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J-10 might not needed as they don't add anything to PAF's capability

Hi,




Buddy,

You are not well informed----the world engine----cost CHRYSLER CORP a billion dollars---the 4 cylinder in the Dodge Darts and alfa Romeo and other vehicles---and that was over 5 years ago when it went into full production---so that cost was around 10 years ago when it started.

Buddy, what u wrote about engine? in above lines u said it long process!! I may agree on u but it may take 5 years ,its time to start work on it, when Pak star to work on JF 17, they must initiate engine too. the lazy civilian Indian organization has already build the engine , while PAF is much efficient and they have 1000s of mechanical , metallurgical, designee and software engineers

The whole idea behind a jet engine is that you accelerate the fluid going through it with as driving force a pressure gradient. The pressure in a jet engine is the highest right after the last stage of compression (for axial compressors). The combustion then takes place with minimum pressure loss and the the expansion begins through the turbines and finally through the nozzle . The high pressure created by the compressor forces the fluid to go out through the back. In other words, it creates the favorable pressure gradient used to accelerate the flow and produce thrust. By drawing out a Brayton cycle you can also show the effect this has on the efficiency.


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Kaveri Engine by GTRE

India’s Home-Grown Supersonic Fighter Jet

Kaveri

Kaveri Engine is a technologically complex and vital system for the LCA as well as its future variants. It incorporates state-of-the-art technologies and provides the required thrust for indigenous competence in this critical area.

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ZAPOROZHYE MACHINE-BUILDING DESIGN BUREAU PROGRESS STATE ENTERPRISE NAMED AFTER ACADEMICIAN A.G.IVCHENKO



Lets put in that way , if we could find? What is the difference between a jet engine and a rocket engine? and 2nd question is
Why do Jet Engines Have a Compressor?

Can you explain how various jet engines work, including the turbojet, turbofan, turboprop, and turboshaft? In particular, what is the difference between a turbojet and a turbofan and which is more efficient?


Reference physicsforums . kom / threads/why-do-jet-engines-have-a-compressor. 265277/

there is page called aerospaceweb
 
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Jet Engine Types , PAC if spend 3 million dollar on salaries than people working at PAC can develop any of the type given below!! let them urge to sit and do it!!

Thermodynamic cycles can be divided into two general categories: power cycles, which produce a net power output, and refrigeration and heat pump cycles, which consume a net power input. The thermodynamic power cycles can be categorized as gas cycles and vapor cycles. In gas cycles, the working fluid remains in the gas phase throughout the entire cycle. In vapor cycles, the working fluid exits as a vapor during one part of the cycle and as a liquid during another part of the cycle. Internal combustion engines and gas turbines undergo gas power cycle.

The two major application areas of gas-turbine engines are aircraft propulsion and electric power generation. This section introduces the ideal cycle for gas-turbine engine - Brayton cycle and jet-propulsion cycle for aircraft propulsion.

brayton-cycle.png

The Ideal Brayton Cycle


  • lets explain how various jet engines work, including the turbojet, turbofan, turboprop, and turboshaft? In particular, what is the difference between a turbojet and a turbofan and which is more efficient?

turbojet1.jpg

Diagram of an axial-flow turbojet

The turbojet (and the turbofan) can also be fitted with an afterburner. An afterburner is simply a long tube placed in between the turbine and the nozzle in which additional fuel is added and burned to provide a significant boost in thrust. However, afterburners greatly increase fuel consumption, so aircraft can only use them for brief periods.



turbojet.jpg

Comparison of a turbojet and a turbojet with an afterburner
A further variation on the turbojet is the turbofan. Although most components remain the same, the turbofan introduces a fan section in front of the compressors. The fan, another rotating series of blades, is also driven by the turbine, but its primary purpose is to force a large volume of air through outer ducts that go around the engine core. Although this "bypassed" air flow travels at much lower speeds, the large mass of air that is accelerated by the fan produces a significant thrust (in addition to that created by the turbojet core) without burning any additional fuel. Thus, the turbofan is much more fuel efficient than the turbojet. In addition, the low-speed air helps to cushion the noise of the jet core making the engine much quieter.



