JF-17 Thunder Multirole Fighter [Thread 6]

[Mughal-Prince]

Romanian !

Hehehehe Female tau sonhri lugdi ae main kiya ji

 

[genmirajborgza786]

It wouldn't matter. Thrust is not the only issue, DSI much like on the F-35 won't allow it to achieve mach 2.

yes, I heard something like that about the DSI , but bro, if the DSI is somehow adjusted to the RCS to be compatible with the Rd-93(MA) at full capacity (Mach2) then I believe that the jf-17 thunder can truly be the wonder bird of the third world in its price range , now that the RD-93(MA) is available, so if the speed adjustment can be done with DSI in block II ,I don't thing we'll need to worry about the block III anymore. jf-17 block II @ mach 2 with the RD-93 MA & the J-31 can do the rest, all that is needed is a twin engine medium weight platform in between these two to give that over all, solid force back up & the PAF is all set

 

[slapshot]

Hehehehe Female tau sonhri lugdi ae main kiya ji

Sharam kar phelay he teri hadian nikal ai hin

 

[Jungibaaz]

yes, I heard something like that about the DSI , but bro, if the DSI is somehow adjusted to the RCS to be compatible with the Rd-93(MA) at full capacity (Mach2) then I believe that the jf-17 thunder can truly be the wonder bird of the third world in its price range , now that the RD-93(MA) is available, so if the speed adjustment can be done with DSI in block II ,I don't thing we'll need to worry about the block III anymore. jf-17 block II @ mach 2 with the RD-93 MA & the J-31 can do the rest, all that is needed is a twin engine medium weight platform in between these two to give that over all, solid force back up & the PAF is all set

The issue is not with the quoted max thrust of the engine, I agree that more thrust is good, improving the TWR is good for the JF-17. The problem of DSI is not that engine doesn't provide enough thrust or that it weighs too much, the flow of air at those speeds is the problem. Complex, heavy moving parts were often used in the past for intakes to do their job properly at speeds, at and above mach 2, variable geometry.

DSI did away with those, DSI has no moving parts, adds to efficiency at other lower speeds, it requires less complexity in the intake design, therefore it saves weight, maintenance cost, if LOS from a normal intake leaves the engine blades exposed it also reduces one of the forward scatter regions, reducing RCS, it also lessens the need to have RAM application. So don't get me wrong, I can clearly see why this intake design was chosen.

But, the trade off is that it loses efficiency at high speed, it can vary from depending on the geometry of the specific DSI design in question. However, the air flow through the intake that feeds the engine at speeds approaching mach 2 is such that the engine no longer yields it's max thrust. The design is technically a '2 shock', and it rapidly starts to lose efficiency compared to older 3 and 4 shock designs. Pressure recovery is substantially lower. This is why aircraft with this design be it JF-17 or F-35 don't have mach 2 quoted as their max speed. The same should be true for the J-10B.

Now I'm not saying that under the right conditions the JF-17 can't fly at speeds at and approaching mach 2, it could, but it carries risk and unwanted effects, you can do it, but not without effecting the engine.

 

[flamer84]

@flamer84 - You came to Pakistan and didn't meet me ?

Meh,just some of our parasites freeriding around the world without any purpose and on state money...It's not like they're doing something for our national defence.

You should have dumped them on taliban controled territory.

 

[genmirajborgza786]

The issue is not with the quoted max thrust of the engine, I agree that more thrust is good, improving the TWR is good for the JF-17. The problem of DSI is not that engine doesn't provide enough thrust or that it weighs too much, the flow of air at those speeds is the problem. Complex, heavy moving parts were often used in the past for intakes to do their job properly at speeds, at and above mach 2, variable geometry.

DSI did away with those, DSI has no moving parts, adds to efficiency at other lower speeds, it requires less complexity in the intake design, therefore it saves weight, maintenance cost, if LOS from a normal intake leaves the engine blades exposed it also reduces one of the forward scatter regions, reducing RCS, it also lessens the need to have RAM application. So don't get me wrong, I can clearly see why this intake design was chosen.

But, the trade off is that it loses efficiency at high speed, it can vary from depending on the geometry of the specific DSI design in question. However, the air flow through the intake that feeds the engine at speeds approaching mach 2 is such that the engine no longer yields it's max thrust. The design is technically a '2 shock', and it rapidly starts to lose efficiency compared to older 3 and 4 shock designs. Pressure recovery is substantially lower. This is why aircraft with this design be it JF-17 or F-35 don't have mach 2 quoted as their max speed. The same should be true for the J-10B.

Now I'm not saying that under the right conditions the JF-17 can't fly at speeds at and approaching mach 2, it could, but it carries risk and unwanted effects, you can do it, but not without effecting the engine.

