МЕТОДИКА ТОПОЛОГІЧНОЇ ОПТИМІЗАЦІЇ ВЕНТИЛЯТОРА ТУРБОРЕАКТИВНОГО ДВОКОНТУРНОГО ДВИГУНА

The article presents a methodology for the topology optimization of a turbofan engine fan using a two-row fan blade as an example. The relevance of the study is determined by the need to reduce the mass of aircraft gas turbine engine components while maintaining their strength, stiffness, and operational capability under aerodynamic and mechanical loads. Fan rotor blades are subjected to airflow loads, centrifugal forces, bending moments, and torsional effects; therefore, any structural weight reduction must account for the complex stress-strain state. The object of the study is a two-row fan blade of a turbofan engine. The subject of the study is the methodology for the topology optimization of a two-row fan blade, considering aerodynamic loads, the stress-strain state, and strength constraints. The aim of the work is to develop a sequential topology optimization methodology for a two-row fan blade to reduce structural mass without critical deterioration in its strength characteristics. The research tasks include developing a geometric model of the two-row blade and the computational domain for flow simulation, and performing CFD calculations to determine the flow pattern, pressure distribution, and aerodynamic loads on the blade surface. The obtained loads are transferred to the Static Structural module for static strength analysis. In the structural analysis setup, material properties, blade fixation conditions, load-transfer characteristics, and torque transmission through the root section are considered. The main evaluation parameters were equivalent von Mises stress criterion, total deformation, defined as the resultant displacement of the finite element model nodes, the structural mass, and the safety factor. Based on the results obtained, the blade regions of lower structural significance were identified. These regions can be removed without significantly impairing the structure's load-bearing capacity. The study was conducted via numerical experiment in the Ansys Workbench Student software environment. The problem was solved using CFD, FEM, and topology optimization methods. As a result, a topology optimization methodology for a two-row fan blade was developed. It combines the determination of aerodynamic loads, construction of a finite element model, topology optimization, and subsequent strength verification of the obtained structure. The developed methodology enables the determination of a rational material distribution within the blade volume while preserving the external aerodynamic contour, the root section, the leading and trailing edges, and other functionally important elements. The application of the proposed methodology reduces structural mass while maintaining acceptable stress levels and the required safety factor. This confirms the feasibility of using the methodology to design and improve gas turbine engine fan blades for aircraft. The scientific novelty and practical significance of the study lie in the development of a computational methodology for the topology optimization of a two-row fan blade that accounts for aerodynamic loading and the stress-strain state. The practical significance lies in achieving a lightweight blade structure with an internal cutout that preserves the main aerodynamic contour while maintaining the required load-bearing capacity. The proposed methodology can be used at the preliminary design stage of advanced aircraft gas turbine engine fans. Further research should focus on analyzing natural frequencies and mode shapes, fatigue strength, aeroelastic stability, and the technological feasibility of manufacturing the optimized internal cavity of the blade.