Simulation of flow in the fan stage of a turbofan engine

Andrii Duliepov

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.

Keywords


pressure ratio; air mass flow rate; gas turbine engine; turbofan engine; fan; impeller; blade; boundary layer; turbulent viscosity model; numerical simulation

References


Balli, O., & Caliskan, H. Turbofan engine performances from aviation, thermodynamic and environmental perspectives. Energy, 2021, vol. 232, article no. 121031. DOI: 10.1016/j.energy.2021.121031.

Abdelghany, E. S., Sarhan, H. H., El Saleh, A., & Farghaly, M. B. High bypass turbofan engine and anti-icing system performance: Mass flow rate of anti-icing bleed air system effect. Case Studies in Thermal Engineering, 2023, vol. 45, article no. 102927. DOI: 10.1016/j.csite.2023.102927.

Merculov, V., Kostin, M., Martynenko, G., Smetankina, N., & Martynenk, V. Improving the accuracy of the behaviour simulation of the material of the turbojet aircraft engine fan rotor blades in the event of a bird strike by using adapted finite element computational models. Materials Today: Proceedings, 2022, vol. 59, pp. 1797-1803. DOI: 10.1016/j.matpr.2022.04.381.

Chen, H., Cai, C., Jiang, S., & Zhang, H. Numerical modeling on installed performance of turbofan engine with inlet. Aerospace Science and Technology, 2021, vol. 112, article no. 106590. DOI: 10.1016/j.ast.2021.106590.

Sob, P., & Pita, M. Modelling and designing of a turbofan engine with more enhanced overall engine efficiency during operation. International Journal of Mechanical and Production Engineering Research and Development, 2021, vol. 11, pp. 333-350. ISSN (P): 2249–6890; ISSN (E): 2249–8001.

Briones, A., Caswell, A., & Rankin, B. Fully Coupled Turbojet Engine Computational Fluid Dynamics Simulations and Cycle Analyses Along the Equilibrium Running Line. Journal of Engineering for Gas Turbines and Power, 2021, vol. 143, article no. 061019. DOI: 10.1115/1.4049410.

Yao, Y., Zhang, X.-B., Zhang, M., & Wang, Z. Modeling and Cycle Parameter Matching of a High-Speed Variable Cycle Turbofan-Ramjet Engine. Journal of Engineering for Gas Turbines and Power, 2022, vol. 144, article no. 101003. DOI: 10.1115/1.4055214.

Zhornyk, O. V., Kravchenko, I. F., & Mitrakhovych, M. M. Udoskonalennya kharakterystyk kil'tsevoho vkhidnoho prystroyu aviatsiynoyi sylovoyi ustanovky z hvyntoventylyatorom [Improvement of characteristics of the ring input device of the aviation power plant with the screwfanter]. Aviacijno-kosmicna tehnika i tehnologia – Aerospace technic and technology, 2021, vol. 4sup2 (174), pp. 11-18. DOI: 10.32620/aktt.2021.4sup2.02.

Dulyepov, A. A., Hlobin, Ye. V., Kovtun, A. A., Khyzhnyak, M. V., Balalayeva, K. V. Testova zadacha modelyuvannya techiyi u stupeni kompresora Rotor 37 [Test problem of flow modelling in the Rotor 37 compressor stage]. Aviacijno-kosmicna tehnika i tehnologia – Aerospace technic and technology, 2023, vol. 4, pp. 73-78. DOI: 10.32620/aktt.2023.4.09.

He, T. T., Abdelaal, M. A. S., Zaman, I., Didane, D. H., & Manshoor, B. Airflow Analysis of Contra-Rotating Fans Performance by Numerical Simulation. Technological Advancement in Instrumentation & Human Engineering. ICMER 2021. Lecture Notes in Electrical Engineering, 2021, vol. 882, pp. 483-495. DOI: 10.1007/978-981-19-1577-2_36.




DOI: https://doi.org/10.32620/aktt.2024.4sup1.04