turbofan.jpg

Comparison of a low-bypass turbofan with long ducts and a high-bypass turbofan with short ducts
Turbofans are typically broken into one of two categories--low-bypass ratio and high-bypass ratio--as illustrated above. The bypass ratio refers to the ratio of incoming air that passes through the fan ducts compared to the incoming air passing through the jet core. In a low-bypass turbofan, only a small amount of air passes through the fan ducts and the fan is of very small diameter. The fan in a high-bypass turbofan is much larger to force a large volume of air through the ducts. The low-bypass turbofan is more compact, but the high-bypass turbofan can produce much greater thrust, is more fuel efficient, and is much quieter.

A concept similar to the turbofan is the turboprop. However, instead of the turbine driving a ducted fan, it drives a completely external propeller. Turboprops are commonly used oncommuter aircraft and long-range planes that require great endurance like the P-3 Orion and Tu-95.



turboprop.jpg

Schematic of a turboprop engine
The turboprop is attractive in these applications because of its high fuel efficiency, even greater than the turbofan. However, the noise and vibration produced by the propeller is a significant drawback, and the turboprop is limited to subsonic flight only. In a typical turboprop, the jet core produces about 15% of the thrust while the propeller generates the remaining 85%.

Another noteworthy variation on the turbojet is the ramjet. The idea behind this type of engine is to remove all the rotary components of the engine (i.e. fans, compressors, and turbines) and allow the motion of the engine itself to compress incoming air for combustion.



ramjet.jpg

Simple schematic of a ramjet
However, the price of this simplicity is that the ramjet can only produce thrust when it is already in motion. Instead of using a compressor to draw in air and compress it for combustion, the ramjet relies on the motion of the aircraft to ram air into the engine at high enough speed that it is already sufficiently compressed for combustion to occur. Since ramjets typically cannot function until reaching about 300 mph (485 km/h) at sea level, they have been rarely used on manned aircraft. However, the ramjet is more fuel efficient than turbojets or turbofans starting at about Mach 3 making them very attractive for use on missiles. Such missiles are typically launched using rocket motors that accelerate the vehicle to high-subsonic or low-supersonic speeds where the ramjet is engaged.

Finally, let us talk briefly about the turboshaft, a version of the jet engine that powers nearly every helicopter built today. As the below image illustrates, the turboshaft utilizes many of the same components as a turbojet.



turboshaft.jpg

Schematic of a turboshaft engine
Air is drawn in through an inlet, compressed by low- and high-pressure compressor blades, mixed with fuel and burned in a combustion chamber, passed through turbine blades, and exhausted through a nozzle. The key difference between the turboshaft and previously discussed engines is that the turbine not only drives the compressors, but the shaft is also connected to a gear box that drives a helicopter's rotor blades. Although the engine shaft rotates about the horizontal, the gear box contains a sequence of gears that transform that motion to a rotation about the vertical axis as required by a helicopter main rotor. Helicopters also typically operate at much lower altitudes than aircraft where dust, sand, and other debris can easily be sucked into the engine. To address this problem, most turboshaft engines are equipped with a particle separator that filters out and expels the unwanted dust before the air flow reaches the compressor.



separator.jpg

Schematic of a turboshaft engine particle separator
While the turboprop is still popular on aircraft where low fuel consumption is vital, nearly all aircraft today employ some version of the turbofan, usually high-bypass turbofans. The high thrust, low fuel consumption, and low noise levels of these engines make them well-suited to both military and commercial applications. Today, about the only use for turbojets and ramjets is in missiles. Air-breathing, long-range, subsonic missiles like the Tomahawk use turbojets since these are small, relatively low-cost systems that provide much greater range than is possible with a rocket of comparable size. Ramjets find applications on air-breathing, long-range, supersonic missiles for similar reasons. Turboshafts, of course, have displaced the piston engine as the primary powerplant used on helicopters. To continue learning more about aircraft propulsion, be sure to check out NASA's Learning Guide on Propulsion for a wealth of information, animations, and interactive applets about rockets, propellers, ramjets, and gas turbine engines.


