ABDELKADER, M. Aerodynamické možnosti prodyšného povrchu profilů [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2025.

Posudek vedoucího

Popela, Robert

Mr. Abdelkader elaborated work in the field of active flow control which is now rapidly developing technology. He carried out in-depth research on the application of AFC for mitigating the negative effects of flow separation. His analysis, based on advanced CFD tools, explored two potential devices for enhancing airfoil performance. He assessed not only the aerodynamic efficiency but also the energy demands of these concepts and estimated their overall effectiveness. In his thesis, Mr. Abdelkader adopted a constructive approach, expanding his knowledge of CFD beyond the foundational level taught in lectures through independent study. It is worth noting that the thesis topic is more research-oriented than a typical engineering problem, and he successfully adapted to the complexity of this challenge.

Posudek oponenta

Kaspar, Štěpán

The thesis addresses the topic of Active Flow Control (AFC). AFC is considered as a replacement for turbulators. The objective of the work was to compare these two approaches. In the first part, the author introduces the fundamentals of the boundary layer and the current state of knowledge in the field of AFC, focusing on its potential to influence boundary layer behavior. In the second part, the author describes the applied methods and presents an initial analysis. Using the Xfoil tool, an analysis of the LS(1)-413 MOD airfoil was carried out, which is also used in the subsequent analyses. However, the author uses Re = 500,000 for this analysis. These conditions apply only to the Xfoil results. The insights gained here do not significantly contribute to the remainder of the thesis, as the airfoil is later evaluated under different conditions. In the fourth part, the CFD model is described and calibrated through comparison with wind tunnel measurements. The boundary conditions correspond to Re = 2,000,000. The next section explores various AFC configurations and their effects on the resulting aerodynamic characteristics. The results are described in great detail. After analyzing the initial AFC system, the author identifies its low efficiency and proposes a new solution involving tangential blowing on the upper surface of the airfoil. In the final section, the author conducts an energy-based comparison between the clean airfoil and the airfoil equipped with AFC. This comparison is carried out to a good standard and includes a broad range of relevant factors. Although the thesis contains a separate literature review chapter, chapters 5.1, 5.3.1, and 6.1 also function as literature summaries. This structure is somewhat confusing, and it would be more appropriate to consolidate all literature discussions into the dedicated review chapter. The thesis aimed to answer the question regarding the comparison of turbulators with AFC. Unfortunately turbulators are only mentioned in the research without any investigation either with Xfoil or CFD. AFC is only compared by pure profile configuration. The thesis would benefit from a visualization of the flow around the airfoil with AFC, clearly illustrating the induced changes. Currently, the impact of AFC is demonstrated only through lift curves, which may not provide a complete picture.The extensive description of the graphs makes reading very difficult, unclear and does not provide any added information. The thesis brings several new insights to the field of AFC. I recommend the thesis for defense.

eVSKP id 166114