Russia is continuing its program to replace commercial devices of “Western” origin. The new Yakovlev SJ-100 is currently in the middle of a testing phase, notably within the confines of the TsAGI, the central institute of aerohydrodynamics where the device is notably subjected to stress tests. Meanwhile, the motor integration of the device is also being tested, this time in a wind tunnel and still at TsAGI.
The Yakovlev SJ-100 at TsAGI
In Russia, the SJ-100, or rather the so-called “substitute” version of the original aircraft, the Yakovlev SJ-100, is the subject of extensive tests. The experimental prototype of the new SJ-100 made its first flight last August. The TsAGI, or Central Institute of Aerohydrodynamics, makes a significant contribution to testing, particularly to research into aerodynamics, resistance and life cycle. It is within the walls of the institute that the second phase of life cycle testing of the airliner is currently being carried out under a contract with Yakovlev PJSC, since the manufacturer will be responsible for production domestically built SJ-100s.
Analyze the structural behavior of the aircraft
TsAGI focuses on collecting data regarding the aircraft’s structural behavior under repeated stresses to determine the aircraft’s limitations in terms of flight hours and calendar time. “Laboratory conditions simulate the full life cycle of the aircraft, modeling random combinations of all potential loads that may affect the aircraft in actual operation – such as control maneuvers, turbulence, takeoff and landing, and cruising flight,” explains Stanislav Dubinsky, head of structural life of aircraft, at TsAGI.
Fatigue tests
To simulate stresses, scientists use independently digitally controlled hydraulic cylinders which increase the speed of testing and the accuracy of results. The structural response is measured using a special system of strain gauges; loading, collection and processing of data are controlled using TsAGI software. In early fall, fatigue testing of the aircraft was completed, equivalent to 12,000 laboratory flights, and revealed no structural defects in the aircraft airframe. By the end of the year, the second phase will be completed, which is 24,000 flight cycles, which is expected to confirm the high initial service life of the aircraft replaced by an imported aircraft.
Remotorization
The Yakovlev SJ-100 is intended to be re-engined. This is why the Russian engine manufacturer United Engine Corporation successfully carried out the first stage of certification tests for the PD-8 turbojet (Perspektivnyi Dvigatel, engine of the future, (of) 8 t thrust), at least its power generator. gas, intended for the new version SSJ. A specific ground test bench was used to simulate typical aircraft engine operating conditions, rendering altitudes up to 12,000 m. The gas generator consists of a high pressure compressor, a combustion chamber and a high pressure turbine which drives the propulsion system. The test facility was provided by the Central Institute of Aviation Engines named after PI Baranov (part of the National Research Center known as the Zhukovsky Institute) and confirmed the aerodynamics of the compressor. Motor integration is now the subject of wind tunnel tests; more precisely, the behavior of the pylon-nacelle tandem is currently being analyzed by Russian scientists.
