par Enache, Adriana 
Président du jury Parente, Alessandro
Promoteur Hendrick, Patrick
Co-Promoteur Beeck, Jeroen van
Publication Non publié, 2025-04-16
Président du jury Parente, Alessandro
Promoteur Hendrick, Patrick
Co-Promoteur Beeck, Jeroen van
Publication Non publié, 2025-04-16
Thèse de doctorat
| Résumé : | Atmospheric icing is an important safety and efficiency issue for many industries such as manned aviation, unmanned aerial vehicle (UAVs) operations, and wind energy production. Icing on airframes increases mass, clogs up instrumentation, and degrades aerodynamic performance by increasing drag, reducing lift and anticipating stall. To limit these effects icing research is conducted to develop ice mitigation systems. However, these systems usually imply high energy costs and must be adapted to the requirements of each industrial application. This project focuses on the fundamental study of the ice removal mechanisms from airfoils by means of electro-thermal ice protection systems (ETIPS) de-icing. The goal is to investigate the technique’s limitations, ice shedding and runback icing, in order to propose ways to increase ETIPS’s energy-efficiency and applicability to icing-affected industries. Ice shedding poses safety risks and can produce damage to the airframe’s surface or its engines. Runback ice occurs beyond the ETIPS protected areas and induces aerodynamic penalties. This project presents an idealized fast-computational model that can predict the ice shedding time in function of ETIPS operational parameters and atmospheric conditions. Using this model, one could rapidly simulate and adapt ETIPS’s de-icing parameters to reach an acceptable ice shedding time with improved energy efficiency. Moreover, the fundamental study of ETIPS’s de-icing mechanisms presented in this work offers an increased physical understanding of the process and its limitations. Additionally, two ice accretion measurement techniques for 2D ice shapes were developed to offer fast and accessible measurement methods for icing research. ETIPS de-icing experimental campaigns were conducted in icing wind tunnels (IWT), in two configurations, an idealized and a realistic one. The idealized configuration of ETIPS equipped flat plates with frozen ice models was used for an ice shedding time parametric study and fundamental investigation of its mechanisms. A phase change code was developed and employed for computing the water layer thickness at the experimentally measured ice shedding time. The coupled numerical-experimental results showed an empirical ice shedding threshold, which was coupled with the phase change solver to generate the idealized ice shedding prediction model. The model was experimentally validated by Sonaca and it was implemented in their icing solver. Outlier cases for which the idealized model could not predict the ice shedding time were investigated by means of high-speed flow visualizations. Four types of ice shedding mechanisms were observed, from which the ones based on ice cracking-shedding were too complex to be predicted by the developed model. Several ice shedding phenomenological hypothesis presented in literature were experimentally validated on the idealized set-up.The ETIPS de-icing experimental research on the realistic configuration of an iced fixed-wing UAV airfoil was conducted in collaboration with the research team of the Norwegian University for Science and Technology (NTNU) and UBIQ Aerospace. A parametric study over the ice shedding times coupled with anti-icing tests showed the most energy-efficient ETIPS configuration. This was also found to generate the most extended runback ice formation. An additional ice removal mechanism was observed. Ice accretion experiments were conducted and two image-processing based measurement techniques for 2D ice shapes were developed and validated. |