Dil tod diya Boss Apne....

at-least we have an fighter jet of our own, I just hope that a good medium weight platform can be inducted

 

[Armstrong]

Meh,just some of our parasites freeriding around the world without any purpose and on state money...It's not like they're doing something for our national defence.

You should have dumped them on taliban controled territory.

You no want our birdie ?

 

[flamer84]

You no want our birdie ?

We don't want no birdies.Romania doesn't need any birdies even though Russia is waging war on our borders.Romania said it wanted birdies and other goodies and said that this year defence budget would be much highrer but Surprise !-Today figures for the 2015 Defence Budget came out and no much promised throughout last year "0.3% of GDP increase for Defence" was in sight...not a single penny,nothing,nada,rien,niente !---hence my joyfull mood right now...

 

[Armstrong]

We don't want no birdies.Romania doesn't need any birdies even though Russia is waging war on our borders.Romania said it wanted birdies and other goodies and said that this year defence budget would be much highrer but Surprise !-Today figures for the 2015 Defence Budget came out and no much promised throughout last year "0.3% of GDP increase for Defence" was in sight...not a single penny,nothing,nada,rien,niente !---hence my joyfull mood right now...

You don't have any Conflicts going on; right ?

 

[Mughal-Prince]

Sharam kar phelay he teri hadian nikal ai hin

Hehehe Kiya kerain control nahin hota

 

[flamer84]

You don't have any Conflicts going on; right ?

Just across our border Russia is dismantling out neighbour,Grad rocket by Grad rocket.

The same story as in WW2,then we sent soldiers with WW1 artillery and Molotovs against T34's and acted shocked when 2 of our Armies were anihilated at Stalingrad.

Romanian Armies in the Battle of Stalingrad - Wikipedia, the free encyclopedia

 

[razgriz19]

28 November 2014

A 05 member delegation from Romania led by Mr. Sorin Encutescu, State Advisor to the Prime Minister of Romania visited PAC on 05 December, 2014

05 December, 2014

Romania operates Mig-21 and F-16s (future)
Maybe they're looking for a replacement for Migs. PAF can help with BOTH!

 

[flamer84]

Romania operates Mig-21 and F-16s (future)
Maybe they're looking for a replacement for Migs. PAF can help with BOTH!

No.

There's a board of Defence experts and enthusiasts in Romania,who for years have come up with countless solutions to strenghten our Army and are always knocking on doors.One day ,a member of the "Defence Commity of Parliament"(tired of them insisting) jokingly told them,straight in their face:"I know your want a modern Army but the Army will fight you couragesly not to be modernised and better equipped".

 

[Jungibaaz]

Dil tod diya Boss Apne....

at-least we have an fighter jet of our own, I just hope that a good medium weight platform can be inducted

Buddy, there's nothing wrong with DSI, being limited to mach 2 most of the time, for safety and what not is nothing to be disappointed about. This aircraft is perfect.

You were right about pretty much everything else.

 

[SQ8]

Now I'm not saying that under the right conditions the JF-17 can't fly at speeds at and approaching mach 2, it could, but it carries risk and unwanted effects, you can do it, but not without effecting the engine.

Sigh.. they wont believe it unless it is backed up by something much more solid(although some still wont and for them we can only say YOLO)
JSF Diverterless Supersonic Inlet | Code One Magazine

Inlet designs for fighter aircraft must also account for a layer of low-energy air that forms on the surface of the fuselage at subsonic and supersonic speeds. (These layers also form on the inlet compression surfaces.) This layer of slow moving, turbulent air, called a boundary layer, can create chaos when disturbed by the shock waves created by the inlet. The result can be unwanted airflow distortions at the engine face. If the shock wave/boundary layer interaction is severe enough, the engine will stall. The boundary layer thickens with increased speed and increased forebody distance, the length from the nose of the airplane to the inlet itself.

Designers of supersonic aircraft deal with this boundary layer phenomenon by redirecting the layer before it reaches the engine and placing the inlet away from the boundary layer in the freestream, where airflow is unaffected by the boundary layer phenomenon. On the F-16, a structure called a diverter provides a 3.3-inch gap between the fuselage and the upper lip of the inlet. The size of the gap equates to the thickness of the boundary layer at the maximum speed of the F-16. Other fighters remove boundary layer airflow with combinations of splitter plates and bleed systems. The latter redirect the unwanted airflow through small holes in the compression ramps to bleed ducts within the inlet. The DSI bump functions as a compression surface and creates a pressure distribution that prevents the majority of the boundary layer air from entering the inlet at speeds up to Mach 2. In essence, the DSI does away with complex and heavy mechanical systems.

The flight tests covered the entire F-16 flight envelope and achieved a maximum speed of Mach 2.0.
The new inlet showed slightly better subsonic specific excess power than a production inlet.