 
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We simply don't know. Chinese military is very secretive about its cutting edge capabilities. The Europeans are generally straight forward, whereas the Americans will boast like a car salesman. So, there can be little truth found about such matters on the internet.
There is no way, we are a small weak countries rise slowly, carefully confidential, is our means of survival.
 
In the reply of rafales J-20 is the best possible aircraft but I have heard that it is a non-export version...
Plz its my humble request to put that mirage 2000 out of list because we are talking about that Pakistan don't aquire j10 aircraft then how it will procure mirages.....
I think PAF should order J-20 aircrafts as the came into mass production and invest in the J-31 program as it will be good in future and will be easy to procure about 100-150 of 5th gen fighter....
 
In the reply of rafales J-20 is the best possible aircraft but I have heard that it is a non-export version...
Plz its my humble request to put that mirage 2000 out of list because we are talking about that Pakistan don't aquire j10 aircraft then how it will procure mirages.....
I think PAF should order J-20 aircrafts as the came into mass production and invest in the J-31 program as it will be good in future and will be easy to procure about 100-150 of 5th gen fighter....
China has no ability to simultaneously J-10 (A, B, C). J-11 (A, B). J-15, J-16 (unconfirmed). J-20. J-31. FBC-1. Y-20 aircraft such as mass production.... China has reached its limits.
 
Buddy, what u wrote about engine? in above lines u said it long process!! I may agree on u but it may take 5 years ,its time to start work on it, when Pak star to work on JF 17, they must initiate engine too. the lazy civilian Indian organization has already build the engine , while PAF is much efficient and they have 1000s of mechanical , metallurgical, designee and software engineers

A little correction here, it’s erroneous to assume Kaveri (or GTX-35 VS) is the absolute first turbojet/turbofan to be designed/developed from the ground up (from scratch) by GTRE – it’s not. In fact Kaveri is not at all a “from the scratch” development in the first place – it more of an upgrade.

It’s predecessors were GTX-37 U (turbojet) -> GTX-37 UB (it’s turbofan version) -> GTX-35 (enhanced turbojet based on 37U tech). And Kaveri (or GTX-35 VS) is more of an upgrade of GTX-35 (same core etc.). The following schematic depicts the Kaveri lineage:

Kaveri_History_zps97e9fc11.png


Note: How the reduction of HPC stages were carried out to reduce weight, while increasing the turbine efficiency by increasing TET (and OPR) simultaneously – all of these required adavcnes in materials tech as well. Also note, the mass-flow drop during graduating from a turbojet to turbofan necessitating further efficiencies in turbine and compressor technologies (or increase in the number of corresponding stages).
Pls note the 37 series is from 70s and early 80s while the 35 series from late 80s to early-mid 90s.


But all of these, still doesn’t make the above “lack-of-experience” argument completely void – as none of these predecessors actually flew and are more of a laboratory products (or tech demos).
Back in 1983, right after the LCA project was sanctioned, a concurrent engine evaluation study was conducted by GTRE - in 2 years time, in 1985, this was completed and the summary finding was "No contemporary engine is available world-wide that meets the LCA engine specifications".

Anyway, similarly a “Materials Committee” of GTRE in 1989, after a comprehensive study of various materials of contemporary turbo-jet/fan engines, and also after taking into account the infrastructure facilities available within the country in general and production capability of MIDHANI and DMRL, recommended the development of material, batch production and type certification process etc.

The Kaveri development programme was then launched in 1989.

First is the technological and the industrial capability. Indian premier aircraft building agency HAL have produced thousands of engine in house. There are big Giants as far as the material know how is concerned including pvt companies like TATA and L&T for metallurgy.

