Dynamics and Aerodynamics of Structures
Dynamics and Aerodynamics of Structures Research Group
Description of Activities
Research activities focus on the dynamics and aerodynamics of such engineering structures as suspended cables and transmission line conductors or wind turbine blades. These structures are exposed to dynamic loads due to several reasons including wind, icing conditions, or other external intervention. Natural phenomena may result in harmful vibration that reduces the range of operation and lifetime of these structures, which justifies the effort to develop solutions for diminishing the undesired consequences of the vibration. Models are developed to understand the conditions of high-frequency and high-amplitude cable motion, and to assess the damages that such vibrations may cause. This activity contributes to proposing solutions in order to attenuate the vibration, and consequently, protect the structure. Application of vibration control may lead to irregular cable motion that requires the detailed study of the dynamics of such systems. Further models are constructed to examine the aerodynamics of bare and iced wind turbine blades. Such study helps predict the effects of icing conditions on the wind turbine performance, and contributes to improving the blade profile so that the influence of extreme weather conditions is minimized.
Research Interests
The research activity described above involves the following tasks:
- Numerical and experimental study of vortex-induced vibration of a flexible cable with geometric nonlinearities;
- Application of vibration control in order to reduce amplitude of cable vibration and the dynamic forces acting on the cable
- Study the dynamics of digitally controlled cable vibration including sampling delay and backlash at the driving
- Numerical simulation and wind-tunnel experiments of icing of a wind turbine blade with varying ambient conditions
- Aerodynamic study of iced wind turbine blades, exploring the effects of blade shape on the profile of ice accretion, on the aerodynamic forces and on the wind turbine performance
Research/service concepts/Methodology
Mathematical modelling and numerical study are supported by software available including Matlab, Ansys Fluent, Ansys Fensap-Ice, but own codes are also developed and applied. Equipment available in the Dynamics Laboratory for experimental study includes a small-scale model of a transmission line equipped with load cells and displacement sensors, with the possibility of attaching a shaker to apply excitation, and with removable weights for load shedding tests. The Fluid Dynamics Laboratory includes an icing wind tunnel with sensors to measure flow parameters and with a Phase Doppler Particle Analyzer to measure velocity and size of droplets or particles in two-phase flows.
Research Staff
- Prof. László Kollár, Full Professor, head of group
- Dr. Tibor Borbély, Associate Professor, senior researcher
- Dr. Dániel Dorogi, Research Fellow, senior researcher
- Kristóf Lajber, Assistant Lecturer, senior researcher
- Ibrahim Kipngeno Rotich, PhD student, junior researcher
- MSc and BSc students involved in short projects
Projects
The research group is involved in the following projects:
- Security and data protection in the fields of material technology, industry 4.0 and energy engineering (2022-2025, pillar 3 in the project no. TKP2021-NVA-29 “Protection of high integrity national services and industrial infrastructures using cybersecurity, technological and legislative instruments”)
- Vibration control of transmission lines (2022-2023, “Mecenatúra” project no. 141334)
- Innovative processing technologies, applications in energy engineering, and wide-range microstructure investigation techniques (2017-2021, workgroup 5 in the project EFOP-3.6.1-16-2016-00018 “Improving the role of research + development + innovation in the higher education through institutional developments assisting intelligent specialization in Sopron and Szombathely”)
5 important publications in the field
- Moawad, A., Kollár, L. E., Bognár, A., Borbély, T., Lajber, K. (2023) ‘Buckling of interphase spacers during vibration following ice shedding‘, Cold Regions Science and Technology, 213, pp. 103904:1–103904:10. https://doi.org/10.1016/j.coldregions.2023.103904
- Kollár, L. E. (2023) ‘Dynamics of digitally controlled forced vibration of suspended cables‘, Meccanica, 58, pp. 25–42. https://doi.org/10.1007/s11012-022-01627-0
- Kollár, L. E. (2022) ‘Ice-shedding-induced vibration of conductors with active vibration control‘, Cold Regions Science and Technology, 196, pp. 103504:1–103504:10. https://doi.org/10.1016/j.coldregions.2022.103504
- Meng, Y. and Kollár, L. E. (2021) ‘Dynamic analysis of electrical vibration absorbers for suspended cables‘, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 235(24), pp. 7445–7455. https://doi.org/10.1177/09544062211005801
- Kollár, L. E. and Mishra, R. (2019) ‘Inverse Design of Wind Turbine Blade Sections for Operation under Icing Conditions‘, Energy Conversion and Management, 180, pp. 844–858.
Infrastructure