AERODYNAMIC AND AEROACOUSTIC PERFORMANCE OF ULTRA LOW COUNT FAN OUTLET GUIDE VANES

摘要

It has been an aim at Volvo Aero to develop a fan outlet guide vane (OGV) based on what is called Ultra Low Count (ULC). The goal is to significantly reduce the broadband and tonal noise compared to a conventional fan OGV. The starting point was the work done within the FP7 framework programme VITAL where a Low Count (LC) OGV was designed and evaluated. The LC OGVs developed had a vane count close to that of the rotor and was cut-on at some operating points. Aerodynamic, mechanical and aeroacoustic studies were done. Within the DREAM and OPENAIR programmes the Low Count technology was then further developed into the Ultra Low Count technology. This technology involves an OGV count considerably lower than that of the rotor. An additional opportunity with the ULC OGVs is that the increased thickness adds the possibility to introduce acoustic treatment in the vanes by having acoustic liners inserted in them. The acoustic benefit of introducing acoustic liners in the OGVs will however not be presented in this paper. The present paper will focus on comparing the aerodynamic and acoustic performance of different OGV vane counts.