Scoop optimization : A preliminary study

Abstract: Scoops are important parts in an aircraft engine design, as they provide airflowto different equipment and subsystems. The optimization of such a component isessential in order to find a design that can perform properly within a range of flightconditions, with a minimum impair of main flow aerodynamic performances. Scoopdesign methods are generally based on previous experimental results and are usuallyconstrained by the limited space available. The studied configuration concerns theflush scoop located inside the secondary flow of turbofans which provides flow fora turbine cooling equipment. Depending on flight conditions and engine workingpoint, this scoop will experience various flow regimes, from low mass flow rates tochoke flows. Therefore, the study of several scooped mass flow rates is mandatoryto extract the scoop behaviour. The thesis concerns the preliminary step beforea 3D CFD optimization : a study of influence is run on the baseline geometry inorder to investigate the robustness of the solution computed using different methodsand to determine the parameters to be optimized. Firstly, the full post-processingmethodology is defined to properly evaluate the performance of a design (scoopefficiency, induced pressure losses). A second step consists in analysing the abilityof CFD solvers to capture the different flow behaviour. This point is addressed bycomparing solvers (Fluent, elsA, PowerFLOW), meshes (structured, unstructured)and turbulence models. The third step deals with the optimization strategy definitionto improve the scoop design and thus the engine fuel consumption.