AMCA - Advanced Medium Combat Aircraft (HAL)

[Lonewolf]

Please show through diagram or photo, thanks.

Not at my home , out somewhere , will post soon .

 

[Lonewolf]

Please show through diagram or photo, thanks.

So basically it transmits mechanical power in form of angular motion from aircraft gearbox which is driven by a electric motor , and transfer it to engine gearbox where the power is further transmitted to Central axle to provide torque .

See the above image , the accessories gearbox visible gets the initial torque from this shaft .

This system can be eliminated if u introduce it axially inside the engine as electric motor are smaller nowadays but for that engine should be a clean sheet design .

Similar for electricity generation , in air these axles alongwith constant speed drive unit can help in electricity generation , can be removed and inserted in the axis of engine ,like in the RR next gen turbofan design

 

[Bhartiya Sainik]

So basically it transmits mechanical power in form of angular motion from aircraft gearbox which is driven by a electric motor , and transfer it to engine gearbox where the power is further transmitted to Central axle to provide torque .

View attachment 133128

See the above image , the accessories gearbox visible gets the initial torque from this shaft .

This system can be eliminated if u introduce it axially inside the engine as electric motor are smaller nowadays but for that engine should be a clean sheet design .

Similar for electricity generation , in air these axles alongwith constant speed drive unit can help in electricity generation , can be removed and inserted in the axis of engine ,like in the RR next gen turbofan design

The PTO shaft is not present in the diagram u shared. The 2 vertical shafts are radial shafts.
That electric motor called starter in current engines need APU or GPU for power.

Why i was confused was bcoz in civil engines there is no PTO shaft. There are radial & longitudinal shafts connected to engine gearbox, part of engine set. So why would DRDO highlight it if part of GE-414 engine.

So civil engine start is by APU bleed air usually.
- APU bleed air turns air-starter which is like a small windmill
- air-starter through gearbox turns longitudinal shaft (not PTO shaft)
- longitudinal haft through bevel gears turn radial shaft
- radial shaft through bevel gear turn high pressure compressor & shaft N2
- air flow created by N2 rotates low pressure compressor & shaft N1

Beyond 20% rpm the fuel is injected & sprk plugs ignite it.

After searching before my 1st reply itself i found that the PTO shaft is in military jets & actually b/w AMAD (Airframe Mounted Accesory Drive) & EMAD (Engine Mounted Accesory Drive), or simply airframe gearbox & engine gearbox.
And the APU/JFS turns the shafts (PTO then radial) through the gearbox rather than by its bleed air.

But from above 2-D diagram it appears that the PTO shaft is directly connected to fan shaft which would obstruct air duct which is not true.
The PTO shaft is actually below the engine in most cases or in western engines.

GE-414 also follows the same arrangement as above

The following is sketch of F-15 engine & gearbox where P-12 below engine are PTO shafts.

The following is example from MiG-29 where the PTO shaft is on top of engine & towards spine rather than forward:

So ultimately the PTO shaft is not part of engine set from manufacturer but just another part in the airframe.

Now coming to the Rolls Royce plans for Tempest 6th gen jet to install electromagnetic motor + generator directly with engine shaft -
- the motor/gen needs to be shielded well from intense heat.
- Because the engine could be throttled up/down randomly & rapidly, now the generator EM field will also rapidly & randomly change, means for a uniform current/voltage control is required, the stator-rotor magnetic field control needs very fine electronic calibration. It is not simple like mixer/juicer motor.
- the motor needs initial electricity from GPU or APU.
- the gearbox operates other rotating things also like pumps for fuel, engine-oil, hydraulic fluid, etc. All these have to be made electronic.

Let's see how US engine makers will respond.

 

[Blank]

 

[Super Flanker]

The term "International Engine House" refers to a Jet engine Company here right? That means we are indeed collaborating with a jet Engine company. But I am still in doubt, is it:
1)Rolls Royce?
2)Safran?
3)Any other.

 

[Aditya Ballal]

Wonder if HVT is hinting at something or is bored and wants to F around with us.

 

[shuvo@y2k10]

Different AMCA design that what was showcased in Aero-India 2021.

 

[SARTHAK]

Wonder if HVT is hinting at something or is bored and wants to F around with us.

no chance after s400 :-(

 

[Blank]

 

[Blank]

 

[Indx TechStyle]

Twitter is full of Mentally colonized people who always think that Bharat can't do anything on its own, if it does then it will always be piece of shit, and hence we should always import or do some stupid JVs and throw billions of dollars to a foreign company.

Location: Nazi India
Self proclaimed expert with nil knowledge. Nuff said.

 

[Indx TechStyle]

LOLOL

Who needs to go to PDF for idiotic musings?

 

[mokoman]

looks like engine fan blade ? AMCA engine ?

 

[MonaLazy]

Every day something new to learn, today's: even an inactive radar can be detected!

