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JF-17 Block-3 -- Updates, News & Discussion

All things being equal higher bypass should lead lower SFC. But the that will come at a cost (relatively) to throttling performance along high altitude and high speed performance.

I see your point, but the relationship of TFSC with aircraft performance is really about the speed with little or no effect on altitude and thrust (in terms of aircraft performance)

Altitude: Over high altitudes, SFC drops anyway due to improved fuel consumption due to differences between the internal engine temperature and outside air.

Thrust: No co-relation of TFSC with thrust since some studies suggest there is less than 1% effect on the TFSC with an increase of thrust.

Speed: TFSC increases with an increase in mach number as per available linear models such as below. However, the increase in the overall thrust of the engine will more or less maintain the high speed characteristics of WS-13 compared to let's say, an RD-93


Screen Shot 2020-03-27 at 10.53.31 PM.png


One interesting development happening in US and per some literature in China too is development of variable bypass ratio engine to get the best of both types but it’s a decade or two away.

And some thought the age of innovation in traditional jet engine saga is over.
 
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Why any reason??? for Block-1/2???
Dont take my word for it but,

Overhaul facility -(If PAF had to change into the WS-13 type than why Dedicate commitment to a temporary cause)
Reliable jet engine with good performance
No as such problems or Issues with the Jet engine
PAC fixed the Smoke Issue-- (If they wanted WS-13 than they would have not fixed the smoke)

Rd93 is here to stay Making adjustments to an engine, establishing technical depots and training personnel comes with a heavy price tag. Also the Pilots would have to re train their brain and revise training.

In pashto we say "LAAS LANDI" which translates to "under the hand" and that is what the Rd-93 means for PAF.

jf-17 and the rd93 is the CD-70 Of PAF.

With current thrust configuration the service Life is beautiful, PAC can increase the thrust but it will come at the cost of higher serviceability and lower Life cycle.
 
Dont take my word for it but,

Overhaul facility -(If PAF had to change into the WS-13 type than why Dedicate commitment to a temporary cause)
Reliable jet engine with good performance
No as such problems or Issues with the Jet engine
PAC fixed the Smoke Issue-- (If they wanted WS-13 than they would have not fixed the smoke)

Rd93 is here to stay Making adjustments to an engine, establishing technical depots and training personnel comes with a heavy price tag. Also the Pilots would have to re train their brain and revise training.

In pashto we say "LAAS LANDI" which translates to "under the hand" and that is what the Rd-93 means for PAF.

jf-17 and the rd93 is the CD-70 Of PAF.

With current thrust configuration the service Life is beautiful, PAC can increase the thrust but it will come at the cost of higher serviceability and lower Life cycle.
Block-3 need a better thrust engine to compensate power consumption of AESA (KJ-7A) and extra weight of additional avionics and fuel, and huitong blogpost already hinted that WS-13 will be ready for production for Block-3
 
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If ws-13e is indeed more of a power house over rd-93 as rumored than it indeed might come in with the block 3.

Block-3 need a better thrust engine to compensate power consumption of AESA (KJ-7A) and extra weight of additional avionics and fuel, and huitong blogpost already hinted that WS-13 will be ready for production for Block-3
That is if it gives significantly more power than rd-93
 
Block-3 need a better thrust engine to compensate power consumption of AESA (KJ-7A) and extra weight of additional avionics and fuel, and huitong blogpost already hinted that WS-13 will be ready for production for Block-3
some one will answer that for you who has more experience than me. If not I have some Idea not a lot for fighter.
 
how so? well, I read somewhere on the old PDF forum that Pakistan had already purchased like, 500 or 600 RD93s from russia far in advance during the Musharraf days so that they'll never have a problem with engine availability but Allah hu alim.
The figure of 500 was often reported in the early days. Not sue if those were actual purchases or contracts with options. It was said at the time that this number would be enough for a production run of 250 aircraft. i.e. one spare engine for each aircraft.
 
I see your point, but the relationship of TFSC with aircraft performance is really about the speed with little or no effect on altitude and thrust (in terms of aircraft performance)

Altitude: Over high altitudes, SFC drops anyway due to improved fuel consumption due to differences between the internal engine temperature and outside air.

Thrust: No co-relation of TFSC with thrust since some studies suggest there is less than 1% effect on the TFSC with an increase of thrust.

Speed: TFSC increases with an increase in mach number as per available linear models such as below. However, the increase in the overall thrust of the engine will more or less maintain the high speed characteristics of WS-13 compared to let's say, an RD-93


View attachment 618037



And some thought the age of innovation in traditional jet engine saga is over.

What I meant was not about SFC. But the impact of altitude and speed on the engine performance. That is, an engine with high bypass ratio will not output optimum thrust at higher altitude and at higher speed compared to a lower bypass ratio engine. Also the throttling will be laggy comparatively.

But as you pointed the difference is not much and as such the impact might be smaller.
 
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