designed to scatter radar waves away, in whatever direction except sender direction
with no funneling into certain directions can be be stealthy enough to be called a stealth jet but with edge alignment it could become more stealthy.
a design with single continous wing with an constant angle designed to scatter radar waves away become even more stealthy as it scatters them away and form narrow lobes on side of the aircraft, basically flying wing designs.
Flying wings without vertical tails and constant wing maintaining constant angle, basically have perfect edge alignment.

Stealth by shape:-
include shaping to scatter radar waves away from the sender's direction, edge alignment where possible to further improve stealth, trying to reduce round surfaces at junctions, trying to reduce 90° angles as much as you can.
Best shapes are flying wing, but also most aerodynamically challenging to fly and maneuver.
So a balance is needed between stealth and aerodynamics, based on the requirements.

Stealth by material:-
RAM, RAS.
Good ram is one that can reduces rcs by 15-20 dbsm, can handle high speed, can handle high heat, is long lasting.
Now all these "high" and "long lasting" is relative.
As "good" is also relative.
RAS are basically composites material with RAM like ability to significantly absorb radar waves.
Are much Superior, Stealth is baked into skin of stealth jet, much more capable of handling high speed, heat, longer lasting.
Less hassle to regularly paint the ram.
lockheed calls it's RAS as fibremat, used in f35.
F35 has both ras skin and further coating of ram.


Now how stealthy a jet is depends on combined effect of all these.

And f117's design of having so many angles and edges instead of round surface was due to limit of computers at that time to design a stealth jet.
Better computer+software=can now design a stealth jets with round surfaces too.

Okay so I learnt two new things in the meantime.

1st is, having verticals planes exponential increase RCS & so edge-alignment is necessary for aircraft with vertical stabilizer. Tailless ones can concentrate on aerodynamics more.

2nd is, the size of individual wing-edge exponentially increase RCS & so aircraft with horizontal stabilizers need edge alignment to reduce that, or they'll have to have very small wings. Flying wings don't need to. Their central bulge (to fit shit in) ensures much of the rear-edge is hidden from frontal radars.

PS: F-117 tails are designed to be nearly hidden from the front.

 

[Aaj Ka Hero]

View: https://www.youtube.com/live/wE91uVdZhjM?si=6FYmMjV1vf5Plskn
From 50:00 to 57:00, General is talking how CCS not releasing money and bureaucracy is destroying growth.

 

[AbRaj]

Placeholder is playing good cop to the ACM IAF's bad cop. Game on .


View: https://youtu.be/pmP6-iurgSY?si=NjSBowKb3lyAcvY1

Indian defence ministry is in the hands of the God(Bhagwan bharose). Turdnath Singh is a dummy.

 

[ArjunMK1A]

View attachment 27255

Again the rocket force is coming in a grand fashion.

1. Pinaka - 45 to 120KM
2. Smerch - 120-170
3. Pralay - 150-500KM
4. BM-04 - 400-1500KM
5. - 500-800KM
6. Nirbhay and his sons - 1500-2000+

Pending -- ATACAMS equivalent. Hopefully Solar Industries may show the 250KM rocket.

Need ISR Drones.

Those were also available.
1. Rustom
2. Tapas.

 

[Cyclops]

View: https://www.youtube.com/live/wE91uVdZhjM?si=6FYmMjV1vf5Plskn
From 50:00 to 57:00, General is talking how CCS not releasing money and bureaucracy is destroying growth.

Completely agree with the MOD and bureaucracy being at fault but I don't know about the stuff he said at the end there... it sounded a lot like he wanted more screwdrivergiri.

Why "negative list hatao"?

And he gave the same rhetoric that obnoxious military-brats on X often regurgitate, i.e. "go sell it to foreign nations if the Indian military is not buying your things" (wrt ATAGS).

The demand and therefore the sustenance of your domestic defence production is sustained by domestic purchase mostly; foreign sales don't often count for the majority of the purchases of defence equipment across the world. Why then should desi defence manufacturers depend on foreign militaries who themselves are subject to the whims of foreign politicians?

Bad arguments.

We literally heard not a few days back how IA generals demeaned Baba Kalyani and he was forced to humble them. So no, I'm not sure I want to give them the benefit of the doubt just yet.

