Here some part of the interview with Academician Victor Mikhailovich Chepkin, Director General/Designer General of the Lyulka-Saturn joint-stock company (JSC) to Andrey Fomin (From Dec 98 Air Fleet)

What problems did you face while developing a swiveling nozzle?

– A lot of spears had been broken in choosing the very system of thrust vector deflection. The Americans went one way, we chose another, quite different to boot. While developing the swiveling nozzle, we encountered a most formidable problem – that of the seal between the moving and static parts of the nozzle. The exhaust gas pressure here reaches seven atmospheres with temperature running as high as 2000 degrees centigrade. The sealing of the point where two parts of the engine – the static and moving ones – meet, must be ideal, since the gas leakage here means a fire on board the aircraft. The second important problem is how to provide reliable control of the nozzle itself. Fancy that: during the take-off, the nozzle at an altitude of 15 m deflects on its own into the pitch position. In 1-1.5 seconds, the crash will be bound to happen. At a low speed, the pilot is absolutely unable to counter the sudden negative pitching moment, since the alteration of the thrust vector at full reheat is enormously powerful exceeding the effectiveness of the aircraft control surfaces.

Thus, developing the TVC version of the AL-31F engine, we had to solve most complicated technical problems and look for ways to ensure the highest degree of reliability of the system as a whole. Many a year of theoretic and experimental research resulted in successful resolution of those problems, and, for two years now, the AL-31FP-powered Su-37 fighter performs brilliantly at international airshows displaying magnificent maneuverability. Which is not the case with its foreign counterparts. There have not been any American or European combat aircraft featuring TVC engines at public airshows, though their development has been going on abroad for quite a while. Maybe, there is nothing to show yet…

The AL-31FP boasts an axial exit nozzle. That is to say the nozzle is circular. It is known that your overseas counterparts used to try to solve the thrust vector control problem via the use of a flat nozzle that should be easier to swivel. What do you think of that?

– In the late 1980s, we were engaged in the development of the flat nozzle too and conducted a thorough research. The Ufa-based Motor Scientific Production Enterprise under the guidance of Chief Designer Alexei A. Ryzhov manufactured an experimental flat nozzle that underwent a series of tests. The conclusions were as follows. Presently, the flat nozzle has two inherent snags which, in principle, have not been dealt with yet. Firstly, the turbine is round but the nozzle is flat with a distance between them being small. The distance cannot be increased because this would lead to an increase in the overall length of the aircraft, a loss of thrust, etc. While transforming the circular gas stream into the flat one, the nozzle, developed by Mr. Ryzhov, was losing 14-17% of thrust. Unfortunately, the gas stream cannot be “bent” as we would like it to. It has its own laws too. So far, no one has managed to transform the circular gas stream into the flat one without losing thrust. The very same snag was hit by the Americans in developing their F-117 featuring a non-afterburning engine. Such engines lose approximately 15% of thrust too. However, the F-117 is a specialised Stealth aircraft with the main requirement of ensuring “invisibility”. It does not need a real good thrust/weight ratio. That is why the Americans put up deliberately with an unavoidable loss of thrust but benefited from reduced signatures.

Secondly, the other primary problem is weight. The circular TVC nozzle produces only tensile stress while the flat one exerts bending stress as well. Those stresses require special measures to be taken to ensure the nozzle strength in order to avoid deformation of the nozzle. Those measures mean additional weight. The flat nozzle made of metal is heavier than the circular one by approximately half a tonne. Mind you, the whole AL-31FP fitted with its circular swivel nozzle weighs a little bit more than 1500 kg only. So, the use of a flat nozzle implies an extra tonne at the rear of a plane (two-engine are meant here, which make up the most of modern fighters). The problem can be circumvented through the use of the “carbon-carbon” materials which have low specific weight and can stand high temperature. But they burn in the end anyway, since they are based on the very same coal. Nobody has solved the problem of preventing carbon-carbon units from burning during their operation as part of an aircraft engine. Currently, such materials covered by a thick layer of fire-resistant ceramics are used only in manufacturing the control surfaces of rocket engines. The latter are actually disposable since their operation never exceeds 40-50 seconds while an aircraft engine service life amounts to 1,000 hours or more.

So, the problem of ensuring an effective long-term protection of the non-metal nozzle is still to be solved. Thus, development of the flat nozzle encounters two problems – the loss of thrust (and it is not resolved even in theory) and the extra weight. With those two problems in mind, we stick to the circular nozzle.

I want to know, whats been the experience of the Americans with their TVC engines. be it that on the experimental F-16 or the now operational F-22.

Have they solved the problems thats being said by DG of NPO Saturn ??? anyone got info?

C’mon JonS, u r wasting ur time on the established anti-Russian and a seasoned twister of this forum, which doesn’t make any sens :p ……….

Oh oh… and creadible Janes quote the figures of payload for the MiG-29M2 as 4,500Kg, i wonder, where that chap got that figures when he put his report… maybe another Jon Lake, who pieced his reports from all the online sources abt the deal on Gorshkov and still twisted the facts.

