No abstract

In order to further develop technologies to reduce noise emissions of aero engines, an understanding of the noise propagation through compressor blade rows of modern turbofan engines is of major importance. To enable more detailed experimental investigations of the sound propagation in aero engines, engine components or stages have to be scaled for an installation into test rigs that allow for experiments under acoustically optimized boundary conditions. The main focus of the present work is thus to discuss a scaling approach that ensures both aerodynamic and aeroacoustic similarity between a given test rig and engine. For that purpose, a stator row of a four-stage high-speed axial compressor (4AC) based on the test rig at the Institute of Turbomachinery and Fluid Dynamics (TFD) at the Leibniz University Hanover is scaled to fit into the TFD's Aeroacoustic Wind Tunnel (AWT). Numerical investigations based on multiple modeling approaches are performed to verify a similar aeroacoustic behaviour in both test rigs. Reynolds-Averaged Navier-Stokes (RANS) and Unsteady-RANS simulations are carried out to assess the aerodynamic characteristics of the blade rows. The aeroacoustic modelling consists of simulations with an Euler acoustic solver to compare the modal transmis-1 The presented work was divided equally between the Institute of Turbomachinery and Fluid Dynamics in Hanover and the Mechanical Engineering Department in Sherbrooke

To date, design processes for electrically powered compressor are mainly based on separate processes for each individual component. Whereas the blading is often designed by an integrated aerodynamic and mechanical design optimization, additional components such as the electrical machine are usually not included. These approaches neglect the interactions of the individual components, which can influence the system performance. This paper demonstrates a multidisciplinary design approach, combining an optimization approach for a compressor stage and an electrical machine. The automated optimization process is based on an evolutionary algorithm, evaluating each individual of a population in terms of aerodynamic performance, structural integrity and performance of the electrical machine. This approach is applied to the design of a mixed-flow compressor for active high-lift applications in aircraft. The results suggest that the overall system efficiency is mainly influenced by the compressor stage, whereas the system mass is dominated by the electrical components which highlights the need to combine both optimization approaches. Key design parameters of high power-density electrical-machine designs are identified. A comparison between a previous compressor-only optimization and a new design based on the new multidisciplinary optimization confirms the improvements the latter optimization approach yields.