Second is the economics. Somehow let us assume Pakistan launched a turbofan engine development, but before that it has to set up numbers of institution for the certification , testing, research and development of the building blocks of the turbofan engine, actuator, materials etc. Lets assume Pakistan is able to produce a decent engine in 5 years somehow with the help of China, and the developed engine is par with the RD93 engine specification, but in the due course the technological advancement have forced PAF to put more LRU's on JF-17, and then the required thurst now demands more. That will put the risk of wasting the money offcourse on the industrial investment, not on the knowledge, R&D know how. Second is the scale of the economics -- to lower the engine cost, Pakistan have to produce the engine in qty, if it is competeting with the Rusian RD-93 engine, which is been produced in large qty for the global customer. So in short, to make a place in the competetive world, you have to actually replaced some one, not by requesting, but by beating the shit of the rival product, because why would PAF would prefer the pakistani engine, being new one, and cost more, when it could easily get the product from the Russia.
 
Jet Engine Types , PAC if spend 3 million dollar on salaries than people working at PAC can develop any of the type given below!! let them urge to sit and do it!!

Thermodynamic cycles can be divided into two general categories: power cycles, which produce a net power output, and refrigeration and heat pump cycles, which consume a net power input. The thermodynamic power cycles can be categorized as gas cycles and vapor cycles. In gas cycles, the working fluid remains in the gas phase throughout the entire cycle. In vapor cycles, the working fluid exits as a vapor during one part of the cycle and as a liquid during another part of the cycle. Internal combustion engines and gas turbines undergo gas power cycle.

The two major application areas of gas-turbine engines are aircraft propulsion and electric power generation. This section introduces the ideal cycle for gas-turbine engine - Brayton cycle and jet-propulsion cycle for aircraft propulsion.

brayton-cycle.png

The Ideal Brayton Cycle


  • lets explain how various jet engines work, including the turbojet, turbofan, turboprop, and turboshaft? In particular, what is the difference between a turbojet and a turbofan and which is more efficient?

turbojet1.jpg

Diagram of an axial-flow turbojet

The turbojet (and the turbofan) can also be fitted with an afterburner. An afterburner is simply a long tube placed in between the turbine and the nozzle in which additional fuel is added and burned to provide a significant boost in thrust. However, afterburners greatly increase fuel consumption, so aircraft can only use them for brief periods.



turbojet.jpg

Comparison of a turbojet and a turbojet with an afterburner
A further variation on the turbojet is the turbofan. Although most components remain the same, the turbofan introduces a fan section in front of the compressors. The fan, another rotating series of blades, is also driven by the turbine, but its primary purpose is to force a large volume of air through outer ducts that go around the engine core. Although this "bypassed" air flow travels at much lower speeds, the large mass of air that is accelerated by the fan produces a significant thrust (in addition to that created by the turbojet core) without burning any additional fuel. Thus, the turbofan is much more fuel efficient than the turbojet. In addition, the low-speed air helps to cushion the noise of the jet core making the engine much quieter.



turbofan.jpg

Comparison of a low-bypass turbofan with long ducts and a high-bypass turbofan with short ducts
Turbofans are typically broken into one of two categories--low-bypass ratio and high-bypass ratio--as illustrated above. The bypass ratio refers to the ratio of incoming air that passes through the fan ducts compared to the incoming air passing through the jet core. In a low-bypass turbofan, only a small amount of air passes through the fan ducts and the fan is of very small diameter. The fan in a high-bypass turbofan is much larger to force a large volume of air through the ducts. The low-bypass turbofan is more compact, but the high-bypass turbofan can produce much greater thrust, is more fuel efficient, and is much quieter.

A concept similar to the turbofan is the turboprop. However, instead of the turbine driving a ducted fan, it drives a completely external propeller. Turboprops are commonly used oncommuter aircraft and long-range planes that require great endurance like the P-3 Orion and Tu-95.



turboprop.jpg

Schematic of a turboprop engine
The turboprop is attractive in these applications because of its high fuel efficiency, even greater than the turbofan. However, the noise and vibration produced by the propeller is a significant drawback, and the turboprop is limited to subsonic flight only. In a typical turboprop, the jet core produces about 15% of the thrust while the propeller generates the remaining 85%.

