First Kamra Made JF17 to Fly on 23rd Nov...

[Abu Zolfiqar]

good news.....thanks

 

[Taha Samad]

do RD-33 have same issue with smoke?

yes i think rd-33 also has this problem.

B] Even a small trail of smoke is not good.[/B]

i don't thing smoke from the engine is a big problem.

firstly planes don't emit smoke at all throttle settings and speeds.
Secondly even engines that apparently are smoke free actually start emitting smoke at certain throttle settings.

black smoke just indicates that fuel is not being burned completely and signifies the fact that engine and intake design can further be improved to increase performance. if unburned carbon coming out with exhaust gases was such a big problem then mig-29 and tornado would have been regarded as a failed fighters.

and one interesting thing most engineers are familiar with is that when designing a system if you go on improving one performance parameter, most of the time you will deteriorate another one. e.g if you make a system more sensitive, you also make it more unstable. so a compromise has to be made between sensitivity and stability.

Similarly, making engine smoke free can be an easy task but in doing so engineers might end up deteriorating performance of engine. So a bit of smoke for better performance is a good bargain.

regards,
taha

 

[mjnaushad]

just "a bit"


????

do RD-33 have same issue with smoke? Even a small trail of smoke is not good. Is it during A/B or during dry thrust

Not good for plane or environment. ?? And if plane what are the bad effects? Sorry dont know much about Fighters.

 

[abbasniazi]

I found this post interesting, it also mentions the smoky part of RD93

Although the engine has come under a lot of scrutiny from Pakistani quarters, the main aspect has been over performance issues. The engine is considered to be smoky & under-powered, while reliability has also been expressed as a point of concern. With a presumed low TBO (Time Between Overhauls) the type has been stated as a weak-point.

The RD-93 is actually superior to all PAF service engines except the F100 series of the F-16 (however, it does have better response cycle to turbulence & dust), & is more fuel efficient, quieter, & reliable (as well having a longer lifespan) than the Atar 9C (Mirage III/5), WP-7 (F-7P) & WP-13 (F-7PG) in PAF service, all being turbojets & not comparable. The RD-93 itself actually would save the PAF on fuel & logistics, being economical to acquire & operate. It also offers much more thrust & efficiency than even the F100.

Its main weaknesses remain the smoky nature of the engine, & low-lifespan compared to the F100. Other weaknesses can be found in its design. Though not low on thrust (it is actually lighter than the Atar 9C & saved 400kg on South African Mirage F.1s during fits) the type is optimised for the twin-engined MiG-29. One possible solution is to produce the RD-33MK/MR (Naval) standard, with 19,400lb reheat coupled with weight savings on the FC-1

What appears to be unmentioned is that the RD-93 is much more powerful than the European RD199 (Tornado F3) & much more durable than the M53 (Mirage 2000) & is much better performing than both at high altitudes or turbulence. It also beats the F100 in such conditions. It's also designed for rapid repair & field maintenance & contrary to popular belief is not a thirsty engine. Though less durable than the F404 or PW1120 series (its US equivalents) it is actually more responsive to bird-strikes, & FOD.

The next phase of RD-93 development would focus on enlarging the blades of the fans (much the same way as the EJ200 or M88 & some re-designs around the engine. This should make it a revolution (as opposed to just an evolution) of the basic design, & may well go beyond 22k at reheat. Coupled with reduced FC-1 weight, this would equalise the F-16C/D with uprated PW F100-229E engines, (note: the F-16C/D is heavier & less agile) & the possibility of super-cruise.

My hope is that the Chinese can develop a suitable replacement but in all honesty as this rate they aren't doing too well. The WS-9 (Spey 202 copy) has the power but consumes more fuel & is too big & heavy, where the WP-14 is too under-powered & thirsty (being a turbojet) so improvements to the RD-93 is the only way to go.

 

[Abu Zolfiqar]

i find the RD-93 to be a bit under-powered and not the best match. For now it is more than sufficient.

I do hope for replacement soon. American engine would be too risky (politics) but perhaps we should work with the French.

Any engine options from the French?