- F117 is the first plane since the early 1950s without on board radar since even an inactive system can be detected by an enemy's probing radar therefore the F117 would be built around a laser guided weapon system designed to deliver LGBs.
- It carries no defensive weapons relying totally on stealth and mission planning!
-Stealth really does not mean you are invisible so you have to account for that & your tactics is where you do that. The F117s tiny RCS dramatically reduces the effective range of radar installations creating gaps in the AD web that it can slip thru undetected
- Tho the 43 F117s assigned to desert storm accounted for only 2.5% of the coalition's air forces, they destroyed over 40% of all strategic targets during the war! Flew nearly 1300 missions without a single scratch
- Northrop founder Jack Northrop had worked on designs for an all wing aircraft- during WW2 he built the XB-35 (4 engine flying wing bomber)- after the war Northrop replaced the props with 8 turbo jets (YB-49) flight testing revealed stability problems that could not be corrected before the advent of FBW tech. USAF cancelled the program in 1949 ordering that the last 11 hulls be broken and sold for scrap- disillusioned Jack Northrop resigned from the company and left the aircraft industry entirely! Later B-2 from the same company had the same span to the inch as the YB-49! No tail, no rudders YB-49 uses split surfaces of the wing tips to bank etc same with B-2
- Northrop's experience with the tacit blue proved that a stealthy vehicle could be constructed of smooth curved surfaces that would flow the radar energy along the exterior skin producing small but manageable radar spikes that could be diverted away from the source
- The most difficult part of the B-2 was not desiging the shape but building it. About 900 different materials were tried before settling on carbon fibre composites (stronger than steel, lighter than aluminium, extremely durable, yet can be moulded to create precisely controlled contours)!
- B-2, unlike F117, requires radar to identify threats and targets in all weather and from high altitudes- preventing radar emissions from revealing the position of B-2 to enemy was a challenge. Solved by very tightly controlling the emissions- limiting what we put out from the aircraft in terms of where it went, how it went there, how often it went there so no one could trace the emissions back to the aircraft and get its location
- Stealth is still in its infancy- there will not be an airplane made in the future that doesn't look at stealth tech, have to for its survivability.
- Future potential of stealth could be most fully and dramatically realized in UCAVs- can carry twice the payload of a manned fighter, at 1/3rd the cost since it would not require pilot activated controls or a life support system. The UCAVs performance would also not be limited by the limits of human physiology. No loss of life.

 

[SwordOfDarkness]

Every day something new to learn, today's: even an inactive radar can be detected!

- F117 is the first plane since the early 1950s without on board radar since even an inactive system can be detected by an enemy's probing radar therefore the F117 would be built around a laser guided weapon system designed to deliver LGBs.
- It carries no defensive weapons relying totally on stealth and mission planning!
-Stealth really does not mean you are invisible so you have to account for that & your tactics is where you do that. The F117s tiny RCS dramatically reduces the effective range of radar installations creating gaps in the AD web that it can slip thru undetected
- Tho the 43 F117s assigned to desert storm accounted for only 2.5% of the coalition's air forces, they destroyed over 40% of all strategic targets during the war! Flew nearly 1300 missions without a single scratch
- Northrop founder Jack Northrop had worked on designs for an all wing aircraft- during WW2 he built the XB-35 (4 engine flying wing bomber)- after the war Northrop replaced the props with 8 turbo jets (YB-49) flight testing revealed stability problems that could not be corrected before the advent of FBW tech. USAF cancelled the program in 1949 ordering that the last 11 hulls be broken and sold for scrap- disillusioned Jack Northrop resigned from the company and left the aircraft industry entirely! Later B-2 from the same company had the same span to the inch as the YB-49! No tail, no rudders YB-49 uses split surfaces of the wing tips to bank etc same with B-2
- Northrop's experience with the tacit blue proved that a stealthy vehicle could be constructed of smooth curved surfaces that would flow the radar energy along the exterior skin producing small but manageable radar spikes that could be diverted away from the source
- The most difficult part of the B-2 was not desiging the shape but building it. About 900 different materials were tried before settling on carbon fibre composites (stronger than steel, lighter than aluminium, extremely durable, yet can be moulded to create precisely controlled contours)!
- B-2, unlike F117, requires radar to identify threats and targets in all weather and from high altitudes- preventing radar emissions from revealing the position of B-2 to enemy was a challenge. Solved by very tightly controlling the emissions- limiting what we put out from the aircraft in terms of where it went, how it went there, how often it went there so no one could trace the emissions back to the aircraft and get its location
- Stealth is still in its infancy- there will not be an airplane made in the future that doesn't look at stealth tech, have to for its survivability.
- Future potential of stealth could be most fully and dramatically realized in UCAVs- can carry twice the payload of a manned fighter, at 1/3rd the cost since it would not require pilot activated controls or a life support system. The UCAVs performance would also not be limited by the limits of human physiology. No loss of life.

Ghatak UAV is essentially exactly this, a flying wing. Great stealth, and since afterburner on a stealth airplane is anyway undesirable, Kaveri fits it well too.

 

[MonaLazy]

Ghatak UAV is essentially exactly this, a flying wing. Great stealth, and since afterburner on a stealth airplane is anyway undesirable, Kaveri fits it well too.

Flying wing, FTW! I wanted to draw attention to the radars on a stealth plane- here we keep talking about nose-mounted, chin-mounted side facing and rearward radars. Each of those can reveal your position and defeat your own stealth shaping!

How the mission is planned, to fly in between AD nets, how the target is illuminated etc are very important details after the stealth plane is ready and in the hands of the IAF. I did not know until now that even a switched-off radar can be detected!

Stealth is truly complex to master, deploy & exploit.

Well seems like IR signature studies are being done on AMCA.

IR stealth is a whole different ball game. I was rambling only about RF stealth.

 

[fire starter]

Well seems like IR signature studies are being done on AMCA.

 

[SavageKing456]

Well seems like IR signature studies are being done on AMCA.

The paper was published on September last year

 

[scatterStorm]

Aerodynamics issue. China's J31 earlier tried a trapezoidal rudder but later ditched it for a slanted one.

View attachment 131027

View attachment 131028

I think this has definitely have to do with radar returns and using the body of aircraft to generate more lift to compensate for smaller rudders. If you see SU57, you would also see smaller rudders.

 

[Harry101]

Location: Nazi India
Self proclaimed expert with nil knowledge. Nuff said.
View attachment 134737

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