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http://dx.doi.org/10.5139/JKSAS.2004.32.8.029

A Study on Subcritical Instability of Axisymmetric Supersonic inlet  

Shin, Phil-Kwon (충남대학교 기계공학부)
Park, Jong-Ho (충남대학교 기계공학부)
Publication Information
Journal of the Korean Society for Aeronautical & Space Sciences / v.32, no.8, 2004 , pp. 29-36 More about this Journal
Abstract
Supersonic inlet buzz can be defined as unstable subcritical operation associated with fluctuating internal pressures and a shock pattern oscillating about the inlet entrance. The flow pulsations could result in flameout in the combustor or even structural damage to the engine. An experimental study was conducted to investigate the phenomenon of supersonic inlet buzz on axisymmetric, external-compression inlet. An inlet model with a cowl lip diameter of 30mm was tested at a free stream Mach number of 2.0. Subcritical instability was investigated by considering the frequency of pressure pulsation and shock wave structure at the inlet entrance. The results obtained show that total pressure recovery ratios were varied from 0.42 to 0.78, and capture area ratio from 0.34 to 0.98. The frequency of the subcritical flow increased with decrease in capture area ratios. Frequency was measured at $224{\sim}240Hz$.
Keywords
Supersonic inlet; Instability; Buzz; Shock oscillation; FFT(Fast Fourier Transform); TR(Throttling Ratio);
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