Berezovskyi Y. Quality assurance of wide-chord fan blades for turbojet bypass engines for improving performance

The object of research is the manufacturing process of wide-chord fan blades production for turbojet bypass engine; the purpose of the research is to provide high performance characteristics of a wide-chord fan of a turbojet bypass engine by forming a rational combination of the quality parameters of the surface layer of the wide-chord working blade airfoil at the forming and finishing stages of its machining, that increase durability and reduce the level of vibratory stress; methods of research - methods of engineering mechanics for studying the physical and mechanical parameters of the surface layer and strength characteristics of specimens, numerical methods of elasticity theory for determining the stress-strain state under different loading conditions, methods of mathematical statistics for the processing of test results, methods of trials of aviation engines for determining the performance characteristics ; results - a comprehensive theory of manufacturing a wide-chord fan rotor blades of a turbojet bypass engine is developed; Novelty - for the first time the regularities of the finish milled surface layer quality parameters dependence on the values of the federates and cutting speeds were obtained, as well as their influence on the durability of the wide-chord fan rotor blades after their strengthening processing by various technological methods, which made it possible to develop a manufacturing process for their production; the parameters of the dynamic damper and the damping parameters of the wide-chord fan rotor blade oscillations were determined during its processing with high-speed milling, which allowed to reduce the level of vibrations, and, consequently, the roughness of the machined surfaces; for the first time, the conditions for the appearance of a bending-twisting flatter and resonant oscillations of blades with a high level of dynamic stresses have been determined experimentally, which made it possible to reduce the level of dynamic stresses and eliminate the flatter to offer variants for finishing the airfoil of the wide-chord fan rotor blades by changing the chord of the peripheral sections of the blades from the side of the incoming edge; a comparative analysis of the characteristics of the fan with working blades with midspan damper and a fan with wide-chord rotor blades is made, that allowed to substantiate the performance characteristics; the degree of implementation - the results are implemented in the educational process of the Aviation engine technology department of the Zaporizhzhya National Technical University and in manufacturing process of the “Motor Sich” Joint Stock Company; industry of use - aircraft engines manufacturing.