 

[Abu Zolfiqar]

Not good for plane or environment. ?? And if plane what are the bad effects? Sorry dont know much about Fighters.

heat/IR signature i suppose?

and its easier to spot a fighter in the air when it leaves trails


I'm sure that for Jet fighters, JF-17 conforms to all international emmissions and Euro-III/Euro-IV standards



taha khan saab -- thanks for the info bro

 

[Taha Samad]

Not good for plane or environment. ?? And if plane what are the bad effects? Sorry dont know much about Fighters.

read post#76.i think it will hep.

i think LPG ricksha is more polluting than a plane emitting unburned carbon

its not damaging to a plane directly.
but it sure means that we are wasting some fuel in the sense that some carbon is being released without being burned.

secondly if plane emits too much smoke it can make you more visible to human eye

 

[Taha Samad]

heat/IR signature i suppose?

nope black smoke does not increase your IR signature. Because IR basically differentiates things on basis of temperture.Now smoke or no smoke exhaust gases coming out of engine are extremly hot anyway.So IR detector can detect them.

taha khan

 

[abbasniazi]

i find the RD-93 to be a bit under-powered and not the best match. For now it is more than sufficient.

I do hope for replacement soon. American engine would be too risky (politics) but perhaps we should work with the French.

Any engine options from the French?

I agree to you 100%, in my humble opinion, RD93 is underpowered.

The current RD93 in the current JF17 fighter aircraft gives it the Thrust to weight Ratio (TWR) of 0.95, however, the future RD93 with 10% extra thrust and JF17 with substantial Composite materials will improve this Ratio.

It is said if the Chinese proposed engine for JF17, which is WS13, becomes successfull, it will provide JF17 with 0.99 TWR, however, WS13 is not as efficient as the russian RD93.

 

[Abu Zolfiqar]

nope black smoke does not increase your IR signature. Because IR basically differentiates things on basis of temperture.Now smoke or no smoke exhaust gases coming out of engine are extremly hot anyway.

in retrospect, i was talking through my arse.

thanks for clarification

I was Pakhtunisizing your name!


I have my moments

 

[Abu Zolfiqar]

It is said if the Chinese proposed engine for JF17, which is WS13, becomes successfull, it will provide JF17 with 0.99 TWR, however, WS13 is not as efficient as the russian RD93.

and to me, this is the most cost-effective and smartest decision to make.

Once, of course, it is operational. This is the plan regardless. And I hope for our own sake that Pakistani interns, engineers, etc. are closely monitoring the WS-13 project; there is a lot to learn from the Chinese.

 

[abbasniazi]

Smoky RD93

 

[Wingman]

I agree to you 100%, in my humble opinion, RD93 is underpowered.

The current RD93 in the current JF17 fighter aircraft gives it the Thrust to weight Ratio (TWR) of 0.95, however, the future RD93 with 10% extra thrust and JF17 with substantial Composite materials will improve this Ratio.

It is said if the Chinese proposed engine for JF17, which is WS13, becomes successfull, it will provide JF17 with 0.99 TWR, however, WS13 is not as efficient as the russian RD93.

Well in my research JF17 pilots found it splendid. Somebody in the PDF sent a comparitive video of F16 and Thunder, performing a steep turn. Also want to quote F16 performed it on full ABs and thunder without it, means thunder was not in full military power mode, imagine if it would then..so RD93 is OK

 

[BlackenTheSky]

same day when NRO was declared

wat jf 17 have to do with NRO ....?

 

[PAFAce]

nope black smoke does not increase your IR signature. Because IR basically differentiates things on basis of temperture.Now smoke or no smoke exhaust gases coming out of engine are extremly hot anyway.So IR detector can detect them.

But it does mean that there is unburnt fuel, or rather, that the engine is not performing as efficiently as it should. In addition, leaving a trail of smoke not only provides an additional unwanted visible signature, but can also give the enemy a better idea of your trajectory.

In short, it shouldn't be there at all. New version RD-93s, supposedly, do not suffer from this issue. Let's wait for the pics on Nov 23rd, we'll know better.