BTW, anyone got any more info on the said RD-333 which was brough up in an article in force magazine , which talked abt like 29,000 lbs of thrust???

Originally posted by Austin in Russia’s Modern Conventional & Nuclear Submarine Program

Russia Launches Project 677 submarine

JNI December-2004
By Richard Scott

Russia Launches Project 677 submarine
JNI December-2004
By Richard Scott

The first Project 677 ‘Lada’-class diesel-electric submarine has been formally launched from the Admiralty Shipyard in St Petersburg.

Named Sankt Peterburg in honour of the 300th anniversary of the founding of its namesake city, the submarine was launched into the River Neva on 28 October aboard a floating dock.Following test and acceptance activities , formal commisioning in to the Russian Federation Navy is expected in the second half of 2005 (now its commisioned)

Designed by the Rubin Central Design Bureau for Marien Engineering (CDBME) , the 1,765 tonne submerged displacement Project 677 ,( known as Amur in export derivative ) represent the fourth generation of Russian Conventional submarines. Laid down in december 1997, Sankt Peterburgs completion has been repeatedly delayed by funding shortages and more recently by equipment acceptance issues and revision of certain safety aspects. A second unit , an Amur 1650 export varaint, is awaiting funds for its completion at the Admiralty Shipyard.

Displacing 1,765 tonnes standard and 66.8m in length overall , the Project 677 design is somewhat smaller than the third-generation Project 636 ‘KILO’ -class design. Distinguished by Fin Mounted hydroplanes and cruciform control surfaces aft, it also differs from “Kilo” in its adoption of a single-hull design. Construction is from AB-2 steel ( for a max diving depth of 250 m)

According to data released by Rubin CDBME, Sankt Peterburg has a maximum submerged and surface speeds of 21 Kt and 10 kt respectively. [B]Submerged range at 3 kt will be 650 n miles with a maximum submerged endurance of 10 days.[/B] Cruising range under diesel power ( while snorkelling ) is put at 6000 n miles.

The Rubin CDBME said that refinements in “hullform, vibration supression and acoustic (hull) coating make the Project 677 three times quiter than Project 636″ . It added that much reduced self noise , combined with a new integrated sonar suite , will enable early detection of surface ships and untra-quite submarines at long ranges”.

Developed by Morphyspribor , the integrated sonar suite combines bow-mounted and towed arrays, plus separate intercept and mine avoidance arrays, under water telephones, noise-monitoring sensors and velocity and range measurement systems.

The Avrora Science and Production corporation has led the development of the Project 677 combat control system. The main control room accommodates all combat management and platform control functions, which interface with the common data transfer system. The Dual Workstation combat information control system and interfaces to weapon and countermeasures discharge management units on a seperate weapon control bus.

Another first for the Project 677 is the incorporation of a non-hull-penetrating optronic search mast , supplied by Elektropribor , in place of conventional search periscope. A conventional attack periscope is retained.

The submerged endurance mentioned there is w/o the AIP, which means that the battery power (and lower tonnage) have increased considerably which makes the sub to be submerged for a contineous for 10 days.

I want to know whats the submerged endurance for U-212/214 & Scorpene

This is very interesting. My guess is that they will go down in size, but the question is how much. Hopefully it will be CATOBAR, and not STOBAR, if they get a class of some size.

an EM cat is possible???…. 5 yrs of working time by the time the construction begin??…. also, I guess the catapult was reasdy for the N-powered carrier that was later dismantkled, so either they go with the steam cat, or develope the EM (with joint funding from India) or retain the STOBAR one ….

A new aircraft too? I wonder what that will be.

I hope its the new a/c that RAC-MiG has been said to be developing, that also makes sense, as I don seem it to be in the size of the Flankers or PAK-FA, so a smaller one with the LO design and internal bays wud be good one which can be carried in numbers.

Excuse me?

well, thats the term ‘we’ use for the Australians.

and frankly sean, its hard for me to argue against u, for i find u too good (& mannered) to be an American, so i usually skip confronting u … and it wont be any different in the future.

well well well…very interesting charts indeed.

I shall ready the invasion fleet sire.

U can’t be joking man …. or do u really think that IN is a blue water force, i hope the reality that some members pointed out in the Naval section is not enough for many Indians to come out of the dreams??? ….. btw, h many vessels of Indian Navy did u guys find in the recent Naval event which saw some Pakistani Vessels in the US??

Considering the fact that Barak was never ‘in’ for the LLQRM, what do mean by – ‘Barak will be out’ ?

I meant this one, if the LLQRM can get in with 100% local procuction, i don get the reason y it should not also consider the Naval variant, and if the things are right, it just a matter of time the French offer that too ….

click here for Larger Image

larger one

after the French torpedo was made inefective by the Russians, it seems like they are putting all anger on the MiG-29Ks, blasting them with VL Mica. Or do they seem a possiblity of an Indo-French conflict ???…. hehe …..

