Aerodynamic performance of chevron geometry trailing edge for a transonic axial compressor impeller

Abstract

Several studies present how serrated rotor blades mix wakes in order to attenuate noise levels. The current paper analyses how this geometry, applied on the trailing edge, affects the global parameters of a transonic axial compressor impeller. Innovative solutions tackling the rotor-stator interaction mechanism in an axial compressor for noise reduction include serrated trailing edges. Inspired by chevron nozzles, serrations can be transferred to the open-rotor concept in order to reduce tonal noise. Throughout the study we will be focusing on aerodynamic loss estimation while being mindful of the mechanisms which lead to rotor-stator interaction noise, without assessing its per-se effectiveness for noise mitigation. Owing to its qualitative experimental data availability, NASA’s Rotor 37 was chosen as a baseline. A set of fully viscous 3D simulations, using the SST k omega turbulence model and RANS, was carried out to this effect. Spatial discretization was made using a fully structured pre-mesh in order to optimize resolution and accelerate convergence. Full-factorial samples were generated for the geometric variations in order to capture the aerodynamic implications of this concept. Overall, the analysed case provides promising perspectives, pending optimization studies and experimental tests thereof.