12th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
Computational fluid dynamics (CFD) simulations are often used in the design process of s-shaped engine inlet ducts. The results of such simulations need to be compared with experimental data for validation purposes. In contrast to turbulence models, the numerical boundary conditions for turbulence (i.e. intensity and length scale) are rarely considered when CFD for s-duct simulations are validated. However, during earlier work at the Institute of Jet Propulsion it was found that numerical turbulence settings can have a significant influence on the aerodynamics in an engine inlet system. Hence, an experimental setup was established to evaluate these findings. The experimental results show that increasing free-stream turbulence significantly influences the internal duct flow and thus the distortion at the inlet plane of the compressor system. For the presented test case the mean total pressure loss at the compressor intake plane increases, which may have has a negative effect on compressor performance. On the other hand the distortion described by common descriptors is reduced, which is generally advantageous in terms of compressor stability. The results from the numerical simulations qualitatively agree with the experimentally obtained data.