Авіаційно-космічна техніка та технологія (Aug 2024)
Simulation of flow in the fan stage of a turbofan engine
Abstract
The subject of this research is the working process of the axial fan in a turbofan engine. The objective of this research was to investigate the fan impeller of a turbofan engine. The purpose of this work was to determine the dependence of the degree of pressure ratio on the air mass flow rate. In order to achieve this goal, the following tasks were performed: simulate the flow in the fan of a turbofan engine; to evaluate the visualization of the flow lines of the working body during the study of the flow over a certain range of rotation frequencies. During the study of the flow in the fan stage, a numerical experiment method was applied. Flow modeling was carried out by solving the system of Navier-Stokes equations, which were closed by the SST turbulent viscosity model in the ANSYS Student software environment. For modeling, a mesh with boundary layer adaptation was created with a number of 1199803 elements and 331685 nodes. This paper presents the results of modeling the flow in the fan stage of a turbofan engine. Results: a series of flow rate characteristics was obtained for the range of relative rotation frequencies from 70% to 100%. Studies have shown that the greatest pressure ratio was recorded at a relative rotation frequency of 100% - 1.45; the smallest value at 85% is 1.21. The flow lines in the inter-blade channel of the fan impeller were evaluated. At different rotation frequencies and with the same air consumption, the flow around the fan impeller exhibits a different character. The rotation frequency significantly affects the intensity and location of vortex formations. Among the considered options, the lowest intensity of vortex formation was observed at a relative rotation frequency of 70%. The scientific novelty and practical significance lies in the fact that new data on the flow characteristics of the impeller of the axial fan of a turbofan engine with a high bypass ratio were obtained by the method of a numerical experiment, and the results made it possible to generate initial data for further research on improving the fan characteristics.
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