Abstract
This paper describes the investigations carried out to examine whether unevenly spaced stator blades can be advantageously used to reduce the blade passing frequency tone generated by rotor wake interaction with the stators. Experiments were carried out on a single stage axial fan of 305‐mm diameter with 18 rotor blades followed by 19 stator blades at one‐fifth and 2 rotor blade chord distances. The spacings between the stator blades were varied with 5° and 10° modulation amplitudes. Farfield noise measurements made inside an anechoic test cell with symmetric and modulated blades showed significant changes in the directionality of the blade passing frequency tone with no apparent reductions in the peak tone levels. The generation and propagation of acoustic modes by rotor‐stator interaction for the case of modulated stator blades were theoretically examined in the light of the experimental results. Although the modes generated by symmetrical stators were attenuated, the sound energy was distributed to the additional modes thus causing no drastic reduction in the radiated energy.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
