I'm looking for information, particularly technical specifications, of the Viper Mk 633-47 afterburning turbojet.
This was developed for use on the Yugoslav J-22 and Romanian IAR-93 aircraft.
It appears to be a Viper Mk 632, as licence produced in Yugoslavia, but obviously fitted with a newly designed afterburner.
It would be interesting to see how it compared technically to the J-85 afterburning engine as used in the F-5 aircraft, which it seems to be a close competitor to....in performance not timeline.
But there seems to be a complete lack of information out there on it.
Things such as diameter, length, weight, SFC etc would be interesting to see.
The main difference between Viper 633-41 (Yugoslavia) and 633-47 (Romania) is that the latter has an anti-icing system.
Basic dimensions/performances:
Inlet diameter of air intake casing = 490,22 mm
Max. width/height of the engine = 708 / 843,5 mm
Length of the base engine = 2433 mm
Length of the reheat section (nozzle open) = 2189 mm
Max. weight of the engine = 431,5 kg
Max. weight of reheat section = 135 kg
Max. RPM = 13760 rpm
Turbine entry temperature: approx. 1243 °K
Air mass flow = 26,8 kg/s
Compressor pressure ratio = 5,9
Min. thrust without reheat = 1693 daN / with reheat = 2161 daN
Max. SFC without reheat = 1,040 kg/daN h / with reheat = 1,866 kg/daN h
Max. JPT without reheat = 750 °C / with reheat = 760 °C
The following reheat accessories are not shown in the cross section: Low pressure reheat fuel filter
Air turbo pump (provides sufficient fuel under all operating conditions to meet the reheat fuel system requirements) Flow control unit (supplies correctly metered fuel for re-heat operations) Shut off valve (prevents a fuel flow to the reheat burners when reheat is selected 'OFF') Pressure maintaining valve (maintain a reheat system delivery pressure above the minimum pressure requirement for correct fuel flow metering in the reheat Flow Control Unit) Hot streak accumulator (provides shot of metered fuel to non-return valve injectors) Non-return valve injector (2 off) (directs the shot of fuel from the Hot Streak Accumulator into the engine gas stream to initiate light-up of the reheat fuel system) Nozzle actuation ram (4 off) (hydraulically operated unit designed to provide the force necessary to move the variable engine exhaust nozzle mechanism) Nozzle control valve (Micro-jet) (regulates the nozzle area relative to reheat or altitude conditions, thereby maintaining the required pressure differential across the turbine necessary to provide optimum combustion efficiency) Air control valve (controls and regulates the bleed air flow from the compressor to the air turbo pump)
Inlet diameter of air intake casing = 490,22 mm
Max. width/height of the engine = 708 / 843,5 mm
Length of the base engine = 2433 mm
Length of the reheat section (nozzle open) = 2189 mm
Max. weight of the engine = 431,5 kg
Max. weight of reheat section = 135 kg
So..the engine itself with afterburner is larger than the afterburning J85, particularly in length and weight.
4.6m long and weighing in at 566kg.
The french helped yugoslavia to develop afterburnig somewhere the power of the engine was increased by 34 percent power of the engine.The F-5 had better aerodynamics and smaller wings and thin wings which makes less resistance. The Eagle is a heavier aircraft from f-5 for 1 ton J-22 was and modeled after a Tornado
The french helped yugoslavia to develop afterburnig somewhere the power of the engine was increased by 34 percent power of the engine.The F-5 had better aerodynamics and smaller wings and thin wings which makes less resistance. The Eagle is a heavier aircraft from f-5 for 1 ton J-22 was and modeled after a Tornado
Definitely aerodynamic differences.
To me, the J-22 looks inspired more by the Jaguar, in looks and role. 2 seat trainer and single seat attack. High wing, high intakes, twin wheel main landing gear...for operations from grassed strips.
It looks as if the design goal was a cheaper, lighter Jaguar type, about 3/4ths the weight, size, and carrying capability.
I always thought it was an intelligent foray and incremental step up in their design pathway and capabilities.
I am aware it was originally a design concept with a more powerful engine and supersonic performance.
I wonder whether the more powerful Viper 680, but with afterburning was ever considered..
To me, the J-22 looks inspired more by the Jaguar, in looks and role. 2 seat trainer and single seat attack. High wing, high intakes, twin wheel main landing gear...for operations from grassed strips.
It looks as if the design goal was a cheaper, lighter Jaguar type, about 3/4ths the weight, size, and carrying capability.
Definitely inspired by the Jaguar. Plus, both countries have had good connections with France in the time of interest.
Both countries were also painfully aware that their engines' production was in the state as it was (so either a Viper, or something from the Soviet Union), thus we have the Orao tailored for the available engines. That meant lower weight, lower payload weight, and usage of a thicker wing that was not outfitted with the excellent hi-lift devices that Jaguar had.
Definitely inspired by the Jaguar. Plus, both countries have had good connections with France in the time of interest.
Both countries were also painfully aware that their engines' production was in the state as it was (so either a Viper, or something from the Soviet Union), thus we have the Orao tailored for the available engines. That meant lower weight, lower payload weight, and usage of a thicker wing that was not outfitted with the excellent hi-lift devices that Jaguar had.
Yes..and both countries had single-engined advanced jet trainer designs following in the pipeline slightly below the IAR93/J22 in the IAR99 and G4 Super Galeb.
These used the same Viper engine, which both countries had taken out a licence to manufacture.
All very logical from a manufacturing, independence, and servicing/spares point of view.
Edit: It would be interesting to see if there was any cross-pollination of ideas or design features between the IAR99 and G4 Super Galeb actually...
The french helped yugoslavia to develop afterburnig somewhere the power of the engine was increased by 34 percent power of the engine.The F-5 had better aerodynamics and smaller wings and thin wings which makes less resistance. The Eagle is a heavier aircraft from f-5 for 1 ton J-22 was and modeled after a Tornado
The French had nothing to do with the development of afterburner. The entire afterburner system was developed by Rolls-Royce and Lucas Aerospace together with the Aviation Technical Institute from Belgrade.
There is an excellent article on the TangoSix website (https://tangosix.rs/2024/05/11/prvi...pa-do-modernizacije-jugoslovenskog-jurisnika/) commemorating the 50th anniversary of the first flight (31.10.1974.) of the ORAO.
Definitely aerodynamic differences.
To me, the J-22 looks inspired more by the Jaguar, in looks and role. 2 seat trainer and single seat attack. High wing, high intakes, twin wheel main landing gear...for operations from grassed strips.
It looks as if the design goal was a cheaper, lighter Jaguar type, about 3/4ths the weight, size, and carrying capability.
I always thought it was an intelligent foray and incremental step up in their design pathway and capabilities.
I am aware it was originally a design concept with a more powerful engine and supersonic performance.
I wonder whether the more powerful Viper 680, but with afterburning was ever considered..
Rolls-Royce offered the Viper 680-43 to Yugoslavia in the mid-80's as an upgrade to the Galeb G-4 (which uses the 632-46). The Viper 680-43 has up to 15% more thrust than the Viper 632-46.
A variant with an afterburner is also offered. That variant would have 14.5% more thrust on the afterburner than the Viper 633-41.
Then came the 90’s and the civil war in Yugoslavia . . .
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