Another noteworthy variation on the turbojet is the ramjet. The idea behind this type of engine is to remove all the rotary components of the engine (i.e. fans, compressors, and turbines) and allow the motion of the engine itself to compress incoming air for combustion.



ramjet.jpg

Simple schematic of a ramjet
However, the price of this simplicity is that the ramjet can only produce thrust when it is already in motion. Instead of using a compressor to draw in air and compress it for combustion, the ramjet relies on the motion of the aircraft to ram air into the engine at high enough speed that it is already sufficiently compressed for combustion to occur. Since ramjets typically cannot function until reaching about 300 mph (485 km/h) at sea level, they have been rarely used on manned aircraft. However, the ramjet is more fuel efficient than turbojets or turbofans starting at about Mach 3 making them very attractive for use on missiles. Such missiles are typically launched using rocket motors that accelerate the vehicle to high-subsonic or low-supersonic speeds where the ramjet is engaged.

Finally, let us talk briefly about the turboshaft, a version of the jet engine that powers nearly every helicopter built today. As the below image illustrates, the turboshaft utilizes many of the same components as a turbojet.



turboshaft.jpg

Schematic of a turboshaft engine
Air is drawn in through an inlet, compressed by low- and high-pressure compressor blades, mixed with fuel and burned in a combustion chamber, passed through turbine blades, and exhausted through a nozzle. The key difference between the turboshaft and previously discussed engines is that the turbine not only drives the compressors, but the shaft is also connected to a gear box that drives a helicopter's rotor blades. Although the engine shaft rotates about the horizontal, the gear box contains a sequence of gears that transform that motion to a rotation about the vertical axis as required by a helicopter main rotor. Helicopters also typically operate at much lower altitudes than aircraft where dust, sand, and other debris can easily be sucked into the engine. To address this problem, most turboshaft engines are equipped with a particle separator that filters out and expels the unwanted dust before the air flow reaches the compressor.



separator.jpg

Schematic of a turboshaft engine particle separator
While the turboprop is still popular on aircraft where low fuel consumption is vital, nearly all aircraft today employ some version of the turbofan, usually high-bypass turbofans. The high thrust, low fuel consumption, and low noise levels of these engines make them well-suited to both military and commercial applications. Today, about the only use for turbojets and ramjets is in missiles. Air-breathing, long-range, subsonic missiles like the Tomahawk use turbojets since these are small, relatively low-cost systems that provide much greater range than is possible with a rocket of comparable size. Ramjets find applications on air-breathing, long-range, supersonic missiles for similar reasons. Turboshafts, of course, have displaced the piston engine as the primary powerplant used on helicopters. To continue learning more about aircraft propulsion, be sure to check out NASA's Learning Guide on Propulsion for a wealth of information, animations, and interactive applets about rockets, propellers, ramjets, and gas turbine engines.




Hi,

If pakistan wants to---then it can invest in the WS10 / WS13 type of engines. They are already in production stage and available.

So---there is really no need to enter into the relay race from the start when you can readily join in at the advance stages.

The die has already been cast. Basically all the aircraft engine manufacturers are producing engines---and there will be no new engine producers---.
 
Are there any other alternative options boasting similar quality for the air force?
 
Are there any other alternative options boasting similar quality for the air force?

MIG-35 is the best solution. Strangely, no one is speaking for that. Had already pointed out various advantage. Here is again in short.