 

[randombully]

great article .

for J-20

for rafale-C ,

50x more ? , J-20 seems to be impressive.

Rafale-C radar scattering simulation

Introduction Rafale is a French twin-engine, canard delta wing, multirole fighter aircraft designed and built by Dassault Aviation. Rafale was developed as the 4.5 generation fighter intended to re…

basicsaboutaerodynamicsandavionics.wordpress.com

Rafale, does not have stealthy shape at all.
What it has is composites and some ram treatment, which reduces it's rcs by at most 10dbsm.( more heavier ram treatment will not make sense, as it will require lot more mantinence and rafale still has to carry external weapons, so wastage of time and money), tejas mk2 from front will rival rafale in low rcs.

Just based on shape j20 should be miles stealtheir than rafale.
Anyone with Basic knowledge on how radar scattering works should be able to identify it.
And you don't need to do scattering simulation with detailed model or do testing in anechoic chamber to know that.


also fighter jets use x bands, arrays.
S bands are generally used by awacs.
And L bands are generally ground based( the small L band array in su57 is not a radar, it's used for FF and EW).

 

[randombully]

Okay so I learnt two new things in the meantime.

1st is, having verticals planes exponential increase RCS & so edge-alignment is necessary for aircraft with vertical stabilizer. Tailless ones can concentrate on aerodynamics more.

2nd is, the size of individual wing-edge exponentially increase RCS & so aircraft with horizontal stabilizers need edge alignment to reduce that, or they'll have to have very small wings. Flying wings don't need to. Their central bulge (to fit shit in) ensures much of the rear-edge is hidden from frontal radars.

PS: F-117 tails are designed to be nearly hidden from the front.

1st, not from front.
And it's technically exponential from side, but not that much in real life.
Like for example take rcs of 1m2 and 0.1m2
The decrease in detection range for 90% reduction in rcs is only 40%-50%
Now take 1m2 to 0.01m2 the detection range decrease for 99% reduction in rcs is 60-70%.



And the benefits of lower rcs continues to decrease.








Basically once you reach f35 level stealth, then it's not much useful to go even more stealthy. Especially when IRST exists.
Only make sense if going for more stealthy design doesn't harm aerodynamics, manurablility and other things much.
Like flying wing ucav, they are not expected to have even decent manurablility.
Or if your gonna make a larger plane which doesn't need decent manurablility( large size= more rcs) like a stealth bomber b2, b21 etc.

That's the reason these loyal wing man drones like our own warrior has twin v tails, due to its size it's already gonna be in the realm or even lower than f35 in rcs, so going much lower while sacrificing manurablility is not Worth the trade, and loyal wingman drones/concepts from around the world have v tails.

2, the increase in size of anything exponentially increase rcs( big size=big rcs, if other factors are constant)
They can still designs the wings and horizontal tails in a way to scatter the radar wave away from the original direction and not be edge aligned, but they need edge alignment to make sure the scattered waves from wing and horizontal tail scatter in same direction so they doesn't intersect with each other and causes interference which can cause some amount of intersecting waves to reflect in other directions and one of those directions can be the original direction where radar wave came from.

Yeah, the back edges of all aircraft are more or less hidden from radar.

 

[vampyrbladez]

View: https://x.com/HovhanNaz/status/1899355911338008688/photo/1

 

[Indianhawk]

Again the rocket force is coming in a grand fashion.

1. Pinaka - 45 to 120KM
2. Smerch - 120-170
3. Pralay - 150-500KM
4. BM-04 - 400-1500KM
5. - 500-800KM
6. Nirbhay and his sons - 1500-2000+

Pending -- ATACAMS equivalent. Hopefully Solar Industries may show the 250KM rocket.

Need ISR Drones.

Those were also available.
1. Rustom
2. Tapas.

Need something cheaper than pralay to pound everything at 200km distance.

 

[Indianhawk]

View: https://x.com/Indrani1_Roy/status/1899294721840971939?t=R97Db3XpJVCcxaNIsS2vVQ&s=19
View attachment 27277

Tebdf is now delayed so much that it is not longer guaranteed what final form will it take.
If further delayed navy will demand 30 more rafales by 2035.
I guess that was the plan all along .

 

[jaijaganath]

View: https://x.com/ReviewVayu/status/1899358915772535057


Everything
Every single fucking thing will die infront of us