AN EXPERIMENTAL STUDY OF PERPENDICULAR ACOUSTIC DISTURBANCES EFFECT ON FLOW OVER AN AEROFOIL AT LOW REYNOLDS NUMBERS
[ N/A ]
Tarih
2013
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Amer Soc Mechanical Engineers
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, the effect of perpendicular acoustic excitation on laminar separation bubble over a NACA2415 aerofoil and stall characteristics of the aerofoil was investigated experimentally at low Reynolds numbers (50000 and 75000) and various angles of attack on the aerofoil using force measurement, pressure measurement and smoke-wire flow visualization techniques. The experiments of resonance characteristics of test section of the wind tunnel showed that the frequencies used for acoustic control were not equal to the peak (resonance) frequencies of the wind tunnel test section. The experimental results of acoustic control showed that when acoustic excitation of a certain frequency was applied, the length of the laminar separation bubble was shortened owing to the energy added to the flow by acoustic excitation. Because of the shortened laminar separation bubble, coefficient of lift was increased. Furthermore, at the stall angles the separated flow was forced to reattach to the surface of the aerofoil, so the stall angle was increased from 12 degrees to 17 degrees and maximum coefficient of lift was increased from 1.16 to 1.24 at Re=50000 and from 13 degrees to 18 degrees and maximum coefficient of lift was increased from 1.18 to 1.34 at Re=75000.
Açıklama
ASME International Mechanical Engineering Congress and Exposition -- NOV 09-15, 2012 -- Houston, TX
Anahtar Kelimeler
Laminar Separation Bubble, Excitation
Kaynak
Proceedings of The Asme International Mechanical Engineering Congress and Exposition - 2012, Vol 7, Pts A-D
WoS Q Değeri
N/A