Blackcat, the contest is between (VL_Mica) -vs- (Python4+Derby=Spyder).
the max range against fast movers of either system is around 10km, so point defence only.

imo vl_mica is going to win this, because its already deployed on ships (?)

.Yeah i know, but the French have got the Naval variant too, and i wud love to see it get in rather than the $astardly Isreli stuff … atleast not untill the $astard Sharon extradiate the 7 Russians thiefs who is hiding in Israel.

——–

Hey and did u guys watch the recent visit of Putin to Israle?? …. well one thing that i cud confirm from it was that, no Sharon don have the backbone to confront Putin … or atleast he don wanna confront the KGB man as cud be seem from his posture after the ‘press meet’ …. and I loved that the Blah Blah channel had to withdrwa that footage after showing it for once or twice. Till then i was of the feeling that he was the unshakable man, whith a cool ‘reception’ to the guys he meet, which earlier i personally confered on Collin Powell for his coolness. But he shattered it with his meeting with Sharon when his trademark attitude missed some steps when he was with Sharon. And it was like – the Local Lion met a Bigger one! …. but after the recent meeting, I cud see that the Bigger Lion met an even Bigger one!

And Guys, i got some new plans for Tejas LCA ….. hope u guys don mind (a bit dry dream) .. will post that some time later on BR, if the Admin is accomodative …. BTW, the wet season has started with almost all day pouring here, down in South …

damn, 18 pages …. well no time to plunge into it now ….

well as for me, I believe in the version abt the collision, and the torpedo affair now cud be to put the blame again on the Russian’s poor training which lead the American/NATO sub to fire in self defence.

This whole thing can be taken parallel to what the Tu-144 met at Paris. All were blaming the Soviets when the hardest of the hardlners even if demanded to ‘show-off’ , no pilots wud show-off greater than from what he can maintain his posture. But the Tu-144 thing was ‘dealt-with’ by the govts which had more likely to do with the French – Mirages – fault which was tracking the Tu-144 and did not inform the Russians.

And this same thing is what I belive is the case with the Krushk, the Americans surely bumped into it, which caused the torpedoes/weapons to explode giving no chance to the crew to escape. Abt the rumoured $10billion, it cud be the deal which was made to keep the ‘boiling poinnt’ under wraps which otherwise mnight have created an enormous anti-American wave inside Russia, and the first of those casualties wud have been the ‘moles’ inside.

Moreover the CKB-Rubin have been maintaining abt the collision theory, even though it wont be any more embrassing/insulting for a Design Bureau to say that their prestegious design went down after a collision with a foreign sub.

The Soloviev D-30F6 was designed at Perm by a team led by Soloviev himself and since 1989 by Yuri Reshetnikov) with development beginning in 1972. The team was formed by two companies, Aviadvigatel and Motorostroitel. Development was finally completed in 1980. The engine is manufactured at Perm’s Motorstroitel works, and is claimed to be a derivative of the same D-30 engine that is used to power the Ilyushin Il- 62M and Tupolev Tu-154M. The bypass turbofan gives an excellent specific fuel consumption in the cruise, while the bypass flow around the engine’s inner core reduces thermal stresses on the engine. In this context, the 5 kg (11 lb) of silver used to give a reflective coating to MiG-25 engine bay heat shields has been dispensed with on the MiG-31. One unique feature of the D-30F6 is the use of small suction relief doors on the moving parts of the engine nozzles to eliminate pulsing in the exhaust gases.

The engine consists of seven modules, six of them replaceable. The first is an inlet guide vane module, with the others being the five-stage low pressure compressor, the mixer case, the afterburner, the exhaust nozzle, front and rear gearboxes, and a base module with the 10-stage high pressure compressor and combustion chamber, first stage nozzle vanes, high and low pressure turbines (both two stage) and rear bearing. The engine has a mass flow of 150kg (330 lb) per second and an inlet diameter of 102 cm (40 in). The D-30F6 features an integral heat exchanger using fan bypass air to cool air drawn from the compressor which in turn cools the high- and low-pressure turbines. A turbine overspend protection system is fitted, along with an exhaust temperature limiter. Full authority digital engine controls are fitted, with a data recording system. The new engine was specified for the MiG-31 in order to improve range, since this was the key performance parameter for which an improvement over the MiG-25 was demanded.

The new powerplant necessitated some structural modifications, and the opportunity was taken to increase internal fuel capacity to 19700 liters (4,333 Imp gal) (some estimates suggest 20380 liters/4,483 Imp gal). This, together with the lower specific fuel consumption of the D-30F, raised supersonic range to 2135 km (1,327 miles) on internal fuel, or to 3310 km (2,057 miles) at subsonic speeds. Increased weight reduced operational ceiling to 21900 m (71,850 ft).

well i didn’t knew that the D-30F6 had FADC.

anyone with more info on the engine for the MiG-31M, which Garry had said with an additional 1 tonne thrust??