According to Rostec Aviation Cluster Industrial Director Anatoly Serdyukov, Russia’s state hi-tech corporation Rostec has conducted 16 flights of the fifth-generation Su-57 fighter jet to test its new second stage engine.
“Currently, the engineering bench tests of the advanced engine continue and the item is being tested on a flying laboratory. In October, another flight was performed to check the item’s characteristics in various flight modes, specifically, the operation of the vectoring jet nozzle and the oil system at negative overloads. Overall, 16 flights on a flying laboratory were performed,” Serdyukov reported.
The first flight of the Su-57 with the Product 30 engine was realized in December 2017th.
The engine will get a fully electronic automatic control system and ensure the fighter’s super-maneuverability, thrust-to-weight ratio, stealth characteristics and the ability to perform cruising flights at supersonic speed.
Currently, the Su-57 flies with an AL-41F1 engine (Product 117), which are typically equipped on Su-35 fighter jets.
The Su-57 fighter belongs to the conditional fifth generation, which indicates the presence of a number of characteristic requirements. One of the main requirements is the provision of cruising supersonic speed, including without the use of afterburners.
Existing engines (such as the AL-41F1) are not capable of providing such characteristics, and therefore the fighter jet requires a completely new engine.
The engine of the second stage for the Su-57 fighter (“Product 30”) was developed at the Lyulki Design Bureau under the direction of Evgeny Marchukov and in collaboration with other large Russian engine-building companies.
According to known data, “Product 30” is a dual-circuit turbojet engine with an afterburner. At the level of some basic ideas, it has similarities with older engines of the AL-31 and AL-41 families, but all of its units were developed anew and using modern technology.
The result of this was a noticeable increase in all the basic characteristics, allowing to attribute “Product 30” to the next generation of turbofan engines.
The engine has a typical architecture for its class with multi-stage high and low-pressure compressors, a combustion chamber and multi-stage turbines.
Behind the turbines are an afterburner and a nozzle with TVC (thrust vector control).
The compressor provides compression of the incoming air with a degree of 6.7, providing airflow up to 20-23 kg/s. The combustion chamber is equipped with a plasma ignition system installed directly on the nozzles.
Such tools ignite the fuel immediately after it enters the combustion chamber. Due to this, the optimal combustion mode is maintained, and the so-called flare – improper combustion of fuel accumulated in the engine. The temperature of the gases in front of the turbine ranges from 1950 to 2100 ° K. For comparison, in the serial AL-31F engine, this parameter does not exceed 1700 ° K.
According to open data, the maximum thrust of the Product 30 engine reaches 11,000 kgf, afterburning – 18,000 kgf. For comparison, the engine of the first stage AL-41F1 has a thrust of 9500 and 15000 kgf, respectively. Thus, the Su-57 aircraft, even with a maximum take-off mass exceeding 35 tons, will have a thrust ratio of more than one. With normal take-off weight, this parameter will reach 1.15-1.2.
It is to replace the AL-41F1 engine when it enters serial production. The “first stage” engine has been in serial production since 2018. The Product 30 engine is expected to enter serial production sometime in 2020.