Background and Motivation
Galloping is a large-amplitude, low-frequency aeroelastic instability that may develop on overhead transmission lines under specific combinations of wind conditions and ice accretion. Accurate prediction of galloping requires reliable aerodynamic data, including force coefficients and flutter derivatives, which strongly depend on the geometry of the ice accretion and the conductor bundle configuration. Although several experimental studies have been conducted over the past decades, available datasets remain limited and often focus on simplified conductor arrangements. Wind tunnel testing therefore plays a key role in improving the characterization of iced conductors and supporting the development of more accurate galloping prediction models.
Objectives
The main objectives of this thesis are:
- Review the existing literature on wind tunnel testing of iced conductors and conductor bundles.
- Design and prepare an experimental setup for aerodynamic testing in the wind tunnel.
- Perform experimental measurements on conductor bundles with different ice accretion geometries.
- Determine the aerodynamic force coefficients and flutter derivatives required for galloping analysis.
- Process and analyse the experimental data.
- Use the measured aerodynamic parameters to perform quasi-steady numerical simulations of galloping response.
Methodology
The proposed research will involve:
- A comprehensive literature review on galloping mechanisms, ice accretion geometries, and experimental testing techniques.
- Design, assembly and calibration of the wind tunnel experimental setup.
- Wind tunnel testing of iced conductor bundle models under different flow conditions.
- Measurement of aerodynamic coefficients and flutter derivatives.
- Processing and validation of the experimental data.
- Numerical simulations based on the corrected quasi-steady galloping theory using the experimentally derived aerodynamic parameters.
- Discussion of the results with reference to current research and engineering practice.
Expected Outcomes
The thesis is expected to:
- Provide new experimental aerodynamic data for iced conductor bundles.
- Improve the understanding of the influence of ice accretion geometry on galloping behaviour.
- Assess the applicability of quasi-steady galloping prediction methods using experimentally derived aerodynamic parameters.
- Contribute to ongoing research on the aeroelastic behaviour of overhead transmission lines.
Prerequisites
Basic knowledge of fluid mechanics, structural dynamics and wind engineering is recommended. Familiarity with data analysis and numerical modelling tools (e.g. MATLAB or Python) is considered an advantage.
Contact
Federico Zanelli 📧 federico.zanelli@polimi.it