1. Excellent Dogfighter, short takeoff capability 4+ MRCA
2. Similarity of engine RD93/33
3. AESA available -- Zhuk RP-35 AESA with 1064 TR module, which will be the AESA radar of J-10 B, designated by Chinese with their own name.
4. Easily could be mated with the Chinese weapons.
5. Have IRST, HMDS, Digital cockpit,HOBS missile, IFR probe, Space of Internal ASPJ
6. Wide range of weaponary including cruise missile, Anti shipping, ARM and could fulfill Air superiority and multirole role.
7. Could take on IAF's Rafale, SU-30 MKI, and MIG-29K
8. If J-31 is inducted in future, will have same engine (Upgraded RD-33), which will lower down the maintainance cost.
9. Pakistan could have RD-33 Engine production, and MRO facility in Pakistan.

@Bilal Khan 777 @Quwa @MastanKhan @Dazzler
 
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MIG-35 is the best solution. Strangely, no one is speaking for that. Had already pointed out various advantage. Here is again in short.

1. Excellent Dogfighter, short takeoff capability 4+ MRCA
2. Similarity of engine RD93/33
3. AESA available -- Zhuk RP-35 AESA with 1064 TR module, which will be the AESA radar of J-10 B, designated by Chinese with their own name.
4. Easily could be mated with the Chinese weapons.
5. Have IRST, HMDS, Digital cockpit,HOBS missile, IFR probe, Space of Internal ASPJ
6. Wide range of weaponary including cruise missile, Anti shipping, ARM and could fulfill Air superiority and multirole role.
7. Could take on IAF's Rafale, SU-30 MKI, and MIG-29K
8. If J-31 is inducted in future, will have same engine (Upgraded RD-33), which will lower down the maintainance cost.
9. Pakistan could have RD-33 Engine production, and MRO facility in Pakistan.
Mig-35 is a good fighter but we are looking for a fighter which can provide us the capability of deeper penetration into enemy's territory while maintaining outstanding air superiority and the fighters which can provide us these capabilities and can be/are availbale to us are Eurofighter Typhoon and Su-35.
As for the engine of J-31 we can't be sure whether it would be Russian or Chinese.

Sorry for being off topic.
 
Mig-35 is a good fighter but we are looking for a fighter which can provide us the capability of deeper penetration into enemy's territory while maintaining outstanding air superiority and the fighters which can provide us these capabilities and can be/are availbale to us are Eurofighter Typhoon and Su-35.
As for the engine of J-31 we can't be sure whether it would be Russian or Chinese.

Sorry for being off topic.

For engine, J-31 most probably use RD-93 engine initially, till the maturity of the Chinese engine.
For EF-2000 most unlikely, due to the consollium of 5 nations.
For Su-35, the cost factor, and the cost of maintaining is very high plus, it cannot be inducted in numbers, whereas MIG-35 is relatively cheaper.
For deeper penetration, it would be suicidal, and would only lower the PAF capability, instead should fight the defensive fight, where, the ground Radar, Sams favour PAF.
And last but not the least MIG-35 is not shortlegged.
 
@Jhon Smith
It is not that simple to build a jet engine as you are saying. The main reason is the metallurgy which is very costly and time consuming. One has to develop different types of metals so that they are able to withstand the heat and other factors.

The Indian engine programe is very old but they are trying to say that it is new same as they claim about the Tejas.

Iran on the other hand has a well developed engine programe for their Saeqa aircraft because they had initially invested and collaborated with the US during the time of the Shah. Still we do not see any new engine from the Iranian.
 
Pakistan will have J 10c. That better have than J10.
 
J-10 adds many capabilities to PAF that F-16 can never add.

Just shouting out a few.

1. War time attrition losses replaced immediately.
2. Sanction free plane
3. Can be upgraded with avionics of PAF choice especially AESA
4. Numbers can be swelled up to 150 if required
5. Newer Chinese weapons can be integrated at will.
6. Cheaper to buy than F-16
7. Can replace Mirages instantly for A2G role taking the burden off F-16 shoulders for A2G role
8. Can be tested in combat in WOT ops inside Pakistan
9. Cheaper to operate than F-16 in WOT ops, using same or better A2G weapons as JF-17
10. Can save airframe life of F-16's by conducting more sorties in same role
11. Mystery plane for IAF as IAF have exercised with USAF F-16's already.
 
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